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Proposed Rule2026-07294

Endangered and Threatened Species; Notice of 12-Month Findings on a Petition To List the Tope Shark as Threatened or Endangered Under the Endangered Species Act and Proposed Listing of Two Distinct Population Segments of Tope Shark as Threatened

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Published

April 15, 2026

Issuing agencies

Commerce DepartmentNational Oceanic and Atmospheric Administration

Abstract

We, NMFS, have completed a comprehensive status review of the tope shark (Galeorhinus galeus) in response to a petition to list the species as threatened or endangered under the Endangered Species Act (ESA) of 1973. After reviewing the best scientific and commercial data available, we have determined that this species is comprised of six distinct population segments (DPSs) and that two, the Southern (So.) Africa and Southwest (SW) Atlantic DPSs, are likely to become in danger of extinction throughout all or a significant portion of their ranges in the foreseeable future. Therefore, we propose to list the So. Africa and SW Atlantic DPSs as threatened species under the ESA. We have also determined that the remaining four DPSs--the Northeast (NE) Atlantic, NE Pacific, SW Pacific, and Southeast (SE) Pacific DPSs--do not meet the definition of a threatened or endangered species under section 4(a) of the ESA and therefore do not warrant listing under the ESA. We solicit information to inform the final listing determinations.

Full Text

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[Federal Register Volume 91, Number 72 (Wednesday, April 15, 2026)]
[Proposed Rules]
[Pages 20260-20315]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-07294]

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Vol. 91

Wednesday,

No. 72

April 15, 2026

Part II

Department of Commerce

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National Oceanic and Atmospheric Administration

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50 CFR Part 223

Endangered and Threatened Species; Notice of 12-Month Findings on a
Petition To List the Tope Shark as Threatened or Endangered Under the
Endangered Species Act and Proposed Listing of Two Distinct Population
Segments of Tope Shark as Threatened; Proposed Rule

Federal Register / Vol. 91 , No. 72 / Wednesday, April 15, 2026 /
Proposed Rules

[[Page 20260]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 260410-0096; RTID 0648-XR121]

Endangered and Threatened Species; Notice of 12-Month Findings on
a Petition To List the Tope Shark as Threatened or Endangered Under the
Endangered Species Act and Proposed Listing of Two Distinct Population
Segments of Tope Shark as Threatened

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of 12-month petition findings; proposed rule and request
for comments.

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SUMMARY: We, NMFS, have completed a comprehensive status review of the
tope shark (Galeorhinus galeus) in response to a petition to list the
species as threatened or endangered under the Endangered Species Act
(ESA) of 1973. After reviewing the best scientific and commercial data
available, we have determined that this species is comprised of six
distinct population segments (DPSs) and that two, the Southern (So.)
Africa and Southwest (SW) Atlantic DPSs, are likely to become in danger
of extinction throughout all or a significant portion of their ranges
in the foreseeable future. Therefore, we propose to list the So. Africa
and SW Atlantic DPSs as threatened species under the ESA. We have also
determined that the remaining four DPSs--the Northeast (NE) Atlantic,
NE Pacific, SW Pacific, and Southeast (SE) Pacific DPSs--do not meet
the definition of a threatened or endangered species under section 4(a)
of the ESA and therefore do not warrant listing under the ESA. We
solicit information to inform the final listing determinations.

DATES: Comments on this proposed rule must be received by June 15,
2026. Public hearing requests must be made by June 1, 2026.

ADDRESSES: A plain language summary of this proposed rule is available
at <a href="https://www.regulations.gov/docket/NOAA-NMFS-2022-0048">https://www.regulations.gov/docket/NOAA-NMFS-2022-0048</a>. You may
submit comments on the proposed rule, identified by NOAA-NMFS-2022-0048
by the following method:
<bullet> Electronic Submissions: Submit all electronic comments via
the Federal e-Rulemaking Portal. Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a> and
enter NOAA-NMFS-2022-0048 in the Search box. Click on the ``Comment''
icon, complete the required fields, and enter or attach your comments.
<bullet> Mail: Submit written comments to Adrienne Lohe, NMFS
Office of Protected Resources, 1315 East-West Highway, Silver Spring,
MD 20910.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
<a href="https://www.regulations.gov">https://www.regulations.gov</a> without change. All personal identifying
information (e.g., name and address), confidential business
information, or otherwise sensitive information submitted voluntarily
by the sender will be publicly accessible. NMFS will accept anonymous
comments (enter ``N/A'' in the required fields if you wish to remain
anonymous).
The petition, Status Review Report, Federal Register notices, and
the list of references can be accessed electronically online at:
<a href="https://www.fisheries.noaa.gov/species/tope-shark/conservation-management">https://www.fisheries.noaa.gov/species/tope-shark/conservation-management</a>. The peer review report is available online at: <a href="https://www.noaa.gov/organization/information-technology/peer-review-plans">https://www.noaa.gov/organization/information-technology/peer-review-plans</a>.

FOR FURTHER INFORMATION CONTACT: Adrienne Lohe, NMFS Office of
Protected Resources, 301-427-8442, <a href="/cdn-cgi/l/email-protection#9efffaecf7fbf0f0fbb0f2f1f6fbdef0f1ffffb0f9f1e8">[email&#160;protected]</a>, or Lisa
Manning, NMFS Office of Protected Resources, 301-427-8466,
<a href="/cdn-cgi/l/email-protection#167a7f6577387b7778787f7871567879777738717960">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

Background

On February 15, 2022, we received a petition from the Center for
Biological Diversity and the Defend Them All Foundation (Petitioners)
to list the tope shark, G. galeus, as a threatened or endangered
species under the ESA and to designate critical habitat concurrent with
the listing. The petition asserts that G. galeus is threatened by four
of the five ESA section 4(a)(1) factors: (1) present and threatened
destruction, modification, or curtailment of its habitat or range; (2)
overutilization for commercial and recreational purposes; (3)
inadequacy of existing regulatory mechanisms; and (4) other natural or
manmade factors. In addition to requesting that we analyze whether the
tope shark warrants listing based on its status throughout all or a
significant portion of its range, the petition requests that we analyze
whether any distinct population segments (DPS) of tope shark warrant
listing. The petition also requests that, if we determine the tope
shark or any DPSs of tope shark warrant listing as a threatened
species, we promulgate a protective regulation under section 4(d) of
the ESA, and requests that we promulgate a regulation under section
4(e) of the ESA for species similar in appearance to the tope shark.
On April 28, 2022, we published a 90-day finding announcing that
the petition presented substantial scientific or commercial information
indicating that the petitioned action may be warranted (87 FR 25209).
We also announced the initiation of a status review of the species, as
required by section 4(b)(3)(A) of the ESA, and requested information to
inform the agency's decision on whether this species warrants listing
as endangered or threatened under the ESA. In response to this request,
we received six public comments which expressed general support for
listing the tope shark under the ESA without providing any supporting
information.
Section 4(b)(3)(B) of the ESA requires that within 12 months of
receiving a petition that is found to present substantial scientific or
commercial information indicating that the petitioned action may be
warranted, the Secretary shall make a finding on whether the petitioned
action is warranted. On June 24, 2025, the Petitioners filed a
complaint seeking a court-ordered deadline for issuing the 12-month
finding; and pursuant to a court-approved settlement agreement, NMFS
was required to submit this finding to the Federal Register by April
15, 2026.

Listing Determinations Under the ESA

We are responsible for determining whether species under NMFS'
jurisdiction are threatened or endangered under the ESA (16 U.S.C. 1531
et seq.). To make this determination, we first consider whether a group
of organisms constitutes a ``species,'' which is defined in section 3
of the ESA to include ``any subspecies of fish or wildlife or plants,
and any distinct population segment of any species of vertebrate fish
or wildlife which interbreeds when mature'' (16 U.S.C. 1532(16)). On
February 7, 1996, NMFS and the U.S. Fish and Wildlife Service (FWS;
together, the Services) adopted a policy describing what constitutes a
DPS of a taxonomic species (``DPS Policy,'' 61 FR 4722). The joint DPS
Policy identifies two elements that must be considered when identifying
a DPS: (1) the discreteness of the population

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segment in relation to the remainder of the taxon to which it belongs;
and (2) the significance of the population segment to the remainder of
the taxon to which it belongs.
Section 3 of the ESA defines an endangered species as any species
which is in danger of extinction throughout all or a significant
portion of its range and a threatened species as any species which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range (16 U.S.C.
1532(6), 16 U.S.C. 1532(20)). Thus, an ``endangered species'' is one
that is presently in danger of extinction. A ``threatened species,'' on
the other hand, is not presently in danger of extinction, but is likely
to become so in the foreseeable future (that is, at a later time).
Under section 4(a)(1) of the ESA, we must determine whether any
species is endangered or threatened as a result of any one or a
combination of any of the following factors: (A) the present or
threatened destruction, modification, or curtailment of its habitat or
range; (B) overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence (16 U.S.C. 1533(a)(1); 50 CFR
424.11(c)). We are also required to make listing determinations based
solely on the best scientific and commercial data available, after
conducting a review of the species' status and after taking into
account efforts, if any, being made by any state or foreign nation (or
subdivision thereof) to protect the species (16 U.S.C. 1533(b)(1)(A)).
The status review (described in more detail below) and this
determination are based on analyses and information that are fully
consistent with the Gold Standard Science Executive Order (E.O. 14303)
in that they are reproducible; transparent; communicative of error and
uncertainty; collaborative and interdisciplinary; skeptical of findings
and assumptions; structured for falsifiability of hypotheses; subject
to unbiased peer review; accepting of negative results as positive
outcomes; and without conflicts of interest.

Status Review

To determine whether the tope shark warrants listing under the ESA,
a Status Review Report was completed (Manning, Rippe, and Lohe 2026),
which summarizes information on the species' taxonomy, distribution,
abundance, life history, ecology, and biology; identifies threats or
stressors affecting the status of the species; and assesses the
species' current and future extinction risk. We appointed three
biologists in the Office of Protected Resources Endangered Species
Conservation Division to compile and complete a scientific review of
the best scientific and commercial data available on the tope shark.
These biologists conducted an Extinction Risk Analysis to assess the
threats affecting the tope shark, as well as demographic risk factors
(abundance, productivity, spatial distribution, and diversity), using
the information in the scientific review. The Status Review Report
presents their assessment of the level of extinction risk facing the
tope shark but makes no recommendation as to the listing status of the
species.
The Status Review Report was subject to independent, unbiased peer
review pursuant to the Office of Management and Budget Final
Information Quality Bulletin for Peer Review (M-05-03; December 16,
2004). It was peer reviewed by seven independent specialists selected
from the academic and scientific community with expertise in tope shark
biology, conservation, or management. The peer reviewers were asked to
evaluate the adequacy, appropriateness, and application of data used in
the Status Review Report. All peer reviewer comments were addressed
prior to finalizing the Status Review Report and publication of this
finding.
We subsequently reviewed the Status Review Report, its cited
references, and peer review comments, and concluded that it synthesizes
the best available scientific and commercial information on the tope
shark. In making our listing determinations, we have applied the
statutory provisions of the ESA, including evaluation of the factors
set forth in section 4(a)(1)(A)-(E), our regulations in 50 CFR 424
regarding listing determinations, and relevant policies identified
herein.
The Status Review Report and the peer review report are available
electronically (see ADDRESSES). Below is a summary of the information
from the Status Review Report and our analysis of the status of the
tope shark.

Biological Review

Taxonomy and Species Description

The tope shark, G. galeus (Linnaeus 1758), is a member of class
Chondrichthyes, subclass Elasmobranchii (sharks and rays), order
Carcharhiniformes (ground sharks), and family Triakidae (houndsharks)
(ITIS and FishBase, accessed June 13, 2022). Once thought to each be
distinct species, other nominal species, including G. australis
(Macleay 1881), Galeus canis (Bonaparte 1841), G. chilensis
(P[eacute]rez Canto 1886), G. communis (Owen 1853), G. cyrano (Whitley
1930), G. linnei (Malm 1877), G. molinae (Philippi 1887), G. nilssoni
(Bonaparte 1846), G. vitaminicus (de Buen 1950), G. vulgaris (Fleming
1828), G. zyopterus (Jordan and Gilbert 1883), are now considered
synonyms of G. galeus (Compagno 1984; Fricke et al. 2022). Available
genetic data for G. galeus provide evidence of strong population
structuring by major geographic regions, but there is currently no
evidence supporting the identification of any subspecies (Chabot and
Allen 2009; Chabot 2015; Chiaramonte et al. 2016; Bester-van der Merwe
et al. 2017).
Other common names for this species have origins in the species'
appearance, behavior, or common uses. It is often called soupfin shark
in the United States and South Africa (also ``vaalhaai'' in South
Africa), school shark or snapper shark in Australia and New Zealand,
``caz[oacute]n'' (dogfish), ``tibur[oacute]n vitam[iacute]nico''
(vitamin shark), or ``tibur[oacute]n trompa de cristal'' (glass-snouted
shark) in Argentina and Uruguay, ``tibur[oacute]n aceitoso'' (oily
shark) or ``sulfin'' in Mexico, ``[ccedil][atilde]cao-bico-de-cristal''
(glass-snouted shark) in Brazil, ``tollo'' in Peru and Chile, and
``requin-h[acirc]'' in French-speaking countries of the NE Atlantic
(Walker 1999; Chiaramonte et al. 2016; Walker et al. 2020).
The tope shark is a medium-sized shark, generally reaching lengths
of about 183 centimeters (cm) (6 feet). Maximum reported lengths vary
by region, and range from a maximum total length (TL) of 155 cm for the
southwestern Atlantic (Peres and Vooren 1991) to 200 cm TL in the
Mediterranean Sea (Tunisian coast; Capap[eacute] and Mellinger 1988).
The body is slender and gray or grayish brown dorsally and whitish
ventrally, and young have black markings on their fins (Olsen 1984;
Compagno et al. 1989). The snout is long and pointed, with a wide,
crescent-shaped mouth. The small, triangular shaped teeth are serrated
on the outer edges (Olsen 1984; Compagno et al. 1989). The large and
horizontally oval eyes are positioned low on the sides of the head and
have a nictitating membrane (external in juveniles and internal in
adults and subadults), and the nostrils are positioned closer to the
mouth and upper lip than to the tip of the snout (Compagno 1984; Olsen
1984). The second dorsal and anal fins are of roughly the same height
and located opposite of each other, just anterior to the caudal
peduncle (Ripley 1946; Olsen 1984). The caudal fin is fairly short and

[[Page 20262]]

notched, with a well-developed lower lobe that gives it somewhat of a
double-tailed appearance (Olsen 1984).

Range, Distribution, and Habitat Use

Tope sharks occur in most of the world's oceans but have a
discontinuous range that includes parts of the North and South
Atlantic, North and South Pacific, Indian Ocean, and Mediterranean Sea
(Compagno 1984; Walker et al. 2020). More specifically, in the NE
Atlantic Ocean, they range from Iceland, Faroe Islands, Norway, United
Kingdom, Ireland, throughout the Mediterranean, southward to Cabo Verde
(Cape Verde) and Senegal. In the SW Atlantic, they range from southern
Brazil to Argentina. In the Eastern South Atlantic and Western Indian
Oceans, they range from Angola to South Africa. In the Western South
Pacific, they range from southern Australia to New Zealand. In the
Eastern North and South Pacific, they range from British Columbia,
Canada, south along the Baja California Peninsula and Gulf of
California, Mexico, and from Ecuador south to Peru and Chile. Following
the advent of improved species identification and reporting for sharks
in the Gulf of Alaska in 1997, at least one tope shark has been
documented in the Gulf of Alaska, but their occurrence in this region
is considered quite rare (King et al. 2017; Tribuzio et al. 2022).
Within the Mediterranean Sea, tope sharks are known to occur mainly in
western parts of the sea, but do extend farther, including rare
occurrences in the Adriatic Sea (Tsagarakis et al. 2021). There are no
records of tope sharks in the Sea of Marmara or the Black Sea (Colloca
et al. 2019). Occurrence of tope sharks is questionable along western
Africa, from roughly Gambia and Guinea-Bissau to the Democratic
Republic of the Congo, as well as off Mozambique in southeastern Africa
and off Laysan Island in the Northwestern Hawaiian Islands (Cadenat and
Blanche 1981; Compagno 1984; Compagno et al. 2005; Walker et al. 2020;
<a href="https://www.fishbase.org">https://www.fishbase.org</a>). Although observations of tope shark within
intertropical western Africa are recorded in FishBase (<a href="https://www.fishbase.org">https://www.fishbase.org</a>, last accessed on February 23, 2026), it is possible
these are misidentifications, as other researchers specifically report
having no observations of tope sharks in this region, and there are no
reported catches of tope sharks in the Food and Agriculture
Organization (FAO) of the United Nations (UN) fishery database for this
region (<a href="https://www.fao.org/fishery/en/collection/capture">https://www.fao.org/fishery/en/collection/capture</a>).
Tope sharks are semi-pelagic and occur in shallow coastal areas, in
continental shelf and slope waters, and in oceanic waters (Compagno
1984; Walker 1999; Thorburn et al. 2019; Walker et al. 2020; Schaber et
al. 2022). Distribution patterns and movements of tope sharks are
complex and vary with multiple factors, including size, sex, habitat,
and season. Immature tope sharks are typically found in coastal areas
and in waters less than 200 meters (m) deep, with the smallest
individuals (e.g., <40 cm) remaining in shallower, coastal areas and
larger juveniles having more expanded distributions (Olsen 1954; Olsen
1984; Stevens and West 1997; McAllister et al. 2015; Thorburn et al.
2019). Adult tope sharks occur in continental and insular shelf and
slope waters, but also use pelagic, open-ocean areas and have been
tracked at depths up to 826 m (Ripley 1946; Olsen 1984; Thorburn et al.
2019; Schaber et al. 2022).
Tagging studies indicate that while tope sharks can undertake long-
distance migrations, they also exhibit general fidelity to a region. In
several tagging studies, most sharks returned to or remained within 500
kilometers (km) of where they were initially released, while some
sharks were recaptured thousands of kilometers away (Holden and Horrod
1979; Stevens 1990; Hurst et al. 1999; Brown et al. 2000; Fitzmaurice
et al. 2003; Thorburn et al. 2019). The average distance that tope
sharks range increases with size and age of the sharks (Stevens and
West 1997; Brown et al. 2000; Thorburn et al. 2019). Medium and large-
sized females are often recaptured at farther distances on average than
males of the same size class (Brown et al. 2000; Francis 2010; Thorburn
et al. 2019; Cameron et al. 2025). However, several studies have found
that some adult females travel similar distances as the adult males
(Brown et al. 2000; Walker et al. 2000; Francis 2010; Thorburn et al.
2019). Some researchers have hypothesized that this pattern of
``partial female migration'' reflects, at least in part, the use of
local pupping areas by some females and use of more distant pupping
areas by others (McMillan et al. 2019; Thorburn et al. 2019).
Additional data are needed to understand the extent to which adult
females display diversity in their use of pupping areas.
Spatial segregation of adult male and female tope sharks has been
reported from many parts of its range including Australia (Olsen 1954;
Olsen 1984; Walker 1999), California (Ripley 1946; Nosal et al. 2021),
Argentina (Lucifora et al. 2004), South Africa (Freer 1992), Ireland
(Fitzmaurice et al. 2003, Cameron et al. 2025), Scotland (Stevens 1990,
Little 1995), England (Holdon and Harrod 1979), and the Alboran Sea
(Mu[ntilde]oz-Ch[aacute]puli 1984), indicating this is a common
behavior within the species.
Tope sharks exhibit various migratory patterns that are often
generally described as involving migration towards the poles during
warmer months and migration towards the equator or into deeper,
offshore waters during colder months (de Buen 1952; Olsen 1954, 1984;
Lucifora et al. 2004; Thorburn et al. 2019). For example, in the SW
Atlantic, tope sharks are present in greatest abundance off the coast
of southern Brazil from June through September and move southward to
Argentina by austral summer, peaking in abundance in Puerto
Quequ[eacute]n (around 38[deg]32' S) from September to December, in
Anegada Bay (around 40[deg]30' S) from October to December, and gulfs
further south (around 43[deg] S) between January and April (Peres and
Vooren 1991; Ferreira and Vooren 1991; El[iacute]as et al. 2005;
Lucifora et al. 2004; Chiaramonte 2015; Klippel et al. 2016; Trobbiani
et al. 2021). These seasonal movement patterns are thought to be driven
by oceanographic conditions, particularly by the seasonal shift in the
front between the warm, subtropical, Brazil Current and the cold,
subantarctic Malvinas (Falkland) Current and the associated changes in
water temperature (Klippel et al. 2016). A slightly different pattern
occurs in the NE Atlantic, where tope sharks exhibit a cyclical
seasonal movement pattern rather than north-south migration. Evidence
from tagging and mark-recapture studies here show migration away from
tagging sites and into deeper waters during winter and spring, and a
return to coastal areas or areas close to (within about 50 km of) their
original tagging site during summer and fall, consistent with the
observed timing of mating in the region (Fitzmaurice et al. 2003;
Thorburn et al. 2019).
Tope sharks also exhibit different patterns of vertical movement
and use epipelagic (0-200 m depths) as well as mesopelagic habitats
(200-1,000 m depths), depending on several factors including time of
day and bathymetry (West and Stevens 2001; Thorburn et al. 2019;
Gonzalez-Garcia et al. 2020; Schaber et al. 2022). The vertical
movements observed in tope sharks may be related to feeding behavior,
including searching for prey (Cuevas et al. 2014; Schaber et al. 2022).
During spring and summer, pregnant females are often observed in
shallow, coastal areas typically to give birth (Olsen 1984; Ripley
1946). Repeated observations of neonates, immediately

[[Page 20263]]

post-partum females and/or late-stage pregnant females have been used
to confirm specific pupping and nursery areas in certain regions,
although they have not been identified or fully resolved across the
range. Within southeastern Australia, a number of bays and estuaries in
Victoria and Tasmania have been identified as tope shark pupping and
nursery areas, including the estuaries of Port Sorell, Pittwater,
Georges Bay, and Great Oyster Bay in Tasmania, and Port Phillip Bay and
Western Port Bay in Victoria (Olsen 1954, 1984; Steven and West 1997;
Xiao et al. 1999) and potentially inshore areas of the Great Australian
Bight (Prince 1996; Braccini et al. 2009; Rogers et al. 2017; M.N.
McMillan unpublished, cited in McMillan et al. 2018). Stevens and West
(1997) estimated that known pupping areas in southeastern Australia
account for less than 10 percent of pup production needed to sustain
the Australia tope shark stock, suggesting that other pupping areas
exist. In New Zealand, pupping areas may be limited to coastal waters
between the Hauraki Gulf and Kaipara Harbor along the North Island and
between Oamaru and Jackson Bay along the South Island (Blackwell and
Francis 2010; International Union for Conservation of Nature (IUCN)
Species Survival Commission (SSC) Shark Specialist Group 2024a,b).
However, Fisheries New Zealand (2024b) reports that the geographic
location of the most important pupping and nursery grounds in New
Zealand is not known. Available evidence indicates that pupping occurs
throughout the Northeast Atlantic including near mainland Portugal, the
Canary Islands, the Azores, inshore waters of England, Wales, and
Ireland, and in the southern North Sea (Mu[ntilde]oz-Ch[aacute]puli
1984; J.R. Ellis pers. comm., cited in Walker 1999; Thorburn et al.
2019; Schaber et al. 2022; Das et al. 2025; Edwards et al. 2025; IUCN
SSC Shark Specialist Group 2025a,b,c; Loughs Agency n.d.; National
Museums Northern Ireland n.d.). It is unclear if pupping occurs within
the Mediterranean (Capap[eacute] et al. 2005). In the SW Atlantic,
pupping and nursery habitats are thought to be located in inshore
waters of northern Argentina, and may include Bah[iacute]a Blanca,
Bah[iacute]a de Samboromb[oacute]n, Bah[iacute]a San Blas, Bah[iacute]a
Enga[ntilde]o and Golfo San Mat[iacute]as, as well as the
Albard[atilde]o region off Rio Grande do Sul, Brazil (G.E. Chiaramonte,
pers. comm., cited in Walker 1999; Lucifora et al. 2004; Bovcon et al.
2018; IUCN SSC Shark Specialist Group 2025e). In South Africa, pupping
has been reported to occur in the Gansbaai area and juvenile tope
sharks have been caught in various embayments, including Struis, St.
Helena, Walker, and False Bay, suggesting that these and/or nearby
coastal areas may function as pupping or nursery grounds (Freer 1992;
McCord 2005). Finally, in the NE Pacific, pupping areas include (or
historically included) central California, the Santa Barbara coast,
Tomales and San Francisco Bay, and potentially areas off Baja
California Sur (Ripley 1946; Ram[iacute]rez-Amaro et al. 2013; Nosal et
al. 2021). No information is available on pupping or nursery areas in
the SE Pacific.

Diet

Tope sharks prey on a wide range of demersal and pelagic fishes, as
well as crustaceans, cephalopods, worms, and echinoderms (Compagno
1984). The diet of the species changes significantly with their
development: juveniles consume more crustaceans and benthic
invertebrates than adults, while adults consume a greater diversity of
fishes and overall higher trophic level prey relative to juveniles
(Lucifora et al. 2006; Taborda 2018; Poiesz et al. 2021; Priester et
al. 2024). Differences in the diet of males and females have been
observed in some studies, although this could be explained by habitat
use and seasonality rather than diet preferences (Ripley 1946).
Although data are limited, tope sharks appear to be somewhat selective
rather than strictly opportunistic foragers (Lucifora et al. 2006;
Biton-Porsmoguer 2022). Detailed information on prey species by region
is available in section 2.5 of the Status Review Report.

Growth and Reproduction

Tope sharks are relatively long-lived, reaching a maximum age of at
least 55 years (Coutin 1992; Walker et al. 2020). Because sharks lack
the calcified structures (e.g., otoliths) typically used to age
teleosts (bony fishes), age and growth estimates are often produced by
counting vertebral growth bands or by using time at liberty and
differences in length measurements collected during mark-recapture
studies (Cailliet and Goldman 2004; Cailliet 2015; Harry 2018). For
tope sharks, counting growth bands is considered reliable for small and
medium-sized individuals but is likely to underestimate the age of
older, larger individuals (i.e.,>=140 cm total length (TL) or >=~11
years old) and therefore mark-recapture studies likely produce more
accurate maximum age estimates (Moulton et al. 1992; Walker et al.
2001; Harry 2018). Studies relying on counts of vertebral bands have
produced maximum age estimates on the order of 33 years for tope sharks
off the coast of South Africa (Freer 1992; McCord 2005), 41 years for
tope sharks off the coast of Brazil (Ferreira and Vooren 1991), and 50
years in Australia (Thomson et al. 2020). Studies using tag-recapture
growth data have produced maximum age estimates ranging from 46-59
years for females (n = 37) and 43-55 years for males (n = 16) in the NE
Atlantic (Dureuil and Worm 2015), and 55 years to possibly 60 years for
tope sharks tagged off southern Australia (Olsen 1953, 1954; Walker
1999).
Tope sharks exhibit fairly slow overall growth rates. Available
estimates of von Bertalanffy's growth coefficient (K) for tope sharks
are 0.164 year-1 in Australia, 0.075 year-1 for
females and 0.092 year-1 for males in Brazil, 0.124
year-1 in Australia, 0.086 year-1 for females and
0.154 year-1 for males in New Zealand, 0.190
year-1 in South Africa, and 0.076 year-1 for
females and 0.081 year-1 for males in the NE Atlantic (Grant
et al. 1979; Ferreira and Vooren 1991; Moulton et al 1992; Francis and
Mulligan 1998; McCord 2005; Dureuil and Worm 2015). Higher growth
coefficients for males suggests that they reach their maximum lengths
faster than females. Individuals grow most quickly during the first
several years, followed by steady growth up to age 7-11 years, slowed
growth as they approach or reach maturity, and then an eventual plateau
(Grant et al. 1979; Moulton et al. 1992; Francis and Mulligan 1998;
Fitzmaurice et al. 2003; McCord 2005). Relative to females, male tope
sharks reach maturity at smaller sizes and earlier ages, and attain
slightly smaller maximum lengths and lower weights (Ripley 1946; Grant
et al. 1979; Freer 1992; Lucifora et al. 2004; Capap[eacute] et al.
2005; Walker 2005). Maximum theoretical length ranges from 163-201 cm
for females and 142-177 cm for males (Ferreira and Vooren 1991; Francis
and Mulligan 1998; Dureuil and Worm 2015). Tope sharks have an
estimated age at maturity ranging from about 10 to 15 years in females,
and 6 to 17 years in males. Length at first maturity ranges from 118-
150 cm in females and 107-135 cm in males. Tope sharks are therefore
considered a late-maturing species. Additional information on age and
growth parameters for the species can be found in Table 2-1 of the
Status Review Report.
Tope sharks exhibit yolk sac viviparity, meaning that eggs are
fertilized and hatched internally, young are born alive, and
nourishment of the embryo comes from the egg rather than from a
placental connection to the

[[Page 20264]]

mother. Gestation is thought to last 12 months (Ripley 1946; Peres and
Vooren 1991; Lucifora et al. 2004; Capap[eacute] et al. 2005); however,
Theron (2001) and Walker (2005) suggest it may exceed 12 months. Data
from multiple locations across the species' range, including Argentina,
Brazil, southern Australia, South Africa, and California, provide
evidence of a triennial (3-year) female reproductive cycle (Peres and
Vooren 1991; Theron 2001; Lucifora et al. 2004; Walker 2005; Nosal et
al. 2021). Males are thought to reproduce annually, and mating occurs
seasonally within a local population (Peres and Vooren 1991; Freer
1992; Theron 2001). Females are capable of storing sperm for periods of
weeks to months, and therefore mating may occur well in advance of
fertilization (Peres and Vooren 1991; Theron 2001; Walker 2005). There
is also evidence of multiple paternity (i.e., multiple sires in the
same litter) in tope sharks (Hernandez Mu[ntilde]oz 2013; Kelly et al.
2025). Female fecundity increases with the size of the adult female as
evidenced by increased number of oocytes per female, number of embryos
per female, and number of pups per litter in larger females (Ripley
1946; Olsen 1984; Peres and Vooren 1991; Lucifora et al. 2004;
Capap[eacute] et al. 2005; Walker 2005; Chiaramonte 2015). Litter size
can range from 4-52 pups, with average litter size ranging from about
23-35 pups of equal sex ratio measuring approximately 240-370
millimeters (mm) total length (TL) (Ripley 1946; Peres and Vooren 1991;
Freer 1992; Walker 2005).

Demography

The natural mortality rate (M) for tope sharks, which theoretically
accounts for predation and all other natural sources of mortality, such
as senescence, has been estimated to be low (M = 0.1006
year-1) for tope sharks of mixed age in Australia (95
percent confidence range: 0.08-0.12, n = 500; Grant et al. 1979). This
is equivalent to a survival rate (from natural death) of
e-0.1006 = 90.43 percent year-1. Estimates of
natural mortality for tope sharks in other regions are also generally
low: 0.123 year-1 in Australia, 0.26 year-1 in
Australia, 0.126 year-1 in South Africa, and 0.094
year-1 in the NE Atlantic (Walker 1970 as cited in Walker
1999; Dow 1986 as cited in Walker 1999; McCord 2005; Dureuil 2013).
The intrinsic rate of population increase (r<INF>max</INF>), which
is a function of fecundity, age of maturity, longevity, and natural
mortality rate, is fairly low for tope shark populations. Using life
history data available through FishBase (<a href="https://www.fishbase.org">https://www.fishbase.org</a>),
life history parameter estimation software available through FishLife
2.0 (Thorson et al. 2017; Thorson et al. 2023), and a Leslie-matrix
approach, Winker et al. (2019) calculated an r<INF>max</INF> value of
0.041 (CV = 0.154) for tope sharks. Using five different methodologies,
Cort[eacute]s (2016) calculated r<INF>max</INF> values of 0.042-0.086
for tope sharks in the SW Atlantic and 0.047-0.169 for tope sharks in
the SW Pacific. Smith et al. (1998) developed a model that uses female
age at maturity, maximum reproductive age, and average fecundity to
calculate a productivity metric referred to as the intrinsic rebound
potential (IRP), which essentially estimates potential population
growth rate after harvest mortality is removed. Using biological data
collected for tope sharks in southern Australia and under an assumption
of no increase in fecundity, Smith et al. (1998) calculated an IRP of
0.033 and a corresponding population doubling time of 21.3 years. Under
an assumed 25 percent increase in fecundity (to account for increased
survival of older, larger females), the IRP increased to 0.045 with an
associated doubling time of 15.4 years (Smith et al. 1998). Across the
26 shark species considered in their comparative analysis, these
authors found a wide range of rebound rates (i.e., 0.017-0.202), with
the tope shark among the species estimated to have a relatively low to
moderate IRP (Smith et al. 1998).
Winker et al. (2019) estimated a median generation length of 23.1
years (CV = 0.066). Similarly, the most recent IUCN Red List assessment
of tope shark applied a similar estimated generation length of 26.3
years (Walker et al. 2020), while the Australian Fisheries Management
Agency (AFMA), in their rebuilding strategy for the species, uses an
estimated generation length of 22 years (AFMA 2015).

Population Structure

Tagging and genetic data indicate that G. galeus is structured as
at least six regional populations: (1) a NE Atlantic population that
extends from the North Sea and UK waters into the Mediterranean Sea and
southward to northwest Africa; (2) a So. Africa population that extends
from Namibia to East London, South Africa; (3) a SW Atlantic population
that ranges from southern Brazil to Patagonia; (4) a NE Pacific
population that ranges from British Columbia, Canada to southern Baja
California, Mexico, and including the Gulf of California; (5) a SE
Pacific population that ranges from Ecuador to Chile; and (6) a SW
Pacific population that includes Australia and New Zealand. No movement
of tope sharks among these regions has been reported, and available
genetic data indicate that gene flow among these six regional
populations is limited (Ward and Gardiner 1997, Chabot and Allen 2009,
Chabot 2015, Hern[aacute]ndez et al. 2015, Bester-van der Merwe et al.
2017).
Current understanding of tope shark population structure is based
largely on several studies that examined population genetics of tope
sharks on broad geographic scales. Most recently, Bester-van der Merwe
et al. (2017) investigated population structure of tope sharks by
collecting and analyzing genetic samples from five countries:
Argentina, Chile, South Africa, Australia (Tasmania), and New Zealand.
Genetic variation was assessed based on both nuclear DNA (nDNA) (19
microsatellite markers, n = 185 samples) and mitochondrial DNA (mtDNA)
(n = 96 samples). Similarly, a pair of studies by Chabot and Allen
(2009) and Chabot (2015) used both microsatellites (n = 11 markers) and
an mtDNA marker (1,068-base pair fragment in the control region) to
investigate the population structure of tope sharks from multiple
locations across the species range: South America (Peru, n = 11;
Argentina, n = 1), South Africa (Cape Town, n = 16), Australia (GAB,
New South Wales, and Tasmania, n = 50), North America (Southern
California, n = 26), and the United Kingdom (Irish and Celtic Seas, n =
12). (Note: Chabot (2015) pooled their single sample from Argentina
with the Peru samples into a collective South America population based
on the observation of Chabot and Allen (2009) that it shared an
identical mtDNA haplotype with two samples from Peru.) All three
studies detected a high degree of genetic differentiation among the
sampled regions (Bester-van der Merwe et al. 2017: F<INF>CT</INF> =
0.137, [Fcy]<INF>ST</INF> = 0.895, p < 0.05; Chabot and Allen 2009:
[Fcy]<INF>ST</INF> = 0.84, p < 1 x 10-6; Chabot 2015:
F<INF>CT</INF> = 0.15, p < 0.001). The results of pairwise comparisons
between regions provide additional support for population structuring
at a regional scale. For instance, pairwise comparisons by Bester-van
der Merwe et al. (2017) using microsatellite data indicated significant
but varying magnitudes of genetic differentiation between all sampled
regions (F<INF>ST</INF> = 0.050 to 0.330, p < 0.05), with the lowest
observed differentiation occurring between Chile and New Zealand
(F<INF>ST</INF> = 0.050) and highest between Argentina and Australia
(F<INF>ST</INF> = 0.330). Similarly, pairwise comparisons by Chabot
(2015) using microsatellite data and three different statistics
(F<INF>ST</INF>, G''<INF>ST</INF>, and Jost's D) consistently indicated
significant genetic

[[Page 20265]]

differentiation between all sample regions. Pairwise comparisons by
Chabot and Allen (2009) using mtDNA also revealed significant
differences ([Fcy]<INF>ST =</INF> 0.34-0.90, p < 1 x 10-6)
for all pairs, and, based on [Fcy]<INF>ST</INF> values, among-
population differences accounted for 83.96 percent of the observed
genetic variation. These researchers identified 38 unique haplotypes, 2
of which were shared between sampling regions. One, as noted earlier,
was shared between Argentina and Peru, and the other was shared between
South Africa and Australia. With the exception of Australia and New
Zealand, all pairwise comparisons of mtDNA in Bester-van der Merwe et
al.'s (2017) study also indicated significant and strong population
structuring ([Fcy]<INF>ST</INF> = 0.151-0.934, p < 0.05), with the
lowest difference between Chile and Argentina ([Fcy]<INF>ST</INF> =
0.151). Bester-van der Merwe et al. (2017) identified 15 unique
haplotypes, one of which was shared between Chile and Argentina and one
between Australia and New Zealand. The very low and non-significant
measure of pairwise variation for the mtDNA marker between Australia
and New Zealand ([Fcy]<INF>ST</INF> = -0.180) reported by Bester-van
der Merwe et al. (2017) is an exception to the otherwise consistent
pattern of significant genetic differentiation among sampled regions.
An earlier study by Hern[aacute]ndez et al. (2015) also examined
genetic samples from Australia and New Zealand using a different mtDNA
marker, 8 microsatellite markers (versus 19), more sample locations
within each country, and substantially more mtDNA samples and
microsatellite samples than Bester-van der Merwe et al. (2017). Results
of Hern[aacute]ndez et al.'s (2015) study indicated that genetic
differentiation between the Australia and New Zealand samples based on
mtDNA was low and non-significant (after sequential Bonferroni
correction, [alpha] = 0.0014), and that the microsatellite variation
was also low and non-significant (p > 0.05; Hern[aacute]ndez et al.
2015).
Estimates of gene flow (in terms of migrants per generation) by
Chabot and Allen (2009) among sampled locations were very low and
ranged from 0.05 to 0.97. Estimates of gene flow by Chabot (2015)
between sampled locations were also very low (0.002-0.013), with the
exception of the migration rate from South into North America, which
was higher than all others (0.257). However, the estimated migration
between North and South America in this study was well below the
estimated self-recruitment rates (0.692 and 0.988); and, as discussed
earlier, the pairwise comparisons between North and South America based
on mtDNA and microsatellites showed significant genetic differentiation
(Chabot and Allen 2009; Chabot 2015).
Overall, and notwithstanding data gaps due to under- and non-
sampled parts of the range, these studies indicate a regionally
isolated population structure, with little to no contemporary
connectivity between tope shark populations across ocean basins or the
equator. Additional information about finer-scale population structure
is available in section 2.8 in the Status Review Report (see also
Distinct Population Segment Analysis section of this document).

Population Abundance and Trends

A global abundance estimate for tope sharks is not available;
however, the most recent IUCN Red List assessment (Walker et al. 2020)
provides a trend analysis for the species on a range-wide level as well
as several regions. This analysis was based on the following data from
five geographic locations and four of the six regional tope shark
populations (the NE and SE Pacific populations were omitted): (1)
standardized catch per unit effort (CPUE) data for the NE Atlantic from
fisheries-independent trawl surveys and the Azorean bottom long-line
fishery (International Council for the Exploration of the Sea (ICES)
2019); (2) nominal CPUE data from the demersal trawl fisheries in
Argentina (G. Chiaramonte unpublished data 2019); (3) estimated biomass
trends from a stock assessment for South Africa (Winker et al. 2019);
(4) estimated biomass trends from a stock assessment for Australia
(Thomson and Punt 2009); and (5) standardized CPUE from longline and
gillnet surveys in New Zealand (Dunn and Bian 2018). The trend data
from each source were analyzed over three generation lengths using a
Bayesian state-space modeling tool specifically designed for use in
IUCN Red List assessments for pelagic sharks, referred to as the `Just
Another Red List Assessment' (JARA) tool (see Sherley et al. 2020).
This modeling tool was built off of the existing and open-source
software referred to as `Just Another Bayesian Biomass Assessment'
(JABBA), which is an extension of a standard Surplus Production Model
framework that incorporates a Bayesian approach to account for
potential process (i.e., model-based) and observation (i.e., sampling-
based) error (Winker et al. 2018). The JARA analysis yields an annual
rate of change, a median percentage change over three generation
lengths, and the probability of the most likely IUCN Red List Category.
Population trends were estimated using the JARA framework for each
of the five datasets mentioned above, and those regional trend
estimates were then used to estimate a global population trend, with
regional trend data weighted by the size of the particular region in
proportion to the species' total distribution. This analysis estimated
a median percentage decline of -76.6 percent, -99.3 percent,-91.4
percent, -90.1 percent, and -29.8 percent over three generations (79
years) for the NE Atlantic, SW Atlantic, So. Africa, Australia, and New
Zealand populations, respectively, and a global decline of -88 percent
(95 percent CI: -99.6 to -65.7 percent) (Walker et al. 2020, see
Supplemental Information). However, the authors do note several
important caveats. For example, to incorporate regions where the
species is known to occur but where trend data were not available
(e.g., NE Pacific, SE Pacific), Walker et al. (2020) assumed that each
missing regional population had declined by between 0 and 100 percent
by randomly sampling from a uniform distribution, U(-100,0), and then
combined this value (weighted by proportional area) with other regional
estimates to calculate the global trend. Additionally, when datasets do
not span three generation lengths, as was the case for all the regions
in this analysis, JARA requires that trends be projected forward in
time, effectively extrapolating beyond the available data and
compounding the uncertainty in the estimated trends. For several
regions (i.e., NE Atlantic, SW Atlantic, and New Zealand), these
extrapolations represented approximately two-thirds of the time series
used in the analysis. Overall, given the lack of long-term monitoring
for this species, each regional trend estimate was necessarily derived
from very limited information--sometimes just a single fishery-
dependent CPUE series or assessment--which may not capture important
underlying factors, such as stock structure, age and size composition,
or regional differences in fishing practices (see also Kai 2021).
Available information on abundance and trends by region is discussed
below.
In some cases, stock assessments have been conducted on the
regional tope shark population to evaluate the status of the stock for
fisheries management purposes. Stock assessments often indicate the
status of a stock using the terms ``overfished'' and ``overfishing.''
Specific to the context of the Magnuson-Stevens Fishery Conservation
and Management Act (MSA), a stock or stock

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complex is considered ``overfished'' when its biomass has declined
below minimum stock size threshold (MSST), defined as the level of
biomass below which the capacity of the stock or stock complex to
produce maximum sustainable yield (MSY) on a continuing basis has been
jeopardized (50 CFR 600.310(e)(2)(i)(E)-(F)). Overfishing occurs
whenever a stock or stock complex is subjected to a level of fishing
mortality or total catch that jeopardizes the capacity of a stock or
stock complex to produce MSY on a continuing basis (50 CFR
600.310(e)(2)(i)(B)). While the stock assessments referenced in this
finding do not define ``overfished'' and ``overfishing'' using the
exact language above, they use the two terms with equivalent meanings.
It is important to note that the terms ``overfished'' and
``overfishing'' do not have any specific relationship to the terms
``threatened'' or ``endangered'' as defined in the ESA. While a stock
that is overfished is not able to sustain an exploitive fishery at MSY
(i.e., the highest possible annual catch that can be sustained over
time), it can still be at a stable biomass level and thus not in danger
of extinction due to overutilization. Similarly, one goal of the MSA
(and fisheries management organizations) is to ``rebuild'' overfished
stocks to biomass levels that will support MSY. This level can be
significantly above the biomass levels necessary to ensure that a
species is not in danger of extinction. Thus, evidence of declining
abundance that threatens the ability of the fishery to provide MSY is
relevant, but not dispositive of a threatened or endangered species
determination. Therefore, while available information about whether
specific stocks are overfished or experiencing overfishing is relevant
to and considered in the ESA extinction risk analysis, the fact that a
stock may be considered ``overfished'' or experiencing ``overfishing''
does not automatically indicate that any particular status is
appropriate under the ESA. Stock assessments, which provide information
for determining the sustainability of a fishery, are based on different
criteria than status reviews conducted under the ESA, which provide
information to assess the likelihood of extinction of the species. When
conducting a status review under the ESA, we use relevant information
from available stock assessments, such as levels of biomass and fishing
mortality, and apply the ESA's definitions of threatened and endangered
species to the information in the record using NMFS' standard tools of
ESA extinction risk analysis. As part of the ESA extinction risk
analysis, when examining whether overutilization for commercial
purposes is a threat to the species, the status review considered
whether the species has been or is being harvested at levels that
contribute to or pose a risk of extinction to the species.
NE Atlantic
Quantitative data on abundance trends of G. galeus in the NE
Atlantic region are limited. While several fishery-independent surveys
are available from across the region, there are various design and
sampling flaws or errors preventing us from drawing strong conclusions
about population trends. Five research surveys coordinated by ICES and
spanning 1992 to 2022 were considered by the ICES Working Group on
Elasmobranch Fisheries (WGEF) in their 2023 review of the tope shark.
Tope sharks are not sampled effectively in these surveys due to low
gear selectivity, and therefore, trend analyses using these data should
be ``viewed with care'' (ICES 2022). However, one of the five surveys,
International Bottom Trawl Survey (IBTS)-Q1, had a low catch rate of
tope sharks over the time period and was not subject to further
analysis by WGEF (ICES 2023a), and a second of these surveys, IBTS-Q3,
included some questionable data and species identification issues such
that the WGEF concluded the dataset could not be relied upon until the
data could be verified (ICES 2022). Two other trawl surveys considered
by the WGEF are France's ``Evaluation Halieutiques Ouest de l'Europe''
Groundfish Survey (EVHOE-WIBTS-Q4), which is conducted in the Bay of
Biscay and Celtic Sea, and the Irish Groundfish Survey (IGFS-WIBTS-Q4),
which is conducted in the shelf waters around Ireland (ICES 2023a).
Neither dataset indicates a clear abundance trend: the data show
sporadic peaks in annual catch generally related to a large number of
specimens captured in single hauls (ICES 2023a). The fifth survey
considered by the WGEF is the spring bottom longline survey of waters
around the Azores archipelago (ARQDA[Ccedil]O) that has been conducted
almost annually since 1995. The survey is not particularly well-suited
to capturing tope sharks, and both the biomass estimates and
standardized abundance index derived from these survey data are highly
variable over time and do not indicate a clear trend (ICES 2023a).
Santos et al. (2020) analyzed ARQDA[Ccedil]O survey data and compared
them to commercial landings data, and reported that annual landings for
tope sharks showed a decreasing trend from 1998/2000 to 2009, and then
some rebound after this period. Santos et al. (2020) hypothesized that
the relatively lower landings in the more recent years reflect an
increased discard rate, which may have been driven in part by low
market demand. This hypothesis receives some support from their finding
that the standardized CPUE for tope sharks in the fisheries data is
fairly stable over time. The authors cautioned that neither the
abundance index nor the CPUE data should be interpreted as an accurate
proxy for tope shark abundance in the region due to the low and
variable catch rates of tope sharks and likely changes in discard rates
in the longline fisheries.
As part of the most recent IUCN Red List assessment of tope sharks,
Walker et al. (2020) assessed trends for the entire NE Atlantic
regional population of tope sharks using three datasets: the Bay of
Biscay and Celtic Sea trawl surveys (i.e., EHVOE-WIBTS-Q4) from 1997-
2016; the Irish Ground Fish Survey (i.e., IGFS-WIBTS-Q4) from 2005-
2018, and the Azorean bottom long-line fishery landings during 1990-
2015 (see Walker et al. 2020, Supplementary Information). Results of
the JARA analysis using these three datasets indicate an annual rate of
reduction of 1.7 percent for the combined 29 years of survey data
(1990-2018) and projected an estimated median reduction of 76.6 percent
over the next three generations (79 years). Walker et al. (2020) noted
that this trend was largely driven by the higher catch rates occurring
at the start of the time-series, with data from the latter part of the
time-series indicating more stable trends. The authors also reiterated
the concerns raised by the WGEF that the various datasets for the NE
Atlantic may not be representative of the population due to low
catchability of tope sharks in the surveys and gears used and therefore
cautioned how the data were interpreted. In addition, the 95 percent
credible intervals on the model-predicted population trend are wide and
skewed upwards over the forecasted three generations. Lastly, it is
also worth noting that the more recent years (i.e., since 2018) of
trawl survey data from EHVOE-WIBTS-Q4 (Bay of Biscay and Celtic Sea) in
which CPUE and biomass estimates show some increases are not captured
in this analysis as these data were likely not available at the time.
Beyond these available survey data, additional, reliable
quantitative data regarding tope shark abundance trends in the North
Atlantic Ocean are very limited. Some data, however, are available from
the Irish Marine Sportfish Tagging Program, which

[[Page 20267]]

between 1970 and 2015, recorded 448 recaptures of 7,641 tagged tope
sharks (ICES 2020). Using Jolly-Seber mark-recapture modeling, the WGEF
reported that these data indicate a stable population trend around
Ireland between 1970 and 2015 (ICES 2020).
Within the Mediterranean and Black Seas, fishery-independent survey
data are available from the Mediterranean International Trawl Survey
(MEDITS), an international survey effort formalized in 1993 by Spain,
France, Italy and Greece, and expanded in 1996 to include Albania,
Croatia and Slovenia. These standardized bottom-trawl surveys have been
conducted since 1994 throughout 19 subregions along the northern margin
of the Mediterranean basin. Encounters with tope sharks are generally
infrequent, varying by geographical subarea (GSA) (Relini et al. 2010;
Marongiu et al. 2017, Ram[iacute]rez-Amaro 2017; Geraci et al. 2017;
Follesa et al. 2019). Ram[iacute]rez-Amaro (2020) provided MEDITS
summary data for 199 hauls completed during 1994-2015 in the western
Mediterranean, specifically the northern Alboran Sea (GSA 1),
northeastern coast of Spain (GSA 5), and Balearic Islands (GSA 6). A
total of 38 tope sharks were captured across 13 of the 22 survey years
in the Alboran Sea (GSA 1); no tope sharks were captured in GSA 5 or
GSA 6. Previously, Mu[ntilde]oz-Ch[aacute]puli (1984) had reported
that, in 1981, in 95 commercial longline sets and 81 commercial trawls
in the western Alboran Sea, a total of 34 male and 3 female tope sharks
were recorded as captured off the southern coast of Spain, and 9 males
and 2 females were recorded as being captured off the coast of northern
Morocco. At the time of their study, Mu[ntilde]oz-Ch[aacute]puli (1984)
also described G. galeus as a species that was very often caught by
hook-and-line gear. Although the differences in gear types and fishing
effort prevent a direct comparison of the MEDITS data to the data
provided by Mu[ntilde]oz-Ch[aacute]puli (1984), the apparent decline in
captures of tope shark between these two datasets may indicate an
abundance decline in the Alboran Sea area.
No tope sharks were observed in the MEDITS trawl surveys conducted
around Sardinia (GSA 11) from 1994 to 2015 (Marongiu et al. 2017,
Ram[iacute]rez-Amaro 2017). Tope sharks were also not observed in
MEDITS surveys conducted from 1994 to 2009 in the northern Tyrrhenian
Sea (GSA 9), south of Sicily (GSA 16), in the Adriatic Sea (GSA 17,
18), or in the western Ionian Sea (GSA 19) (Relini et al. 2010). Two
individuals were captured in the southern Tyrrhenian Sea (GSA 10)
during this period--one in 1995 and one in 2001 (Relini et al. 2010).
Follesa et al. (2019) provided MEDITS data for the period 2012-2015 for
GSA 1, 5-11, 16-20, 22, 23, and 25. Tope sharks were captured only in
GSA 16 (south of Sicily) during this period, but at very low frequency
(0.5 percent of hauls in 200-800 m depth strata). No tope sharks were
observed in MEDITS surveys in GSA 16 from 1994 to 2012 (Geraci et al.
2017).
Additional information on the general distribution and abundance of
tope sharks comes from an international, standardized assessment of
shark bycatch rates in commercial swordfish and tuna longline fisheries
across nine regions of the Mediterranean Sea conducted during 1998-
1999. Tope sharks were captured in 6 of the 9 regions, with highest
catches occurring in the 3 westernmost regions: the Alboran Sea (n = 10
sharks/1,391 longline sets), the Balearic Islands (n = 4 sharks/1,379
longline sets), and the Catalan region (n = 2 sharks/331 longline sets)
(Megalofonou et al. 2005). A single tope shark was also reported in
each of 3 other regions where reported fishing effort was much lower:
the Straits of Sicily, the Aegean Sea, and the Levantine basin (32,
141, and 218 longline sets, respectively). Catch rates (expressed as
number of fish/1,000 hooks) were low across all areas, with the highest
catch rates occurring in the Levantine basin (0.143) and Aegean Sea
(0.057). The species was not observed in the Adriatic Sea (777 longline
sets), the Ionian Sea (833 longline sets), or the Tyrrhenian Sea (9
longline sets) (Megalofonou et al. 2005). Authors note that this may
indicate low or depressed abundances and/or low capture efficiency of
the gear used (Megalofonou et al. 2005).
The above data contrasts with landings of tope sharks reported to
International Commission on the Conservation of Atlantic Tunas (ICCAT)
by T[uuml]rkiye averaging 565 metric tons (mt) per year (ranging from
413 mt to 668 mt) from 2004 to 2009 in their shark longline fishery
(<a href="https://www.iccat.int/en/accesingdb.html">https://www.iccat.int/en/accesingdb.html</a>, accessed on June 27, 2024).
The large difference between the ICCAT data and the tope shark landings
reported by Megalofonou et al. (2005) may be explained by the fact that
the catches reported to ICCAT by T[uuml]rkiye came from the longline
fishery specifically targeting sharks. No tope shark landings, which
are reported voluntarily, were reported by T[uuml]rkiye after 2009. We
also note that no tope shark landings data for T[uuml]rkiye are
included in available FAO data (<a href="https://www.fao.org/fishery/statistics-query/en/capture">https://www.fao.org/fishery/statistics-query/en/capture</a>), which creates significant uncertainty regarding the
reliability of the available data. The only other Mediterranean
landings data in the ICCAT database are for France, which reported
landing 5 mt by trawl in 2010, and Morocco, which reported landing 6 mt
in 2011, 2 mt in 2012, and 4 mt in 2013 by handline, longline, and
purse seine.
Some available evidence suggests a decline in tope shark abundance
within the western Mediterranean. In 2016-2017, a group of 42 bottom
trawl, bottom longline, and drifting longline fishermen who were
interviewed in Costa Brava, Spain (coastal Catalan region) generally
considered tope shark populations to be declining locally, although the
statistical distribution of answers was not significantly different
than that expected by chance (Nuez et al. 2021). Around this same time
period, in 2015, the government of the Balearic Islands classified the
species as ``critically endangered'' in local waters using the IUCN Red
List criteria, stating that it had ``gone from being frequent in shops
and markets to being rare, with a sharp decrease in catches'' (Grau et
al. 2015). The critically endangered classification is described as
being based on direct observations and actual or potential exploitation
levels indicating a reduction in biomass of at least 80 percent in the
last ten years or in three generations of the species, and that the
reduction and its causes had not ceased, or are not understood, or are
not reversible (Grau et al. 2015). It is not clear, however, what data
were used in support of the observed decline. Additionally, a
historical abundance decline in the northern Tyrrhenian Sea over the
years 1898-1922 is indicated by Ferretti et al. (2005)'s analysis of
commercial landings data for fish ``traps'' targeting Atlantic bluefin
tuna: large declines (>90 percent) were observed for all sharks species
over this 25-year period, with tope sharks estimated to have declined
by 99.97 percent (95 percent CI: over 99.99 percent to 99.38 percent).
While Ferretti et al. (2005) do not discuss taxonomic or reporting
issues for tope sharks in the data, given the documented issues with
species-specific landings records in this region, confidence in the
historical landings records used in the study is somewhat limited.
G. galeus is also known to occur along the coast of Algeria and
Tunisia, in some cases arriving after long-distance migrations from the
North Atlantic (Holden and Horrod 1979, Fitzmaurice et al. 2003).
Capap[eacute] et al. (2005) noted that, at the time of their study,
tope sharks were the most ``abundantly and regularly'' landed shark
species off the coast of Algeria, and that tope sharks

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were also being captured off the coast of Tunisia, where it was later
referred to as ``quite common'' by Ragonese et al. (2013). Likewise,
Brada[iuml] et al. (2006) described the Gulf of Gab[egrave]s as an area
where tope sharks are ``regularly observed.'' As part of a population
genetics study, Thorburn (2015) was able to acquire 28 samples of G.
galeus from sport fishers and fish markets along the Algerian coast in
2009-2013, indicating that the species was still encountered in local
waters at that time. We are not aware of any additional data or surveys
that have been conducted along the southern margin of the Mediterranean
Sea that would aid in characterizing the species' relative abundance or
abundance trends.
In a relatively recent review of published literature and existing
databases, tope sharks were categorized as rare in the western,
central, and eastern Mediterranean and Adriatic Sea, and as having a
declining probability of occurrence (Serena et al. 2020). This study
involved a comprehensive review of available data and reports for both
European Union (EU) and non-EU countries bordering the Mediterranean,
and examined both fisheries-independent data (e.g., MEDITS) and
landings data from industrial and small-scale fisheries. When
considered collectively, this recent review, and other evidence (e.g.,
Ferretti et al. 2005) suggest that tope sharks may have undergone a
substantial decline in abundance within the Mediterranean.
No assessments of abundance trends are available for the eastern
central Atlantic.
In sum, population trends and abundance of tope sharks within the
NE Atlantic region remain poorly understood. Quantitative assessments
of tope shark abundance in the NE Atlantic region suffer from various
design and sampling flaws or errors, preventing us from drawing strong
conclusions about population trends. Overall, however, data from the
individual systematic surveys of the North Sea, Celtic Seas, English
Channel, and Biscay Bay do not indicate that the NE Atlantic tope shark
population has changed significantly over the respective data
collection periods. Systematic surveys around the Azores also provide
no evidence of a decline in abundance of tope sharks. Tope sharks are
relatively rare in the Mediterranean, and available evidence suggests a
large historical decline in abundance in this subregion. While the most
recent IUCN assessment (i.e., Walker et al. 2020) projects a declining
trend overall for tope sharks in the NE Atlantic, the high level of
uncertainty associated with this projection weakens confidence in this
result.
So. Africa
There are two main studies that characterize G. galeus population
abundance and trends in the So. Africa region. Both studies are focused
on the waters around South Africa, which is the core of the species'
distribution here. First, Best et al. (2013) compiled landings and
observation data from a wide array of sources to assess the status and
long-term population trends of the major chondrichthyan species in
False Bay, as well as their vulnerability to extinction. The data
sources included historical trawl and beach-seine scientific surveys,
commercial trawl, demersal shark longline, linefish, and beach-seine
catch returns, recreational shore-angling records, underwater
observations, spearfishing competition records, and rotenone surveys.
These datasets cover various time periods that collectively span 1897
to 2011, and the authors note that the quality and quantity of the data
varied considerably, preventing them from using a consistent protocol
to analyze the datasets together. Of the 37 chondrichthyan species
documented in the combined dataset, G. galeus was the most commonly
encountered species, with over twice as many records as the second-most
commonly recorded species, M. mustelus (Best et al. 2013). It was also
the only species for which multiple data sources consistently indicated
a statistically significant decline in abundance based on rank
correlation analysis. This analysis used CPUE estimates based on catch
and effort data from the commercial beach seine, recreational shore-
angling, and demersal longline datasets, which collectively spanned the
years 1969 to 2011. However, it is important to note that the
recreational shore-angling fishery began on the eastern and western
shores of the bay, which are adjacent to the deeper-water habitats
where tope sharks may be found, but has since moved to shallower, more
accessible sandy beach areas, where tope sharks do not typically
reside. Thus, the declining trend in G. galeus CPUE based on the
recreational shore-angling dataset may in part be attributable to this
evolution of the fishery.
More recently, Winker et al. (2019) also used a combination of
datasets, including fisheries catch data and fishery-independent survey
data, to estimate the population trend and stock status for tope sharks
throughout South African waters more broadly. Using JARA, an abundance
trend for tope sharks was estimated based on a fishery-independent
demersal trawl survey conducted along the south coast of South Africa
roughly every autumn and spring from 1991 to 2016. Tope shark abundance
was found to have steadily declined at an average rate of approximately
-2.7 percent per year from 1991 to 2016, yielding an estimated
population decline of -50.9 percent over the full survey period (Winker
et al. 2019). Winker et al. (2019) then used this procedure to project
the population trend over three generation lengths (~69 years, based on
an estimated generation length of 23.1 years) beginning in 1991. This
analysis predicted a total population decline of -85.1 percent by the
year 2060, compared to 1991, though the 95 percent confidence interval
around this estimate is very wide, spanning a range of possibility that
includes a stable population trend and even slight population growth
(Winker et al. 2019).
In addition to estimating the abundance trend from the demersal
trawl survey, Winker et al. (2019) also evaluated the status of the G.
galeus fishery stock in South Africa relative to estimated harvest
levels using the JABBA modeling procedure. Inputs to this analysis
included the abundance index derived for the JARA analysis described
above and an aggregated time series using data from the aforementioned
demersal trawl survey (1992-2016), commercial linefish catch reported
in South Africa's National Marine Linefish System (NMLS) database
(1990-2016), catch data from the Department of Agriculture, Forestry,
and Fisheries demersal shark longline database (1992-2016), and
historical catch reconstructed from shark dealer sales in Gansbaai
(described as the center of the South African shark fishery in the
1950s) (1952-1989). It is worth noting that the authors relied on
several assumptions to address various uncertainties in these datasets,
and these may have influenced the results of the analysis to some
degree. For the demersal trawl and linefish datasets, for example, a
portion of the shark catch was not reported to the species level. In
order to include this portion of the catch in their analysis, the
authors used two slightly different approaches to estimate the
proportion of G. galeus in the unidentified portion of the two
datasets. Each applied a conversion function that was based on the
proportion of G. galeus observed in the species-specific portion of the
shark catch. Additionally, for the linefish dataset, to estimate the
historical catch before the beginning of official reporting to South
Africa's

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NMLS database (i.e., before 1990), the authors relied on shark dealer
sales from the Gansbaai fishing port, which they scaled up by a factor
of 1.54 to account for catches from other regions. This value was based
on the ratio of total catch reported in Gansbaai compared to total
catch in the NMLS database in the year 1987. It is not clear how
potential inaccuracies in these assumptions may have affected the
downstream modeling results, so the conclusions of this analysis should
be interpreted with caution. Commercial catch of G. galeus was found to
have declined substantially from 1952 to 2016, corresponding to a
predicted decline in population biomass that largely matched the
results of the JARA analysis. Model estimates from four modeling
scenarios indicated that biomass of the G. galeus population in South
Africa has declined from approximately 93-94 percent of carrying
capacity in 1952 to 10-14 percent of carrying capacity in 2016, and
that there is a greater than 97.5 percent likelihood that if catch of
G. galeus continues at its catch rate at the time (~329 mt per year),
commercial extinction of the species in South Africa (i.e., when
biomass reaches a point where fishing the species is not commercially
viable) would occur by 2055 (Winker et al. 2019). According to Winker
et al. (2019), the harvest rate must be reduced to less than 100 mt per
year in order to reverse the declining trend and allow for positive
population growth.
We did not find any information on population abundance or trends
from other parts of the region outside of South Africa, such as along
the southwestern African coast where the species is also thought to
occur.
In sum, the best available information indicates that abundance of
G. galeus has declined significantly in South Africa, which is the core
of its distribution in this region, since the mid-20th century. An
analysis of multiple fisheries datasets (e.g., recreational angling,
demersal longline, and beach seine fisheries) indicates that G. galeus
was the most commonly encountered chondrichthyan species in the region
from 1969 to 2011, but underwent a ``dramatic and consistent''
population decline (Best et al. 2013). This decline was attributed to
the species' long history of commercial exploitation in the region,
exacerbated by its low biological resilience to such exploitation (Best
et al. 2013). A broader analysis using several, novel modeling
approaches, indicates that G. galeus has likely experienced
unsustainable fishing pressure since at least the 1950s and that
current population biomass is estimated to be less than 15 percent of
the population's carrying capacity (Winker et al. 2019). Model
projections suggest that fishing pressure must be significantly reduced
(by over 60 percent) for the species to begin to rebound. Together,
these studies indicate a major long-term reduction in G. galeus
abundance in So. Africa caused by past and ongoing fishing pressure.
SW Atlantic
There have not been any formal assessments of tope shark abundance
in the SW Atlantic region. However, several fisheries-derived CPUE
datasets, anecdotal accounts from regional experts, and reported
changes in local fishing strategies indicate, in aggregate, that the
tope shark population in the SW Atlantic has declined significantly
since the peak of fishing effort in the 1980s and 1990s.
A 24-year CPUE dataset from the demersal trawling fleet in
Argentina provides some indication of the G. galeus population trend
from 1992 to 2015 (Chiaramonte unpublished 2019, cited in Walker et al.
2020). Based on this relative abundance index, tope shark abundance
declined significantly from 1992 to 2000 and remained at this reduced
level until the end of the dataset (Walker et al. 2020). Using JARA,
Walker et al. (2020) estimated an annual rate of population reduction
of -5.9 percent, consistent with an estimated median reduction of -99.3
percent over three generation lengths (79 years). It is worth
highlighting that CPUE in this study was calculated in terms of
kilogram (kg) per trip, so the dataset does not account for variations
in fishing effort between trips.
Lucifora (2003) designed a matrix-based population model to
describe the baseline demographics of tope sharks in the Bah[iacute]a
Anegada region in Buenos Aires Province, Argentina. The model was also
used to simulate population trends under several hypothetical scenarios
based on existing fishing conditions at the time and potential
alternative scenarios. Lucifora (2003) found that the predicted
population trend was negative for all scenarios that simulated the
possible fishing conditions at the time. The scenario that best
represented the existing conditions in Bah[iacute]a Anegada based on
the author's knowledge of the fishery (i.e., fishing for both adults
and large juveniles) yielded a projected rate of population decline
between -6.7 and -12.8 percent annually. Notably, this model-based
estimate roughly reflects the average rate of population decline
derived from the 24-year CPUE dataset discussed above (-5.9 percent;
Walker et al. 2020).
Chiaramonte (1998) provided an estimate of CPUE from the tope shark
gillnet fishery in Necochea from 1990 to 1996, which the author
described as ``the most important directed shark fishery in the South-
West Atlantic.'' CPUE fluctuated significantly during this period
without any discernible trend. Moreover, the author noted that changes
to certain features of the fishery during the study period, such as to
the gear and fishing effort, limit the reliability of this CPUE
estimate as an indicator of tope shark abundance (Chiaramonte 1998).
A study by Villwock de Miranda and Vooren (2003) estimated CPUE in
Brazil's Rio Grande do Sul fishery in the period 1975-1997, basing
their estimates on the associated number of fishing trips for each of
the main gear types in which G. galeus is captured. While the study
differentiated landings by broad categories of sharks rather than by
species, varying seasonality of landings from each of the five gear
types was used as a reasonable indication of the species that are
likely represented by the CPUE estimates for each fishery. For example,
the authors note that until 1988, the majority of
``ca[ccedil][atilde]o'' landings came from the simple trawl fishery, of
which approximately 81 percent was caught during the winter months from
May to October. Given the winter residency of G. galeus and M. schmitti
in this region, the authors assumed that simple trawl CPUE estimates
generally reflected the combined abundance of these two species.
Overall, CPUE estimates of both the simple and pair trawl fisheries
show a similar pattern of severe decline following a peak in landings
in the mid-1980s. Simple trawl CPUE increased from 1975 to 1987, which
the authors interpreted as reflecting a shift in the fishery from
targeting primarily G. galeus in earlier years to increasingly
retaining M. schmitti as well. In the ensuing years, simple trawl CPUE
declined dramatically and from 1992 to 1997 averaged approximately 20
percent of its peak level in 1985-1987. As oceanic bottom gillnets
gradually replaced trawls as the principal gear type for capturing
``ca[ccedil][atilde]o'' in the early 1990s, oceanic gillnet CPUE
estimates were nearly ten times greater than those of the simple trawl
fishery. However, Villwock de Miranda and Vooren (2003) cautioned that
the two datasets were not directly comparable, because the oceanic
gillnet fishery specifically targeted ``ca[ccedil][otilde]es,''
operated in areas inaccessible to trawls, and used more effective gear
than trawling--extensive

[[Page 20270]]

nets whose effort was not captured by the simplified count of vessel
trips. CPUE increased during the 5 years in which oceanic gillnet CPUE
estimates were available (1993-1997), contradicting the trend in simple
trawl CPUE. However, because the index of fishing effort used in this
study (i.e., vessel trips) does not account for possible changes in the
length, duration, or mesh size of gillnets deployed, it is uncertain to
what extent oceanic gillnet CPUE accurately reflects the abundance of
G. galeus and M. schmitti. It is perhaps more notable that CPUE
estimates of both the simple and pair trawl fisheries, while likely
representing different shark species, show a similar pattern of severe
decline following a peak in landings in the mid-1980s. These datasets
suggest a broader collapse of elasmobranch fisheries in southern Brazil
during this time.
There are also several anecdotal reports of fishery collapse and
changes in fishermen behavior to adapt to the declining populations
(Chiaramonte 1998; Barbini et al. 2015; Irigoyen and Trobbiani 2016).
For example, Chiaramonte (1998) noted that in the late 1990s, Necochea-
based trawlers were forced to set gillnets further from the coast due
to declining yields near shore. The fishermen allegedly attributed this
to a movement of the tope shark population away from shore, but the
author suggested that it was more likely an indication of declining
abundance (Chiaramonte (1998)).
Taken together, the data described above show a generally
consistent pattern of tope shark population decline in the 1990s
resulting from intensive historical fisheries in the region. The best
scientific and commercial information available provide no indication
that the population has rebounded since falling to its lowest levels on
record in the 1990s and early 2000s.
NE Pacific
Based on catch data in California from 1938 to 1944 (Ripley 1946),
Holden (1977) roughly estimated an unexploited population size for the
tope shark of 29,600 tons (~26,853 mt) (6.7 x 10\5\ mature females).
However, following the intensive fishery for G. galeus in the 1940s and
1950s, there appear to have been no other estimates of population size
that could be compared to this baseline. Similar to other regions, we
must instead rely on various qualitative accounts of the fishery, as
well as sporadic catch data from fishery-independent and fishery-
dependent sources gathered in the decades since to estimate relative
population trends.
As fishing pressure rapidly intensified in the late 1930s and
1940s, sufficient resources were not available to quickly establish a
system of fishing logs or thoroughly conduct interviews with the
fishers at landing sites (Ripley 1946). However, available accounts
from the time identified early signs of population depletion based on
observations of the underlying fishery dynamics. Following the peak of
the fishery in 1938-1939, when total shark landings in California
ballooned by over tenfold to more than 4,000 mt per year, Ripley (1946)
observed that landings began to decrease significantly despite
increasing fishing effort. Comparing the December, January, and
February landings of tope shark livers at the port of Seattle from 1943
to 1944, the FWS noted a 63 percent, 20 percent, and 70 percent
decrease, respectively, despite observing that ``fishermen had
intensified their efforts and were using more gear'' (FWS, April 10,
1944).
Ripley (1946) provided quantitative estimates of the tope shark
population trend in this region based on CPUE in the gillnet fishery.
Effort data was based on interviews with gillnet fishers in four
regions spanning the coast of California and consisted of boat records
from 489 fishing trips between 1942 and 1945. Dividing into the total
number of tope sharks caught yielded a rough estimate of the average
number of sharks taken by 1,000 fathoms (~1.8 km) of net fished for 20
hours. The data show a declining trend in CPUE for all four ports,
which is particularly evident in Eureka (northern California), where
data were collected for all 4 years. Ripley (1946) warned of several
limitations with the data, including the relatively small sample size
and inconsistency in the timing of the interviews with respect to the
seasonal peak of the fishery (see also Roedel and Ripley 1950).
However, he found ``little doubt'' that fishing success had declined
from 1942-1943 to 1944-1945 and suggested that the trend observed in
Eureka was likely representative of the tope shark population along the
entire California coast (Ripley 1946).
Two years later, Barraclough (1948) reported a similar trend in
British Columbia, with landings of tope shark livers rapidly declining
from a peak of 27.9 mt in 1944 to 4.1 mt in 1946, concurrent with
marked declines in two rough estimates of CPUE: (1) the average monthly
catch of tope shark livers per boat, and (2) the average monthly catch
per fishing trip per boat. Data were collected from the sunken gillnet
fishery in Hecate Strait, and both metrics indicated a sharp decline
from 1943 to 1946.
Landings continued to decline through the end of the 1940s, largely
due to reduced fishing yields from the depleted tope shark population,
but also in part due to the re-opening of international markets for
other vitamin-bearing fish oils after the end of World War II, as well
as the development of synthetic vitamin A alternatives, which
substantially lowered demand (Roedel and Ripley 1950). As the fishery
tailed off, species-specific data collection for G. galeus was largely
discontinued. The State of California returned to the practice of
reporting shark landings in aggregate until 1978, and while there are
sporadic landings data for G. galeus in Oregon and Washington in the
1950s and 1960s (NMFS Office of Science and Technology), there is no
information on fishing effort to accurately assess the species'
relative abundance during this period.
Beginning in the late 1970s and 1980s, various Federal, State, and
international monitoring programs were established to more thoroughly
assess NE Pacific fisheries. Several of the resulting datasets include
G. galeus catch statistics, which can be used to estimate more recent
population trends. The West Coast Groundfish Bottom Trawl Survey began
in 1977 and was streamlined in 2003 to conduct surveys annually from
May to October along the U.S. West Coast. Generally, tope shark
encounters in this survey have been quite rare, with eight being the
most individuals recorded in a single year. The species is most
commonly encountered in central California. There is some indication
that catch rate increased briefly in this region in 2016-2018; however,
after a suspension of the survey in 2019 and 2020, catch rate returned
to relatively low levels in 2021-2023.
The International Pacific Halibut Commission (IPHC) conducts a
Fisheries-Independent Setline Survey (FISS) to monitor halibut stocks
in the NE Pacific. The FISS is conducted annually from May to September
using bottom-set longline gear and covers a random subset of 1,890
sampling stations ranging primarily from northern California to the
Bering Sea. The survey includes bycatch data starting in 1998 collected
using two different sampling protocols: vessels counting bycatch for
the whole longline haul and vessels counting bycatch on only the first
20 hooks of each 100-hook skate. Both subsets of data show tope shark
CPUE to be highly variable over time. To assess population trend, the
Committee on the Status of Endangered Wildlife in Canada (COSEWIC)
applied a pair of generalized linear models (GLM) to each

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portion of the data. They found that the mean number of tope sharks
caught per sampling station did not change from 1998 to 2002 but then
increased significantly from 2003 to 2018 (COSEWIC 2021). They also
highlighted that tope shark observations have particularly increased in
the waters east of Haida Gwaii, British Columbia. According to COSEWIC,
the species was not recorded in this area between 1996 and 2005,
despite substantial fishing effort (7,243 hours of trawl and 1,632 sets
with hook and line gear) (COSEWIC 2021). However, since 2005, 295 tope
sharks have been recorded by the FISS in this area. This is notable, as
the area was heavily fished during the peak of the Canadian tope shark
fishery in the 1940s, suggesting that population abundance in this
region was once quite high (Barraclough 1948).
To expand the COSEWIC modeling analysis and incorporate the years
since 2018, we applied a similar approach to assess population trend
but modified the model framework in a few ways. For detailed
information on model inputs, please see the Status Review Report. Model
predictions indicate that population abundance has generally increased
over the study period. The positive trend is consistent regardless of
the method of model prediction. Moreover, the population trend varies
according to latitude, corroborating the earlier observation by COSEWIC
(2021). By plotting the modeled trend against Latitude along the x-
axis, it is clear that the population trend is significantly greater at
higher latitudes. There is also some indication that the population may
be slightly declining in the middle of the survey distribution
(~45[deg] N). COSEWIC (2021) suggested that the disproportionate
increase in British Columbia might reflect a northward movement of the
population in response to warming waters. However, the history of this
area as a prime fishing ground for tope sharks in the 1940s suggests
that the species once occupied the area in great numbers. Therefore, we
find it equally possible that the increase in CPUE is indicative of
population growth.
Since 2002, tope sharks have also been recorded as a bycatch
species in two fisheries observer programs that are jointly
administered by NMFS and the Pacific States Marine Fisheries
Commission. The West Coast Groundfish Observer Program (WCGOP) monitors
at-sea bycatch discard rates for many of the commercial groundfish
fishery sectors along the U.S. West Coast, including the Federally-
managed limited-entry trawl fishery, several State-managed trawl
fisheries, as well as various nearshore and pelagic fixed gear
fisheries (e.g., longlines, hand lines, fish pots/traps) (see Northwest
Fisheries Science Center (NWFSC) 2024a for more information). The At-
Sea Hake Observer Program (A-SHOP) monitors discard rates for the three
components of the at-sea midwater trawl fishery targeting Pacific hake
(whiting): the Mothership, Catcher-Processor, and Tribal sectors (see
NWFSC (2024b) for more information). Both datasets provide limited
insight into tope shark population trends, as discards are sporadic for
most gear types. However, there is some indication in the bottom and
midwater trawl fisheries, where tope sharks are most commonly
encountered, that discard rate has generally increased since 2015
following a low period in the early 2010s. The trend is particularly
apparent in the at-sea Pacific hake fishery north of 46.25[deg] N
(i.e., waters off the coast of Washington). The WCGOP also records
landings statistics for bycatch species, which combined with observed
discards provides a rough estimate of total catch rate since 2002.
Here, CPUE is calculated in terms of the total tope shark catch (i.e.,
landed plus discarded weight) per vessel for each type of fishing gear.
Tope sharks are encountered relatively infrequently in Oregon and
Washington, mainly in the midwater trawl fisheries, and there is no
discernible trend in CPUE. In California, similar to the discards-only
data, total catch per vessel has generally increased since 2015 for
each gear type where tope sharks are consistently encountered (i.e.,
bottom trawl, bottom/midwater trawl, fixed gear, and non-trawl net gear
fisheries). For vessels using non-trawl net gear in California, CPUE
declined substantially from an average of 8.9 x 10-2 mt per
vessel per year in 2002-2006 to 9.1 x 10-4 mt per vessel in
2013, before increasing again in subsequent years.
Logbook data from the State-managed gillnet fishery in California
indicate that CPUE in the California gillnet fishery fluctuated around
0.5 individuals caught per vessel trip from 1981 to 2006. Based on the
reported net length and soak time for each vessel trip where a tope
shark was caught, we can roughly compare this value to the estimates
reported by Ripley (1946). Average net length and soak time per vessel
trip in the logbook dataset are approximately 603.3 fathoms (~1.1 km)
and 29.5 hours, respectively. Thus, scaling to the unit of CPUE used by
Ripley (1946), 0.5 individuals caught per vessel trip is roughly
equivalent to 0.6 individuals caught in 1,000 fathoms (~1.8 km) of
gillnet fished for 20 hours. That is approximately a 15- to 100-fold
decrease in CPUE from 1942 to 1981-2021. It is important to note that
the California Department of Fish and Wildlife (CDFW) cautions against
using set-specific features (e.g., net length, soak time) as the basis
for CPUE calculations; however, broadly summarizing the data as above
provides a rough indication of the scale of population reduction since
the peak of the fishery in the early 1940s. From 2006 to 2013, CPUE
declined substantially from 0.48 to 0.02 tope sharks caught per vessel
trip and then generally increased from 2015 to 2021. Notably, by
dividing the logbook dataset by month, it is clear that the annual CPUE
during warmer months (May-August) declined significantly in 2008 and
has remained relatively low in the years since, rebounding only
slightly in recent years. By contrast, CPUE during cooler months
(October-November) has increased substantially in 2018-2021 compared to
prior years. The trends in CPUE, however, take place alongside several
regulatory changes, which have gradually constrained the effort and
location of gillnet fishing in California since the 1980s. This
includes a series of depth- and area-based gillnet bans throughout
central California in the late 1980s and 1990s (Forney et al. 2001), a
1994 ban on gillnet fishing within 3 nautical miles (nm) of the
California mainland and within 1 nm of the Channel Islands (CA
Proposition 132), an emergency gillnet closure in 2000 and 2001
limiting the fishery to Federal waters south of Point Conception, and a
permanent extension of the set gillnet ban in 2002 in all waters
offshore of central California (from Point Reyes to Point Arguello)
less than 60 fathoms (110 m) in depth (California Code of Regulations,
Title 14, Section 104.1). As a result, the total effort in the
California gillnet fishery has drastically declined since 1986, as
gillnet fishing has largely been restricted to offshore waters in
southern California. As discussed in Range, Distribution, and Habitat
Use, tope sharks tend to migrate seasonally toward the poles in the
summer and toward the equator or into deeper, offshore waters in the
winter. Thus, the disproportionate increase in winter CPUE, as compared
to summer CPUE, in recent years may be related to the concentration of
gillnet fishing effort in the southern, offshore portion of the
species' distribution in this region.
Since 1980, tope sharks have also been recorded by California
commercial passenger vessel (CPFV) (i.e., charter fishing) operators,
who submit

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mandatory logbooks to CDFW. Tope sharks have been reported only
sporadically in northern California. In central and southern
California, the species is encountered more consistently; however,
there is not a clear long-term trend in CPUE, as it has fluctuated on
an approximately 15-year frequency in both regions. Peaks in CPUE in
the mid-1980s, around 2000 (in central California) or 2008 (in southern
California), and in the mid-2010s are separated by periods of lower
CPUE in intervening years. In both regions, CPUE peaked most recently
in 2016 but has generally declined in the years since.
In sum, following the collapse of the North American tope shark
fishery in the 1940s, observations of the species have been relatively
rare in the NE Pacific. Throughout the majority of the last 4 decades,
the species has been only sporadically encountered in the wide-ranging
West Coast Groundfish Bottom Trawl Survey and by NMFS observers in
various Federal and State-managed fisheries. In the California gillnet
fishery, a rough comparison between the data presented by Ripley (1946)
and logbook data from 1981-2021 reveals that tope shark CPUE is
approximately 15- to 100-fold lower than it was during the peak of the
fishery in the 1940s. However, it must be noted that the effort and
location of the fishery has changed dramatically since the 1940s, which
may skew recent estimates of CPUE. Two fisheries-independent surveys
and several fisheries reporting databases provide insight into the
recent population trend in the NE Pacific. With the exception of the
CPFV logbooks, available datasets consistently show an increase in CPUE
since 2016. In several datasets, such as the WCGOP and A-SHOP discards,
and the California gillnet logbooks, this increase follows an inverse
period of decline in the early 2010s. Thus, the extent to which this
pattern may be part of a natural population cycle or may reflect
changes in fishing behavior is not clear. Data from the fishery-
independent IPHC FISS, which is the most statistically robust dataset
available, suggest that CPUE has significantly increased since 1998,
particularly in the northern portion of the species' distribution.
Thus, while the population remains depleted compared to its unexploited
level, there is consistency among datasets suggesting that the
population is likely increasing to some degree.
SW Pacific
In the SW Pacific, tope shark populations in Australia and New
Zealand are monitored and managed independently. Although tagging and
genetic data indicate that some migration and interbreeding occurs
between the two regions (see Population Structure), the rarity of
trans-Tasman recaptures in tagging studies and the substantial
geographic separation suggest that such movements are fairly
infrequent. Most animals tend to stay within a home range of less than
500 km, in close proximity to local pupping and nursery areas (Hurst et
al. 1999; Walker et al. 2020). Accordingly, given the separate
management of tope sharks in Australia and New Zealand, available
information on abundance and population trends is presented separately
for the two countries.
Sustained harvest of tope sharks in Australia since the early 20th
century has driven a significant long-term decline in population
abundance (Davis et al. 2024). Early signs of overexploitation date
back to the 1940s, when both large, gravid female and juvenile tope
sharks were heavily targeted in inshore nursery areas of southern
Australia and Tasmania (Olsen 1959; Olsen 1984; Fowler et al. 2005).
Olsen (1959) reported declining juvenile abundance in two Tasmanian
nurseries, which he attributed to the intense fishing pressure on both
juveniles and gravid females during their pupping migration (see also
Olsen 1984). He reported a sharp increase in fishing effort between
1944 and 1956 alongside a concurrent decline in mean body size and
CPUE, warning that the fishery was showing ``trends which are
suggestive of depletion'' and may follow the patterns of collapse
observed in the NE Pacific unless stronger regulations were put in
place (Olsen 1959). In 1991-1997, Stevens and West (1997) resurveyed
several nursery areas in Tasmania and Victoria that were originally
identified by Olsen. They found that catch rates were ``much lower'' at
all sites and that pups may no longer be present at certain sites where
they were once fairly common, such as in Georges Bay and
D'Entrecasteaux Channel (Stevens and West 1997). During Olsen's
original tagging program from 1947-1956, only 0.3 percent of the 1,170
juveniles tagged in Pittwater were recaptured at the same site. Stevens
and West (1997) conducted a similar tag-recapture experiment in Upper
Pittwater in 1996, and 18 percent of the 100 tagged juveniles were
recaptured at the same site, a nearly 60-fold higher recapture rate.
The authors interpreted this result as indication of reduced population
abundance, although differences in site fidelity or dispersal behavior
might also have played a role. While Olsen (1984) reportedly caught up
to 80 juveniles per day in Pittwater by handline in the 1940s-1950s,
Stevens and West (1997) were not able to catch a single tope shark in
23 hours of fishing in 1992 using the same methods and gear. Likewise,
in Port Phillip Bay, Victoria, where Olsen could reportedly catch more
than 200 juveniles and subadults per day in 1947-1951 (pers. comm.,
cited in Walker 1998), artisanal fishers caught fewer than 10 per day
during a 3-year research study in the 1990s (Walker 1998). Moreover,
demersal gillnet and longline surveys conducted in Bass Strait showed
an 87 percent reduction in CPUE between 1973-1976 and 1998-2001 (Walker
et al. 2005).
In response to the observed population declines, the Australian
government listed the tope shark as ``conservation dependent'' under
the Environment Protection and Biodiversity Conservation (EPBC) Act in
2009. A formal Rebuilding Strategy was introduced in 2008 and updated
in 2015. This strategy set a target to rebuild the stock to the limit
reference point (B<INF>20</INF>) within three generations (66 years)
from 2008 (Davis et al. 2024). Despite these measures, subsequent
assessments have consistently shown that the population in Australia
remains overfished (Davis et al. 2024). One of the earliest formal
stock assessments for the Australian tope shark fishery was developed
by Punt and Walker (1998). Based on a spatially aggregated, age- and
sex-structured model, estimates of adult biomass at the start of 1995
ranged from 13 percent to 45 percent of pre-exploitation levels,
depending on model specifications. Punt et al. (2000a) suggested that
age-1+ biomass (B<INF>1+</INF>) at the start of 1997 was likely between
17 percent and 25 percent of pre-exploitation levels, while pup
production was likely between 12 percent and 18 percent of pre-
exploitation levels (discounting model scenarios that the authors
deemed unrealistic). Thomson and Punt (2009) later updated the
assessment model by incorporating fisheries-independent data from
gillnet research surveys conducted between 1973 and 2008, along with
several fisheries-dependent datasets. Model estimates suggested that
B<INF>1+</INF> at the start of 2007 ranged from 7 percent to 20 percent
of pre-exploitation levels, while estimates of pup production ranged
from 6 percent to 17 percent of pre-exploitation levels (Thomson and
Punt 2010). Thomson and Punt (2009) found significant differences
between models that assumed a single fishery stock in Australia versus
those that assumed two. Specifically, the two-stock models

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consistently provided a better fit to the data and estimated less
depletion (B<INF>1+</INF>: 14-20 percent pre-exploitation; pup
production: 11-17 percent pre-exploitation) than one-stock models
(B<INF>1+</INF>: 7-9 percent pre-exploitation; pup production: 6-8
percent pre-exploitation).
In the past decade, fishery managers in Australia have transitioned
away from CPUE-based stock assessment models toward a new framework
based on close-kin mark-recapture (CKMR) analysis (Shark Resource
Assessment Group (SharkRAG) 2011; Davis et al. 2024). To apply the CKMR
framework to the Australian tope shark population, Thomson et al.
(2020) collected and genotyped over 2,400 individuals from across South
Australia, Bass Strait, and Tasmania between 2010 and 2017. Their
analysis yielded an estimate of approximately 50,000 mature individuals
in the population in the early 2000s (Thomson et al. 2020). This figure
was three to four times lower than the abundance estimated by the
conventional stock assessment model (Thomson 2012). Thomson et al.
(2020) suggest that there are likely multiple overlapping biological
stocks of tope sharks in Australia, perhaps structured according to
different pupping grounds, which are differentially depleted (Thomson
et al. 2020). They also interpret the relatively small abundance
estimate from the CKMR analysis as evidence that the immigration rate
from the considerably larger tope shark population in New Zealand is
limited and likely does not significantly influence local demographics;
although Walker et al. (2020) suggested that migration from New Zealand
may have helped stabilize the Australian population since the early
2000s.
Thomson et al. (2020) also generated projected population trends to
the year 2037 by testing four rates of constant exploitation: zero
catch, the 2016 catch rate, the 2017 catch rate, and the mean catch
rate between 2013 and 2017. All four scenarios resulted in a modest
upward trend in adult abundance, with estimated annual increases of
approximately 1-11 percent depending on the exploitation scenario.
However, the confidence intervals were very wide, and a declining trend
could not be ruled out in any case. Based on the results of this
analysis, SharkRAG adopted a fishery management strategy based on the
mean 2013-17 catch rate scenario, which predicted a 3 percent average
annual increase in population abundance (Davis et al. 2024).
Recently, Thomson et al. (in prep) applied generalized linear
modelling to updated CKMR data with roughly 3,000 additional tope shark
samples collected between 2018 and 2023. Results of the modified GLM,
accounting for ageing error and the triennial female reproductive
cycle, indicate that adult abundance has increased approximately 7.5
percent (90 percent CI: 2.7 percent-12.3 percent) annually over the
period 2006-2020. According to the authors, these results confirm the
finding of Thomson et al. (2020) that tope sharks in the Southern and
Eastern Scalefish and Shark Fishery (SESSF) are recovering. A full age-
structured CKMR model, incorporating individual ageing error and
fecundity-at-size effects, is under development and will be presented
to SharkRAG in 2026.
Lastly, an analysis of CPUE in the trawl sector of the SESSF (1996-
2020) provides additional insight into recent population trends in
Australia. The data show a decline in catch rate from 1996 to 2003,
consistent with the datasets used by Thomson and Punt (2009). After
2003, however, catch rate has increased steadily, reaching a level in
2020 that approaches or slightly exceeds that of 1996. Notably, unlike
the gillnet fishery, where changes in fishing behavior towards greater
avoidance have undermined the reliability of CPUE datasets, the trawl
fishery is unlikely to have targeted tope sharks at any time and
therefore provides a more consistent record of catch and effort (Tuck
2022). But Davis et al. (2024) caution that the trawl fishery accounts
for only a small proportion of the total tope shark catch landed in
southern Australia, and generally operates in locations different from
those fished by the Gillnet, Hook, and Trap sector. Therefore, observed
CPUE trends may not be representative of the broader Australian
population.
There have been several efforts to establish a standardized CPUE
index to estimate a population trend throughout New Zealand using
available commercial fisheries data. The use of data from targeted set
gillnet and bottom longline fisheries resulted in unreliable abundance
indices due to sparse, inconsistent data and the potential for
hyperstability (when CPUE remains artificially high despite an
underlying decline in abundance, typically because fishers non-randomly
target dense aggregations of the population) (Bradford 2001). Analysis
of CPUE from bycatch fisheries by Ayers et al. (2006) revealed no
consistent nationwide abundance trend but suggested a possible
southward shift in distribution, possibly driven by warming sea
temperatures. More recently, Fisheries New Zealand evaluated relative
biomass indices in five spatial monitoring units that encompass the New
Zealand exclusive economic zone (Fisheries New Zealand 2024b). As with
the previous studies, although the tope shark population in New Zealand
is assumed to be connected, Fisheries New Zealand was not able to
establish a biomass index for the population as a whole. Therefore,
monitoring units were delineated using boundaries that roughly
correspond to gaps between where tope shark catch is concentrated (Dunn
and Bian 2018; see Figure 3-32 in the Status Review Report). The
biomass indices used in the assessments are based on CPUE data from
inshore research trawl surveys as well as commercial set gillnet,
bottom longline, and bottom trawl fisheries operating within each
monitoring unit (Tremblay-Boyer 2021). The Inshore Fisheries Working
Group (INSWG) determined which datasets to include in each regional
biomass index based on the amount of data available and whether or not
the data were judged to be reliable. Reference points (e.g., biomass at
MSY (B<INF>MSY</INF>), fishing mortality at MSY (F<INF>MSY</INF>)) for
relative biomass assessments were established for three of the five
monitoring units based on reference periods when the catch rate was
assumed to be sustainable. The INSWG then assigned qualitative
likelihood scores to evaluate the status of each regional stock with
respect to the reference points (i.e., ``Very Likely'': >90 percent
probability; ``Likely'': 60-90 percent probability; ``About as Likely
as Not'': 40-60 percent probability; ``Unlikely'': 10-40 percent
probability; ``Very Unlikely'': <10 percent probability) (Fisheries New
Zealand 2024b).
In the Far North region (N/1E), the biomass index derived from the
combined set gillnet, bottom longline, and bottom trawl CPUE series has
increased steadily since 1995, alongside an approximately 75 percent
decrease in fishing effort. The INSWG found it likely that current
biomass was at or above B<INF>MSY</INF>. They also found it unlikely
that biomass would decline at the current level of catch (Fisheries New
Zealand 2024b). In the eastern North Island region (2/3N), none of the
available CPUE data from set gillnet, bottom trawl, or bottom longline
fisheries were accepted by the INSWG as indicative of population
biomass, as there were conflicting trends in the data series that could
not be explained. Furthermore, while there is some indication from the
east coast South Island survey data that biomass was generally higher
after 2007 compared to pre-1996, the survey almost exclusively

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sampled juveniles and was therefore not considered as a suitable
biomass index (Fisheries New Zealand 2024b). In the Lower South Island
region (3S/5), the set gillnet CPUE dataset was accepted as a valid
biomass index. The INSWG found it very likely that overfishing is
occurring and about as likely as not that current catch levels will
cause biomass to decline below 50 percent of the target B<INF>MSY</INF>
baseline. As compared to a B<INF>MSY</INF>-compatible baseline
established based on a period of relatively stable catch rates between
1989 and 1999 (assuming that the stock was not in a depleted state
during this reference period), biomass has declined gradually as
fishing intensity has increased (Fisheries New Zealand 2024b). In the
Chatham Rise region (SCH 4), tope sharks are mainly caught in the
bottom longline fishery, which was the only fishery in the region with
sufficient data to be developed into a biomass index (Tremblay-Boyer
2021). Based on 16 years of available CPUE data, the biomass index has
fluctuated without a discernible trend since 2003-2004 alongside a
gradual increase in fishing intensity (Fisheries New Zealand 2024b).
Because the dataset is relatively short and does not show any clear
trends, the INSWG was not able to establish a reference baseline for
the biomass index in this region. In the West Coast region (7/8/1W),
the INSWG elected to use the WCSI research trawl survey, excluding the
Tasman Bay and Golden Bay region, as the primary index of biomass.
Based on this dataset, biomass declined from the late 1990s to 2000 and
has largely fluctuated without a discernible trend in the years since.
The INSWG established a target B<INF>MSY</INF> baseline as the mean
estimated biomass from 2005 to 2017, on the basis that biomass remained
stable during this period while fishing intensity was ``high and
relatively stable'' (Fisheries New Zealand 2024b). They concluded that
the stock was about as likely as not to be at or above this reference
baseline and about as likely as not to be experiencing overfishing at
current catch levels (Fisheries New Zealand 2024b).
In June 2018, Fisheries New Zealand conducted a qualitative risk
assessment for local chondrichthyan species, in accordance with the
objectives of the country's National Plan of Action for Sharks (NPOA-
Sharks, discussed further under Protective Efforts) (Ford et al. 2018).
Using 5 years of fishing data and knowledge of the species' biology, an
expert panel evaluated the risk to each species from commercial fishing
by scoring two factors on a scale of one to six: the intensity of the
fishery and its consequence on the species' status. Fishing intensity
for tope sharks was scored at the highest level, reflecting that
``captures are locally to regionally high or continual and
widespread.'' The consequence of the fishery on the species' status was
assessed as intermediate (3 out of 6), reflecting a ``moderate and
sustainable level of impact such as full exploitation rate,'' but no
indication that actual or potential impact is unsustainable.
Overall, although there is clear genetic and demographic
connectivity between the Australian and New Zealand tope shark
populations (see Population Structure), the low rate of trans-Tasman
migration suggested by tagging and CKMR analyses indicates that the New
Zealand population is unlikely to substantially influence the
trajectory of the Australian stock. The tope shark population in
Australian waters has experienced a significant, century-long decline
due to high fishing pressure; however, population abundance is now
increasing. Historical targeting of both mature females and juveniles
in critical nursery areas led to early signs of depletion by the 1940s.
Subsequent stock assessments confirmed the overfished status of the
stock, with biomass estimated to have fallen to as low as 7-12 percent
of pre-exploitation levels by the late 2000s. A formal rebuilding
strategy has been in place since 2008 and recent analyses (fisheries
independent and dependent) indicate that the stock is recovering. The
New Zealand component of the population has sustained high levels of
commercial catch for several decades without evidence of a similar,
widespread collapse. While a single, nationwide biomass trend is
unavailable, regional assessments present a mixed but generally more
stable picture. The population status varies across different
management areas, with some regions appearing stable or increasing
while others show signs of localized depletion and are likely
experiencing overfishing.
SE Pacific
A population abundance estimate and population trend data are not
available for tope sharks in the SE Pacific region. Available landings
data are limited for this region, and species-level assessments based
on these data are hampered by species misidentifications and the
practice of grouping shark landings under generic names--e.g.,
``tollo'' or ``tiburon'' (Sebastian et al. 2008; L[oacute]pez de la
Lama et al. 2018). Despite extensive fishing effort and targeted shark
fisheries in the region, reported landings for tope sharks are low
(Doherty et al. 2014; Walker et al. 2020), and no capture data are
available in the FAO database. Given the extensive fishing effort in
the region and the low reported catches, the species may not be
abundant in the region. A trend analysis was not conducted for this
region as part of the most recent IUCN assessment due to the limited
data available (Walker et al. 2020). Based on the available
information, it is not possible to estimate the abundance and trends
for tope sharks in the SE Pacific.

Distinct Population Segment Analysis

Section 3 of the ESA defines the term ``species'' to include ``any
subspecies of fish or wildlife or plants, and any distinct population
segment of any species of vertebrate fish or wildlife which interbreeds
when mature'' (16 U.S.C. 1532(16)). As mentioned above, the DPS Policy
jointly established by FWS and NMFS in 1996 provides an interpretation
of the term ``distinct population segment'' for purposes of listing,
delisting, and reclassifying species under the ESA and outlines two
elements that must be considered when determining whether a population
of a vertebrate species qualifies as a DPS: (1) the discreteness of the
population segment in relation to the remainder of the taxon to which
it belongs; and (2) the significance of the population segment to the
remainder of the taxon to which it belongs.
The petition expressly requested that if we find that there are
DPSs of tope shark, we evaluate each of those DPSs for listing under
the ESA. After initiating the status review, it became clear that the
severity of threats and management measures differed across the
species' range. As suggested by the IUCN's analyses, population trends
also appeared to vary across the range. Given this information, the
highly structured nature of tope shark populations, and the coincident
discontinuity in the species' range, we elected to evaluate whether the
regional populations of tope sharks qualified as DPSs pursuant to the
DPS Policy.

Discreteness

The discreteness criterion of the DPS Policy may be satisfied if a
population is markedly separated from other populations of the same
taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic discontinuity may
provide evidence of separation. International boundaries may also be
used to delimit a distinct population segment if differences in the
control of exploitation of the species, management of the species'
habitat, the

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conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the ESA. As noted in the
DPS Policy, absolute reproductive isolation is not required in order to
recognize a distinct population segment, as this would be an
impracticably stringent standard.
As discussed previously, the species' global distribution is
discontinuous, with populations inhabiting temperate coastal zones
separated by vast expanses of open ocean or by warm equatorial waters
that coincide with gaps in the species' range. Tagging, telemetry, and
observational data indicate fairly extensive migrations of tope sharks
within most of the aforementioned regions but have not shown movement
of individuals among regions, suggesting a lack of physical and
demographic connectivity. Furthermore, as noted previously, multiple
independent genetic studies using both mtDNA and nuclear
microsatellites consistently reveal a high degree of genetic
structuring among the major regional populations (Bester-van der Merwe
et al. 2017: F<INF>CT</INF> = 0.137, [Phi]<INF>ST</INF> = 0.895, p
<0.05; Chabot and Allen 2009: [Phi]<INF>ST</INF> = 0.84, p <1 x
10-6; Chabot 2015: F<INF>CT</INF> = 0.15, p <0.001). These
analyses show high and statistically significant pairwise measures of
genetic differentiation, the presence of unique regional haplotypes,
and extremely low estimates of inter-oceanic gene flow, confirming a
long history of reproductive isolation. Collectively, and
notwithstanding data gaps due to under- and non-sampled parts of the
range, these studies indicate a regionally isolated population
structure, with little to no contemporary connectivity between tope
shark populations across major ocean basins or the equator. Thus,
overall, and as discussed in further detail below, the best available
scientific and commercial information demonstrates that the regional
populations of tope sharks in the NE Atlantic, SW Atlantic, So. Africa,
NE Pacific, SE Pacific, and SW Pacific (Australia/New Zealand) are
markedly separated from each other, as evidenced by the best available
genetic, tagging, and distribution data.
NE Atlantic
In the NE Atlantic, tope sharks are known to range from Iceland,
the Faroe Islands, and Norway; throughout the Celtic and North Sea;
south to the Bay of Biscayne, the Azores, the Canary Islands, and the
northwestern coast of Africa; and into the Mediterranean Sea (Stevens
1990; Capap[eacute] et al. 2005; Thorburn 2015; Colloca et al. 2019;
Thorburn et al. 2019; Schaber et al. 2022). Available tagging data
gathered over many decades (~1959-2015) indicate that some tope sharks
in the region tend to stay within a relatively small home range, others
may undertake long-distance migrations of ~1,800 km to over 3,500 km
away to other locations within the region (Holden and Horrod 1979;
Stevens 1990; Little 1995; Fitzmaurice et al. 2003; Colloca et al.
2019; Thorburn et al. 2019; Schaber et al. 2022). No trans-equatorial
movements have been recorded.
As noted previously, global genetic studies (Chabot and Allen 2009,
Chabot 2015) also show a lack of population connectivity and a
significant degree of genetic differentiation from other regional
populations (Africa, South America, Australia, and North America).
Thorburn et al. (2015) evaluated the genetic structure of tope sharks
in the region using mtDNA and microsatellite samples from Ireland,
Celtic Sea, southern North Sea, Isle of Wight, Channel Islands,
Balearic Islands, Algeria, SW Scotland, Isle of Man, NW England, and
Azores. All pairwise mtDNA [Phi]<INF>ST</INF> values (-0.0614-0.1936)
and pairwise microsatellite F<INF>ST</INF> values (F<INF>ST</INF> = -
0.0079-0.0192) were low and non-significant (p >0.05) (Thorburn et al.
2015). Results of STRUCTURE analysis (testing k = 1-8 populations) also
provided no evidence of population structure within the region.
Although additional sampling in the eastern Mediterranean and other
areas are needed, results from Thorburn et al. (2015) provide no
evidence of population structure within the region, and in combination
with the movement data, support a conclusion that tope sharks in the NE
Atlantic comprise a single population.
So. Africa
Although there is some uncertainty regarding the exact range of
this species within the So. Africa region, tope sharks are considered
to range from southern Angola to East London, South Africa (Walker et
al. 2020; see Figure 2-2). Freer (1992) noted that tope sharks appear
to be present throughout the area between Walvis Bay, Namibia and Cape
Agulhas, South Africa. This population is physically separated from the
NE Atlantic population by warm equatorial waters, which likely poses a
thermal barrier to tope shark movements (Chabot and Allen 2009), and
from other populations by ocean basins. Genetic analyses confirm this
isolation, with studies by Bester-van der Merwe et al. (2017) and
Chabot (2015) indicating high and significant genetic differentiation
between tope sharks in So. Africa and those from the NE Atlantic,
Australia/New Zealand, and South America. Several studies have also
examined the population structure of tope sharks along the coast of
South Africa and, in particular, across the transition zone between the
southern Atlantic and southern Indian Oceans. However, the several
studies investigating potential structuring within this region have
found no significant genetic differentiation between the two ocean
regions (Bester-van der Merwe et al. 2017, Maduna et al. 2017) and
overall moderate to high gene flow within this portion of the South
Africa coastline (Bitalo et al. 2015, Bester-van der Merwe et al. 2017,
Maduna et al 2017).
NE Pacific
In the NE Pacific, tope sharks range from British Columbia, Canada,
and southward to Baja California, Mexico, and into the Gulf of
California (COSEWIC 2021). Tagging data show that some tope sharks in
this region will undergo long-distance movements along the North
American coast from Southern California to Baja California, Mexico, or
to British Columbia, Canada (Herald and Ripley 1951, Nosal et al.
2021), but no trans-equatorial or trans-Pacific movements have been
documented. Available genetic data indicate that tope sharks sampled
off the coast of southern California are genetically differentiated
from those of So. Africa, NE Atlantic, Australia, and South America
(Chabot and Allen 2009, Chabot 2015). In particular, results of genetic
analyses using both microsatellite and mitochondrial data, indicate
that tope sharks off southern California are genetically distinct from
those off the coast of Peru (F<INF>ST</INF> = 0.09, p <0.001;
mtF<INF>ST</INF>/[Phi]<INF>ST</INF> = 0.19/0.67, p <0.001; Chabot and
Allen 2009, Chabot 2015). Estimated number of migrants per generation
between regional populations was also low (Chabot and Allen 2009), and
while the gene flow estimate from California to Peru was found to be
higher (i.e., 0.257) relative to other comparisons, it was well below
the estimated self-recruitment rates for each region (i.e., 0.998 and
0.692, Chabot 2015). While genetic data to explore potential population
structuring at a finer-scale within the NE Pacific are not available,
the available data suggest that tope sharks within the NE Pacific are
part of single, seasonally-migratory population.
SW Pacific
Tope sharks in this region have been reported from Houtman's
Abrolhos to Cape Leeuwin in Western Australia, eastward to Moreton Bay
in Southern

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Queensland, around Lord Howe Island, Tasmania, around the North and
South Islands of New Zealand, and as far east as the Chatham Islands
(Olson 1954; Hernandez et al. 2015; <a href="https://GBIF.org">https://GBIF.org</a> database, accessed
on August 25, 2023). As noted previously, three large-scale genetic
studies, which included samples from Australia and New Zealand, showed
a high degree of genetic differentiation among all sampled regions
(Bester-van der Merwe et al. 2017: F<INF>CT</INF> = 0.137,
[Phi]<INF>ST</INF> = 0.895, p < 0.05; Chabot and Allen 2009:
[Phi]<INF>ST</INF> = 0.84, p < 1 x 10-6; Chabot 2015:
F<INF>CT</INF> = 0.15, p < 0.001). A fourth study, using both
mitochondrial and microsatellite DNA and samples collected from six
sites in Australia, four sites in New Zealand, and one site in Chile
(Santiago), indicated significant genetic differences in all pairwise
comparisons involving the samples from Chile (p < 0.001) but supported
a single population model for Australia and New Zealand
(Hern[aacute]ndez et al. 2015).
Tagging data support the patterns indicated by the genetic data.
Specifically, extensive tagging efforts in both Australia and New
Zealand have indicated migration of tope sharks between the two
countries in both directions across the Tasman Sea, but there has been
no indication of movements to other regions (Coutin et al. 1992; Walker
et al. 1997; Hurst et al. 1999; Brown et al. 2000; Francis 2010).
Whether the observed migrations between Australia and New Zealand are
associated with genetic exchange has been the subject of considerable
study in the region. As noted above, Hern[aacute]ndez et al. (2015),
using both mtDNA and nuclear microsatellites from numerous locations,
found no significant genetic structure between the two countries. A
subsequent, high-resolution study on juvenile sharks from nursery areas
in Tasmania and New Zealand also found no significant genetic
differentiation based on thousands of genome-wide single nucleotide
polymorphisms (Devloo-Delva et al. 2019). While one study (Bester-van
der Merwe et al. 2017) reported statistically significant genetic
differentiation based on a panel of microsatellite markers, a re-
analysis of those samples suggested the result may have been influenced
by small sample sizes and the presence of related individuals (Devloo-
Delva et al. 2019). Overall, the best available genetic data indicate
that tope sharks in Australia and New Zealand are genetically distinct
from other regional populations, and that there is sufficient
demographic and genetic exchange to consider Australia and New Zealand
a single, interbreeding population.
SW Atlantic
Within the SW Atlantic, tope sharks range from Rio Grande do Sul,
Brazil, south to Pen[iacute]nsula San Juli[aacute]n in Argentine
Patagonia (Peres and Vooren 1991; Menni et al. 2010; Chiaramonte 2015).
The results of a genetic study of tope sharks across the Southern
Hemisphere indicated significant differentiation based on both mtDNA
and microsatellites between Argentina and all other sample locations
(South Africa, Australia, New Zealand), as well Chile
([Phi]<INF>ST</INF> = 0.151, F<INF>ST</INF> = 0.236, p <= 0.05; Bester-
van der Merwe et al. 2017). Although Bester-van der Merwe et al. (2017)
detected a single shared haplotype between Chile and Argentina and
similarly, Chabot and Allen (2009) noted a shared mtDNA haplotype
between single samples from Argentina and Peru, the presence of these
shared ancestral haplotypes does not imply contemporary gene flow, and
this finding is not sufficient to override the broader pattern of
differentiation observed in the nuclear DNA, which reflects a longer
history of reproductive isolation. Taken together, the limited,
available data suggest that the populations of tope sharks on the
Pacific and Atlantic coasts of South America likely share some degree
of historical connectivity, but contemporary gene flow appears to be
limited (Bester-van der Merwe et al. 2017). There are no tagging data
to suggest any movement of individuals between the two South America
populations; although, this does not appear to have been thoroughly
investigated.
Tope sharks have been observed to make seasonal migrations within
this region, moving from shelf waters off southern Brazil in colder
months to areas southward and deeper during warmer months (Ferreira and
Vooren 1991; Peres and Vooren 1991; El[iacute]as et al. 2004; Lucifora
et al. 2004; Cuevas et al. 2014; Klippel et al. 2016; Trobbiani et al.
2021). Results from two tagging studies are consistent with this
pattern and indicate long-distance movements of tope sharks within the
region from Golfo Nuevo, Argentina (~42.4[deg] S, n = 3) to points
northward with the shifting seasons (to ~40[deg]12' S, ~38[deg] S,
~35[deg]18' S), with one shark having travelled a minimum distance of
1,425 km in 6 months (Irigoyen et al. 2015; Jaureguizar et al. 2018).
An analysis of mtDNA from tope sharks sampled in 2 areas along the
coast of Argentina--off Buenos Aires (n = 10) and in Golfo San
Mat[iacute]as (n = 12)--indicated no significant differences between
locations (statistics not provided; Cuevas et al. 2016). Although
relatively limited, the available data collectively provide support for
the hypothesis that tope sharks within this region comprise a single
migratory population and provide no indication of finer-scale
population structuring.
SE Pacific
Tope sharks in this region are considered to range from Ecuador to
Chile (Walker et al. 2020). As discussed previously, results of several
studies indicate that tope sharks in this region are significantly
genetically differentiated from tope sharks in the NE Pacific
(California), SW Atlantic (Argentina), NE Atlantic (Irish and Celtic
Seas), South Africa, Australia, and New Zealand (Chabot and Allen 2009;
Chabot 2015; Hern[aacute]ndez et al. 2015; Bester-van der Merwe et al.
2017). In particular, and as discussed above, tope shark populations on
the Pacific and Atlantic coasts of South America have been found to be
significantly differentiated based on assessments of both mitochondrial
and microsatellite DNA ([Phi]<INF>ST</INF> = 0.151, F<INF>ST</INF> =
0.236, p <= 0.05; Bester-van der Merwe et al. 2017). We are not aware
of any tagging data indicating movement of individuals between the two
South America populations or between the NE and SE Pacific populations.
As noted above, both Bester-van der Merwe et al. (2017) and Chabot
and Allen (2009) noted a shared mitochondrial haplotype between single
samples from both sides of South America. However, the presence of
these two shared ancestral haplotypes does not necessarily indicate
contemporary gene flow, and we do not find this to be sufficient
evidence to override the broader pattern of differentiation observed in
the nuclear DNA, which reflects a longer history of reproductive
isolation.

Significance

If a population segment is considered discrete, the biological and
ecological significance of the population segment(s) is considered
relative to the taxon to which it belongs. As outlined in the DPS
Policy, considerations with respect to the ``significance'' criterion
may include, but are not limited to, whether a loss of the discrete
population segment would result in a significant gap in the species'
range; whether the discrete population segment persists in a unique
ecological setting; and whether the discrete population segment differs
markedly from other populations of the species in its genetic
characteristics.

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With respect to the six discrete populations identified above, we
conclude that the loss of any of the populations would create a
significant and possibly permanent gap in the species' range. Although
tope sharks are capable of long-distance migrations (e.g., 4,000 km),
the available tagging data also indicate that tope sharks exhibit
general fidelity to their region and, in some cases, fidelity to
particular coastal habitats (Stevens 1990, Thorburn et al. 2019, Brown
et al. 2000, Nosal et al. 2021). There is no evidence of movement
between regional populations, and the available genetic data provide
strong support for the conclusion that major ocean basins and warm
equatorial waters are barriers to dispersal for tope sharks.
Additionally, as established in the analysis of discreteness above,
there is clear evidence of marked genetic differences among the
populations. The high estimates of genetic differentiation and presence
of unique haplotypes and genotypes within regions (e.g., Chabot and
Allen 2009, Chabot 2015, Hernandez et al. 2015) indicate that these
populations represent significant components of the species' overall
genetic diversity. Loss of any one of the regional populations would
result in the loss of unique genetic variation within the taxon as a
whole.

DPS Conclusion

Based on a review of the best scientific and commercial data
available, we find that the six regional populations of tope shark--NE
Atlantic, So. Africa, SW Atlantic, NE Pacific, SE Pacific, and SW
Pacific--satisfy the discreteness and significance criteria of the DPS
Policy. The discreteness of these populations is supported by the
discontinuous and spatially isolated distribution of the species, the
high degree of genetic structuring among the regional populations, and
the lack of known movement between them. Each of the regional
populations is also significant to the larger taxon, as the loss of any
one regional population would result in a significant gap in the
species' global range and a loss of unique genetic diversity. For these
reasons, we have determined that the regional populations of tope shark
in the NE Atlantic, So. Africa, SW Atlantic, NE Pacific, SE Pacific,
and SW Pacific each qualify as a DPS.

Extinction Risk Analysis

After compiling and reviewing the best scientific and commercial
data available, as summarized in this document, the three-person team
of biologists from the Office of Protected Resources systematically
evaluated the overall risk of extinction facing each DPS now and in the
foreseeable future. The analysis integrated two components: a threats
assessment and a demographic risk analysis. This approach allowed the
team to connect the sources and nature of past and ongoing threats to
the tope sharks, the biological consequences of past threats, and the
likely biological response to present and future threats--thereby
providing a comprehensive evaluation of the overall extinction risk of
each DPS.
The threats assessment drew upon the information presented in
Section 4.0 of the Status Review Report, which is summarized in this
document, to characterize the impact of threats identified in section
4(a)(1) of the ESA: (A) the present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; and (E) other natural or manmade
factors affecting its continued existence.
Demographic risks to the DPSs were assessed using basic principles
of conservation biology and by following an approach modified from
McElhany et al. (2000) that focused on four key demographic factors:
abundance, productivity, spatial distribution, and diversity. These
four demographic factors, outlined in McElhany et al. (2000), have been
used in many previous ESA status reviews conducted by NMFS and reflect
concepts that are well-founded in conservation biology and that
individually and collectively provide strong indicators of extinction
risk. The demographic risk analysis served as an assessment of the
manifestation of past threats that have contributed to the DPS's
current status and informed the consideration of the biological
response of each DPS to present and future threats.
In evaluating both the threats and the demographic risks, the team
considered the extent to which relevant data were available and the
quality of those data. To ensure a consistent and systematic approach
to assessing each threat and demographic risk factor across the six
DPSs, they rated each factor according to the following qualitative
scale:
Unknown: The current level of information is either unavailable or
unknown for this threat or demographic factor, such that its
contribution to the extinction risk of the DPS cannot be determined;
Very low: It is unlikely that this threat/factor contributes
significantly to risk of extinction, either by itself or in combination
with other threats/factors;
Low: It is unlikely that the threat/factor contributes
significantly to the species' long-term or near future risk of
extinction by itself, but there is some concern that it may in
combination with other factors;
Moderate: This threat/factor contributes significantly to long-term
risk of extinction, but does not in itself constitute a danger of
extinction in the near future;
High: This threat/factor contributes significantly to long-term
risk of extinction and is likely to contribute to near-term risk of
extinction;
Very high: This threat/factor by itself indicates danger of
extinction in the near future.
Each of the three team members independently assigned a qualitative
rating to each of the identified threats and the four demographic risk
factors, considering the scope (spatial extent), severity (magnitude),
and persistence (timeframe) for the particular factor. Each member was
also asked to rate the level of data sufficiency or certainty by
applying one of the following three categories to their ratings: +
(high): an abundance of data is available for the threat and its
effects on the species, and the reviewer has no reservations in
reaching a rating decision; 0 (medium): data are available for the
threat and its effects on the species, and a rating can be assigned but
additional data are desired;-(low): ratings are based on expert
opinion, based on biological concepts or inferences from data or
information on other species or areas. After rating each threat and
risk factor independently, the team convened to discuss their ratings,
associated rationales, and the sufficiency of the relevant data, to
assign a final rating for each threat and risk factor. Results of those
discussions are provided in the Status Review Report and are summarized
here.
Lastly, to assign an overall extinction risk level, the team
considered each of the threats and demographic risk factors, their
interactions, and the associated ratings and levels of certainty. They
rated the overall risk of extinction to each DPS qualitatively, using
categories of ``high risk,'' ``moderate risk,'' or ``low risk''
consistent with previous NMFS status reviews and as described as
follows:
High risk: A DPS with a high risk of extinction is at or near a
level of abundance, productivity, spatial structure, and/or diversity
that places its continued persistence in question. The

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demographics of a DPS at such a high level of risk may be highly
uncertain and strongly influenced by stochastic or depensatory
processes. Similarly, a DPS may be at high risk of extinction if it
faces clear and present threats (e.g., confinement to a small
geographic area; imminent destruction, modification, or curtailment of
its habitat; or disease epidemic) that are likely to create imminent
and substantial demographic risks;
Moderate risk: A DPS is at moderate risk of extinction if it is on
a trajectory that puts it at a high level of extinction risk in the
foreseeable future (see description of ``High risk'' above). A DPS may
be at moderate risk of extinction due to current and/or projected
threats or declining trends in abundance, productivity, spatial
structure, or diversity;
Low Risk: A DPS is at low risk of extinction if it is not at
moderate or high level of extinction risk (see ``Moderate risk'' and
``High risk'' above). A DPS may be at low risk of extinction if it is
not facing threats that result in declining trends in abundance,
productivity, spatial structure, or diversity. A DPS at low risk of
extinction is likely to show stable or increasing trends in abundance
and productivity with connected, diverse populations.
To assign an overall extinction risk rating while accounting for
uncertainty, the team applied the same ``likelihood point'' method as
has been used in many prior NMFS status reviews (e.g., scalloped
hammerhead, shortfin mako shark, Pacific salmon, Pacific herring, black
abalone). In this approach, each individual distributed 10 likelihood
points among the three extinction risk levels to rate the overall
extinction risk to each DPS throughout its range. After likelihood
points were independently assigned, ratings were shared and discussed.
Following this initial discussion, each team member was allowed, but
not required, to revise their ratings. After a subsequent team
discussion, the final likelihood point distributions from each team
member were compiled and used to assign the overall risk category to
each DPS. Results of that analysis are provided in section 6.0 of the
Status Review Report and are summarized below. Lastly, and as explained
further in Significant Portion of its Range Analysis below, this same
general approach was applied to evaluating extinction risk within
potentially significant portions of each DPS's range.
The team did not make recommendations or conclusions with respect
to whether any tope shark DPSs should be listed under the ESA or
classified as threatened or endangered species under the ESA. Rather,
the team limited their analysis to considering the best available data,
as summarized in this draft report, and drew scientific conclusions
about the overall risk of extinction faced by each DPS under present
conditions and over the foreseeable future.

Foreseeable Future

As noted previously, section 3 of the ESA defines an endangered
species as any species which is in danger of extinction throughout all
or a significant portion of its range and a threatened species as any
species which is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its range
(16 U.S.C. 1532(6) and (20)). When evaluating threats and risks to each
DPS, the team considered how each identified threat or risk factor may
affect the tope sharks over the ``foreseeable future.'' The term
foreseeable future is described in our regulations as extending as far
into the future as we can make reasonably reliable predictions about
the threats to the species and the species' responses to those threats
(50 CFR 424.11(d)). As stated in the regulations, we describe the
foreseeable future on a case-by-case basis using the best available
data and taking into account considerations such as the species' life-
history characteristics, threat-projection timeframes, and
environmental variability (50 CFR 424.11(d)). While we are not required
to identify a specific period of time for the foreseeable future (50
CFR 424.11(d)), we do indicate a specific time period for the
foreseeable future where possible. In other cases, where data are not
sufficient to allow for such precision, we describe the foreseeable
future as a range of years or qualitatively.
On November 21, 2025, the Services proposed to revise portions of
the ESA section 4 regulations (90 FR 52607). The proposed regulations
would, in part, revise the regulatory framework for determining the
``foreseeable future'' in 50 CFR 424.11(d). If finalized, those section
4 regulations would apply prospectively only, and thus would not apply
to listing determinations finalized prior to their effective date. For
purposes of this determination, however, we considered the proposed
revisions to the ``foreseeable future'' framework regulation and
whether the conclusions would be any different from those reached under
the existing regulations in 50 CFR 424.11(d). We have determined that
the analysis and conclusions presented here would not be any different.
As a long-lived, late-maturing species, tope sharks have a fairly
long estimated generation length of about 23 to 26.3 years (Walker et
al. 2020; Winker et al. 2020). Given these life history
characteristics, it could take at least several generations for the
impacts of any operative threat to have a demonstrated impact on tope
shark populations. Likewise, it would likely take at least several
generations for the benefits of any management measure to manifest
themselves at the population level. Thus, a biologically relevant
foreseeable future was considered to be about three generations, i.e.,
about 69-79 years. Where the best available data indicate a different
or more specific foreseeable future, that specific information is
provided in the discussion below.

Significant Portion of Its Range Analysis

As part of the extinction risk assessment, the team was also asked
to consider whether any DPSs were facing greater risk of extinction
within any significant portion of their ranges relative to their status
throughout the range. Under the ESA, a species may qualify as
``threatened species'' or ``endangered species'' based on its status
throughout all or in a ``significant portion of its range'' (16 U.S.C.
1531(6) and (20)). In other words, species may be listed on the basis
of their status across their entire range or based on their status in a
significant portion of their range (Defenders of Wildlife v. Norton,
258 F.3d 1136 (9th Cir. 2001); CBD v. Everson, 435 F. Supp. 3d 69
(D.D.C. 2020)).
A policy for interpreting the statutory phrase ``significant
portion of its range'' (or SPR) was developed by NMFS and FWS in 2014
(79 FR 37578, July 1, 2014); however, the standard outlined in that
policy for determining whether a portion of a species' range qualifies
as a significant one has since been invalidated (Desert Survivors v.
DOI, 336 F. Supp. 3d 1131 (N.D. Cal. 2018) (Bi-state sage grouse remedy
order; vacating the definition of ``significant''). NMFS has since
adopted an approach that focuses on the biological significance of the
members of the species within a particular portion of the range to the
long-term viability of the species as a whole--or, in this case, to the
DPS as a whole.
In conducting an SPR analysis, we may elect to first ask either of
the following: (a) what is the status of the species in that portion or
(b) is the ``portion'' biologically significant to the overall species.
If the answer to the first

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question analyzed is affirmative (i.e., the species is at moderate or
high risk in the portion or the portion is biologically significant),
then we would continue the analysis to consider the other question. If
either question is answered in the negative, we would not need to
investigate the remaining question, as there would be no basis to
change the range-wide conclusion (79 FR 37578, July 1, 2014).
The 2014 SPR Policy defines ``range'' in geographic terms, and
therefore the selection of portions for consideration are premised on a
geographically oriented rationale. Because there are infinite ways in
which a range could be divided for purposes of an ``SPR analysis,'' the
only portions ultimately considered in the analyses are those that that
were considered to have a reasonable likelihood of being at moderate or
high risk of extinction and a reasonable likelihood of being
biologically significant to the DPS. Unless portions met both of these
conditions, they were not further considered in the SPR analysis. In
the sections below, we explain how this conclusion was reached for each
DPS.
In evaluating whether a particular portion of a DPS's range was
``significant,'' the team was asked to consider the contribution or
role of the sharks within that portion to the viability of the DPS as a
whole. To the extent possible with the available data, they considered
the role of the portion from a historical, current, and future
perspective, as each of these temporal contexts are relevant to
assessing the biological importance of that portion to the long-term
viability of the DPS. For instance, sharks in some portion of the DPS's
range may no longer be contributing to the viability of the DPS because
tope sharks may currently be at very low abundance (or productivity or
diversity, etc.) in that area; but, historically, sharks in that
portion may have served a biologically important role for the DPS's
viability (e.g., served as an important source population, or provided
connectivity and gene flow among members of the DPS). In conducting
this part of the analysis, the team was also mindful that to qualify as
a significant portion, they had to also conclude that the particular
portion was not so important to the DPS that it actually drives the
range-wide status of the DPS. In other words, the biological importance
of individuals within the portion cannot be so great that status in
that portion is determinative of the status of the DPS throughout its
entire range, as that would render the statutory SPR phrase superfluous
to the ``throughout all'' phrase (see Defenders of Wildlife v. Norton,
258 F.3d 1136 (9th Cir. 2001)).

Summary of Section 4(a)(1) Factors Affecting All DPSs

In this section we present information relating to section 4(a)(1)
factors as they apply to all of the tope shark DPSs. For certain
threats to tope sharks, information is available only at a global scale
or generically for the species and thus generally applies to all six
DPSs of tope sharks, rather than any one specific DPS. For other
threats, such as overutilization and inadequacy of existing regulatory
mechanisms, background information that applies to all six DPSs is
presented here, and more specific information about the factors
affecting each DPS is presented in subsequent sections. We considered
the information presented here in our extinction risk analyses for each
DPS as detailed in later sections of this document.

The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range

Ocean temperature, which is projected to increase over the
foreseeable future under plausible future greenhouse gas emission
scenarios (Fox-Kemper et al. 2021), appears to be an important driver
of tope shark distributions (Klippel et al. 2016). While tope sharks
occur in a wide range of water temperatures, ranging from minimums of
at least 8.1 [deg]C to maximums of at least 27 [deg]C, they typically
occur in waters between 12 and 21 [deg]C and are hypothesized to avoid
warmer, equatorial waters (West and Stevens 2001; Menni et al. 2010;
Cuevas et al. 2014; Kippel et al. 2016; Rogers et al. 2017; Jaureguizar
et al. 2018). Although thermal tolerances and preferences are not fully
resolved for this species, increases in ocean temperatures are likely
to influence the future distribution of tope sharks and may affect the
availability of suitable habitat. Poleward range shifts are generally
predicted for marine fishes (bony and cartilaginous) under modeled
future oceanic conditions (Morley et al. 2018; Braun et al. 2023;
Hodapp et al. 2023). For species with cross-equatorial distributions,
changing ocean conditions are also predicted to cause a widening gap in
suitable habitat around the equator (Hodapp et al. 2023). Many marine
fishes are also predicted to experience net losses in suitable habitat
with continued ocean warming, with the magnitude of these losses
varying by species and region (Braun et al. 2023; Hodapp et al. 2023).
Some fish species, on the other hand, are predicted to have a net
increase in suitable habitat (Morley et al. 2019).
No published analyses of ocean warming-driven range shifts
specifically for tope sharks are available; however, the team estimated
potential future shifts by applying the same basic approach as Hodapp
et al. (2023), comparing current ``suitable'' habitat to model-
predicted ``suitable'' habitat in the foreseeable future. The habitat
suitability model uses verified occurrence data from publicly available
sources (e.g., FishBase) and seven environmental data layers--depth,
surface and bottom temperature, salinity, primary productivity,
dissolved oxygen, sea ice concentration, and distance to land--that
represent key physical and biological factors structuring the species'
distribution at large scales and thus which can be used as predictors
of species presence. These data are assigned and modeled at the scale
of 0.05 degree grid cells (Kaschner et al. 2019, Kesner-Reyes et al.
2020; Reygondeau et al. 2026). In their analysis, the team quantified
the projected change in suitable habitat area using the Habitat
Suitability Index (HSI) for present-day versus future conditions, which
was calculated on a scale of 0 to 1,000. They first defined
``suitable'' habitat as any grid cell with an HSI value greater than or
equal to a presence/absence cutoff value of 685. This is essentially
the point at which the trade-off between correctly predicting where the
species occurs (i.e., values greater than the cutoff) and where it does
not occur (i.e., values less than the cutoff) is maximized. They then
compared the total suitable area (square (sq.) km) in each time period
to calculate the percent change between present and predicted suitable
habitat. The results of this analysis indicate a potential loss of
suitable habitat for tope sharks around the equator and an expansion of
suitable habitat near the poles. This analysis also predicts that the
global range of tope sharks would increase by roughly 13.2 percent,
particularly in the Northern Hemisphere, but that changes would vary
considerably by region. The NE Pacific is projected to experience the
greatest increase in suitable habitat area by percentage (28.6
percent), followed by the NE Atlantic (13.6 percent), SW Pacific (13.4
percent), SW Atlantic (12.1 percent), and SE Pacific (6.6 percent). The
So. Africa region is predicted to experience an estimated 6.4 percent
reduction in suitable habitat area. The team noted, however, that this
habitat suitability model does not account for various biological,
ecological, or other

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physical factors that may influence habitat use by tope sharks in
future ocean conditions, such as changes in migratory behaviors, shifts
in ecological interactions, or barriers to migration (Kashner et al.
2019). Thus, we caution that while the qualitative results of this
analysis are consistent with observations and other analyses of range
shifts in marine species and are informative for tope sharks, the
quantitative results of the team's analysis are associated with an
unknown level of uncertainty and are not considered to be precise
predictions.
In addition to the first-order impacts of elevated ocean
temperatures, marine systems are also expected to experience more
complex, cascading changes over the next century, including altered
ocean currents, oceanographic cycles, productivity, and food web
dynamics, which have been shown to impact coastal sharks (Howard et al.
2013; Holbrook et al. 2019; Fox-Kemper et al. 2021; Matich et al.
2024). Available data suggest that tope sharks are likely vulnerable to
these broader environmental shifts. For example, using tope shark
landings data from Andalusia (southern Spain) from 1986 to 2013, Baez
et al. (2016) found a significant negative correlation between tope
shark landings and the North Atlantic Oscillation of the prior year (r
= -0.506, p = 0.006), and a significant positive correlation of tope
shark landings and accumulated snow from the prior year (r = 0.596, p =
0.009), suggesting that tope shark landings in this region may be
influenced by the main climatic oscillation and conditions associated
with increased input of land-based nutrients into the marine
environment (and presumably increased plankton productivity). In
addition, results of a sensitivity analysis by Ortega-Cisneros et al.
(2018) for 40 species in the southern Benguela current system, which
was developed using 14 life-history traits for each species, indicated
that tope sharks were among the most sensitive species in this region,
and that they would likely have a low capacity to respond to the
effects of ocean warming and associated environmental impacts. Taken
together with the previously discussed modeling results, this
information suggests with a high degree of certainty that ocean warming
and associated impacts on marine systems will affect tope shark
populations over the foreseeable future; however, the nature (e.g.,
changed distribution, productivity, abundance) and severity of any
effects remain difficult to predict given the available data.
In addition to potentially altering the availability of their
suitable habitat, increased water temperatures and other direct effects
from changing ocean conditions on marine habitats, such as ocean
acidification, could result in physiological and behavioral
consequences for tope sharks. Ocean temperature, for instance, may
provide important cues for migration and influence aspects of tope
shark biology and physiology (e.g., gestation, spermatogenesis,
swimming, foraging; Olsen 1954; Theron 2001; Jaureguizar et al. 2018;
Thorburn et al. 2019; Nosal et al. 2021). Increasingly acidic ocean
conditions as the oceans continue to take up atmospheric carbon dioxide
(e.g., pH = 7.5-7.9; Canadell et al. 2021) have been shown in
controlled, laboratory experiments to have various effects on sharks,
including reduced survival and growth and impaired foraging behavior
(Rosa et al. 2017; Vilmar and Di Santo 2022). As evident from the
available studies, which do not address tope sharks, there is also
considerable intra-specific variation in sharks' sensitivities and
responses to these habitat stressors. Therefore, although ocean warming
and acidification trends are expected to continue over the foreseeable
future regardless of the rate of carbon dioxide (CO<INF>2</INF>)
emissions (IPCC 2023), additional study is needed to understand both
the independent and combined effects of warmer water temperatures and
ocean acidification on tope sharks.
The shallow coastal habitats that serve as important pupping and
juvenile nursery areas for tope shark are naturally subject to large
environmental fluctuations; however, as weather patterns continue to
change, these natural fluctuations are expected to become more extreme
(Cooley et al. 2022) and could present physiological challenges for
tope sharks. One potential challenge within these shallow, nearshore
habitats is increased variability in salinity as a result of changes in
evaporation and freshwater input (e.g., increased droughts, increased
frequency and severity of extreme rain events). As osmoconformers
(i.e., organisms that maintain their internal body fluids at the same
salt concentration as their environment), sharks may experience
negative physiological effects as a result of rapid or extreme changes
in salinity, but evidence of this is limited. In one study, which
examined the effects of hypersaline conditions by exposing young-of-
year (YOY) tope sharks (n = 3-8) to elevated salinity (41 parts per
thousand ([permil])) for 48 hours, the tope sharks exhibited a decline
in metabolic rate (35 percent decline in oxygen consumption) and some
signs of protein damage (Tunnah et al. 2016). Overall, however, the
tope sharks showed an effective physiological response to hypersalinity
(Tunnah et al. 2016). Another study by Morash et al. (2016) examined
the effects of hyposalinity by exposing YOY tope sharks (n = 10) to low
salinity conditions (25.8 [permil]) for 48 hours. Results of this study
also indicated a significant decline in metabolic rate (~15 percent),
but no evidence of protein damage and an overall effective response to
hyposalinity (Morash et al. 2016). As both of these studies were short-
term and examined salinity changes in the absence of other physical
changes to the habitat (e.g., increase temperatures), it is not clear
how tope sharks would respond to more frequent or longer duration
events.
In addition to the various impacts to tope shark habitats from
changing ocean conditions, coastal development and other human
activities within the coastal zone can modify, disturb, or degrade
important nearshore areas, as has been clearly evidenced by observed
declines in species abundance and diversity and losses of seagrasses in
estuaries and coastal seas around the world (Lotze et al. 2006).
Coastal development and urbanization can negatively affect coastal
habitats by, for example, increasing sedimentation and nutrient input,
and reducing habitat complexity. Degradation of tope shark nursery
areas in southern Tasmania and Victoria, Australia, has been cited as a
possible cause for the substantial decline in the abundance of tope
shark pups in these areas between the 1950s and 1990s (TSSC 2009;
Stevens and West 1997); however, causal links between the habitat
degradation and the observed declines in juvenile tope sharks were not
established. Subsequent surveys in southern Tasmania (Upper Pittwater
and Frederick Henry Bay) during 2012-2014 also suggest that abundance
of YOY tope sharks have increased or at least stabilized in these
nursery areas since the 1990s (McAllister et al. 2018).
Various toxic pollutants, including heavy metals (e.g., arsenic,
cadmium, lead, mercury), plastics, pesticides, and hydrocarbons, are
also likely to be elevated within coastal waters adjacent to human
population centers. As long-lived, fairly high-trophic level consumers,
tope sharks can bioaccumulate various contaminants, which could
potentially have negative consequences on the health and physiology of
the sharks (Scheuhammer

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et al. 2007; Skomal and Mandelman 2012; Alves et al. 2022). Tope sharks
are known to bioaccumulate mercury, with larger, older adults having
higher concentrations in their muscle tissue (sometimes in excess of
legal limits set for human consumption) (Walker 1999; McKie and Topping
1982; Domi et al. 2005; Torres et al. 2014). Based on sampling of tope
sharks bycaught off the relatively pristine Azores (where hydrothermal
vents are a natural source of metals) in 2013, Torres et al. (2014)
found levels of bioaccumulated arsenic and mercury (maximums of 28.98
<plus-minus> 1.26 and 0.57 <plus-minus> 0.01 milligram/kg wet weight,
respectively) in the largest size-class of males and females (>100 cm
TL, n = 23-26) that exceeded the maximum limits established in some
countries for human consumption. Ingestion of plastics, which are now
ubiquitous in marine environments, has been reported for various marine
species, including sharks, and is an environmental issue of growing
concern (Harris 2020; Janardhanam et al. 2022; Munno et al. 2024).
Other than the report of mesoplastics (5-20 mm) in one tope stomach (of
31) collected from the English Channel in 2012 (Biton-Porsmoguer 2022),
however, we are not aware of any assessments of rates of plastics
ingestion by tope sharks or resulting health consequences (see also
Munno et al. 2024).
With respect to the pollutants that have been found at elevated
levels within tope sharks, the health implications for the sharks are
poorly understood. In the study conducted by Torres et al. (2014), the
bioaccumulated levels of mercury in tope sharks were highly correlated
with selenium (r = 0.91), which is thought to play a role in mercury
detoxification (Storelli and Marcotrigiano 2002; Braco et al. 2007). A
preliminary study by Bonwick et al. (1990) also showed relatively high
levels of metallothionein-like proteins in the liver of an adult male
tope shark (126 cm TL) that had been captured in the northern Irish
Sea/Liverpool Bay, an area considered to be heavily contaminated with
trace metals. Metallothioneins are thought to play a role in regulating
essential trace metals and detoxification of non-essential trace metals
(Hauser-Davis 2020). Both studies, thus, provide some limited evidence
that tope sharks may be capable of preventing or inhibiting the toxic
effects of mercury, at least to some extent. Overall, however, it
remains unclear to what extent toxic pollutants--operating alone or in
combination with other potential threats (e.g., disease)--are affecting
the health and status of tope sharks.
In summary, the available data indicate that, due to ocean warming
and associated effects on marine systems, the distribution of tope
sharks will likely change, and the availability of suitable habitat may
expand in some locations, particularly in the Northern Hemisphere,
while declining elsewhere, particularly in equatorial and tropical
regions. Other forms of habitat degradation, particularly reduced water
quality, are also likely to affect tope shark habitats, particularly
those nearshore habitats used predominantly by juveniles and pregnant
females. Exposure to and bioaccumulation of certain contaminants like
mercury, while well documented in tope sharks, has poorly understood
consequences on their health and survival. Because sufficient data to
evaluate the extent to which tope sharks' health and abundance are
affected by these forms of habitat degradation are currently lacking,
we cannot make firm conclusions about the severity of these threats or
how they will affect tope sharks over the foreseeable future.
Discerning whether any observed declines in tope shark abundance within
coastal habitats were driven by habitat degradation, such as those
observed in nursery areas in Australia, is further challenged by the
fact that observed population declines are largely attributed to
overfishing. Lastly, we acknowledge that impacts to tope shark habitat
will co-occur and interact, and the extent to which the various changes
to their habitat from changing environmental conditions will alter or
exacerbate their susceptibility to other threats (e.g., fishing and
bycatch, toxic pollutants) is uncertain.

Overutilization

To evaluate threats to tope sharks under section 4(a)(1)(B) of the
ESA, the team considered information regarding commercial,
recreational, scientific, and educational use of this species. They
found no evidence or indication that tope sharks have been or are
currently being overutilized for scientific or educational purposes;
therefore, those topics are not discussed further. Instead, our review
focuses on fishing activities, which have been an important driver of
population dynamics for this species in every region where it occurs.
Tope sharks are mainly taken in industrial fisheries but are also
taken in artisanal, recreational, and subsistence fisheries. Primary
capture methods include pelagic and demersal gillnets and longlines;
tope sharks are also taken in bottom and pelagic trawls, troll lines,
trammel nets, and by hook-and-line (Bureau of Marine Fisheries (BMF)
1949; Braccini et al. 2009; Walker et al. 2020). The species' use of
both epipelagic (0-200 m depths) and mesopelagic waters (200-1,000 m
depths) and behaviors including vertical movements put them at risk of
capture in both demersal fishing gear when over continental shelves and
deeper-set gear when in oceanic waters (West and Stevens 2001; Rogers
et al. 2017; Thorburn et al. 2019; Gonzalez-Garcia et al. 2020; Schaber
et al. 2022).
Tope sharks have been targeted in commercial fisheries primarily
for their meat, fins, and liver oil in areas across their range.
Historically, tope sharks were harvested for use in shark fin soup, for
consumption or sale, for skins, and for various other purposes (e.g.,
fertilizer; Ripley 1946; Walker 1999). Harvest of tope sharks quickly
accelerated in some regions during the late 1930s and early 1940s when
World War II disrupted cod fishing and access to European sources of
cod liver oil, which had served as an important source of vitamin A.
Tope shark liver oil, which is rich in vitamin A, became an effective
replacement (Ripley 1946; BMF 1949; Olsen 1954; Freer 1992). Fisheries
expanded rapidly in response to this market demand, largely without
regulation. Following the war, tope shark landings decreased as a
consequence of the renewed availability of cod liver oil, the advent of
commercially available synthetic vitamin A in the 1950s, and declines
in tope shark abundance (Olsen 1984, Freer 1992, Walker 1999).
Commercial harvest did continue, and in some regions even expanded, as
tope sharks were targeted for fins and meat in addition to liver oil,
which was then used in multiple manufactured products (Freer 1992;
Walker 1999; Vannuccini 1999). In the early 1970s, commercial harvest
of tope sharks declined relatively rapidly as the public became
increasingly aware of the significant mercury load in larger fishes and
as various legal restrictions on the concentrations of mercury in fish
products were put in place (Olsen 1984; Walker 1999; Freer 1992). As
concerns about mercury eased, global landings peaked in the 1980s with
annual harvest estimated at over 12,000 mt, though this is likely an
underestimate. Multiple factors contributed to this later peak in
global landings, such as improved fishing gears and technology (e.g.,
monofilament gillnets), and concurrent declines in the abundance of
other inshore finfish species (Olsen 1984;

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Francis 1998; Walker 1999; Megalofonou et al. 2005).
Currently, tope sharks are not a primary commercial target in most
regions; however, they are often retained when captured incidentally
(i.e., as bycatch; Walker et al. 2020). Incidentally captured tope
sharks are sometimes discarded; however, discards appear to make up a
small percentage of overall estimated fisheries mortality of tope
sharks (Pauly et al. 2020). Discard mortality can be categorized as at-
vessel mortality, which refers to mortality that occurs prior to when
gear is brought on-board or alongside the vessel, and post-release
mortality, which refers to mortality that results from fishing activity
but occurs sometime after the animal is released alive. For sharks in
general, discard mortality can be significantly affected by a variety
of factors, including soak times, gear type, and water temperatures,
and shark size and sex (Ellis et al. 2017). For tope sharks in
particular, available data indicates that discard mortality rates are
highly variable. For instance, at-vessel mortality of tope sharks in
gillnets was estimated at 2 percent to 70 percent (6-6.5'' mesh, mean
soak time of 8.2 hours, fishing depth 17-130 m; n = 187; Walker et al.
2005) and 73 percent (4-8'' mesh, 2.4-20.6 hour soak time, fishing
depths of 9-230 m; n = 1,308; Braccini et al. 2012). At-vessel
mortality in longline gear has been reported as 0 percent (soak times
~6 hours, n = 5; Megalofonou et al., 2005; soak times ~13 hours, n =
25, Coelho et al. 2012) and 25 percent for demersal automatic longlines
(Rogers et al. 2017). Post-release mortality in gillnets has been
estimated at approximately 50 percent (Braccini et al. 2012).
Tope sharks are internationally traded, largely for meat (Dent and
Clarke et al. 2015), although their fins have been documented in
markets of China's Hong Kong Special Administrative Region (SAR) and
Singapore, both of which are major trade hubs for shark fins and other
shark products (Fields et al. 2018; Carde[ntilde]osa et al. 2022;
Saigal et al. 2024). However, tope shark fins were found to have a
relatively low incidence of occurrence in sampled markets, and tope
shark is not considered a premium value species in Hong Kong SAR
(Fields et al. 2018; Carde[ntilde]osa et al. 2022). Species-specific
trade records are extremely limited for shark meat; however, a recent
analysis by MacNeil et al. (2025) estimated the median annual trade of
tope shark meat at 3,002 mt (90 percent posterior density: 1,383-5,938
mt). The ``smooth-hounds, dogfish, tope'' group of sharks (which
includes at least 17 species) was characterized as highly export-
oriented, with approximately 78 percent of global landings being
exported, primarily to Europe and Australia (MacNeil et al. 2025). The
team concluded, and we concur, that trade in tope shark meat, and to a
lesser extent, fins, is one driver of overutilization. Further
discussion of shark fin and meat trade is provided in section 4.3 of
the Status Review Report.
Additional discussion of the threat of overutilization and fishing
practices, which vary by region, is provided for each DPS in later
sections of this document.

Disease and Predation

Tope sharks host numerous parasites throughout their range,
including various ectoparasitic flatworms (class Monogenea), isopods
(Aega serricauda), copepods (class Copepoda), and marine leeches
(Branchellion lobata), as well as endoparasitic flatworms (class
Cestoda, class Nematoda, Staphylorchis pacificus), cnidarians
(Ceratomyxa sphaerulosa, Chloromyxum ovatum), and acanthocephalans
(Corynosoma spp.) (see Pollersp[ouml]ck and Straube 2025). However, to
the extent that the host-parasite interactions have been described for
tope sharks, there is no indication that any of the observed parasites
affect tope sharks with the prevalence or virulence that would
constitute a significant threat to the survival of the species. The
team was unable to find any information about viral or microbial
diseases in tope sharks.
Several studies have reported on observed tope shark predation,
mostly by other elasmobranchs and occasionally by marine mammals.
Broadnose sevengill sharks (Notorhynchus cepedianus) are considered one
of the main predators of tope sharks, as they co-occur in all regions
except the NE Atlantic (Olsen 1984; Stevens and West 1997; Fowler et
al. 2005; Lucifora et al. 2005, 2006). Stevens and West (1997) found
that sevengill sharks were the most likely predator of juvenile tope
sharks in known nursery areas in Tasmania, but did not find evidence
that predation rates were particularly high. Tope sharks are also
considered a primary prey item for white sharks in South Africa (Fisher
2021) and have been observed being hunted and consumed by grey seals in
Northern Ireland (Jones et al. 2021). However, as with parasites and
disease, there is no indication that predation constitutes a
significant threat to the survival of the species.

Inadequacy of Existing Regulatory Mechanisms

Given the global distribution and migratory nature of tope sharks
within the range of each DPS, as well as the species' high degree of
population structuring, regulatory mechanisms at different spatial
scales are needed for adequate management, particularly with respect to
harvest and trade.
Several international agreements form the basis for global
cooperation on the conservation and management of the tope shark. The
Convention on the Conservation of Migratory Species of Wild Animals
(CMS) is an environmental treaty of the UN that aims to conserve
migratory species, their habitats, and their migration routes. Nearly
all of the countries within the geographic range of G. galeus are
Parties to the CMS; although, notable exceptions include the United
States, Canada, and Mexico. Tope sharks were listed under Appendix II
of CMS in 2020, thereby obligating Parties to work regionally to
promote their conservation. The CMS defines Appendix II species as
``those that have an unfavorable conservation status and that require
international agreements for their conservation and management, as well
as those that have a conservation status which would significantly
benefit from the international cooperation that could be achieved by an
international agreement.'' The primary instrument for achieving
international cooperation for sharks under CMS is the Memorandum of
Understanding on the Conservation of Migratory Sharks (Sharks MOU), a
non-binding global agreement established in 2010 that aims to maintain
a favorable conservation status for migratory sharks based on the best
available scientific information and taking into account the socio-
economic value of these species. In 2023, the tope shark was added to
Annex 1 of the Sharks MOU, which includes species that have an
unfavorable conservation status and that require international
agreements for their conservation or would benefit significantly from
such an agreement. The current 49 signatories to the Sharks MOU aim to
better understand migratory shark and ray populations, ensure
sustainability of fisheries, protect critical habitats, increase public
awareness, and enhance regional and international cooperation.
The Convention on International Trade in Endangered Species of Wild
Fauna and Flora (CITES) is a legally-binding international agreement
that aims to ensure that international trade in wild animals and plants
does not threaten their survival. Its primary tool

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for achieving this goal is through the listing of species in one of
three Appendices, which subjects their trade to certain regulations
depending on the degree of protection that the species needs. The tope
shark was listed on Appendix II of CITES during the 20th Conference of
the Parties (CoP20) in November/December 2025. Appendix II includes
species not necessarily threatened with extinction, but for which trade
must be controlled to ensure utilization is compatible with their
survival. This listing will go into effect June 5, 2027. International
trade in specimens of the species will be allowed with an export
permit, re-export certificate, or introduction from the sea (IFS)
certificate granted by the proper management authority. The above
permits or certificates may be granted if the trade is found to be
nondetrimental to the survival of the species in the wild and the
specimen was found to have been legally acquired. An IFS certificate
applies when a specimen is taken on the high seas (not under the
jurisdiction of any state) and is landed in a state. The recent listing
of the species on Appendix II should help to ensure the sustainability
of tope shark fisheries by regulating international trade in their
parts and products, largely their meat.

Other Natural or Manmade Factors Affecting Its Continued Existence

Because they generate electromagnetic fields (EMFs), undersea power
cables have been identified as a potential concern for marine organisms
that rely on electroreception and/or magnetoreception to perform basic
life functions like orienting, navigating, and locating prey or
predators. The IUCN Red List assessment for the tope shark (i.e.,
Walker et al. 2020) specifically mentions high-voltage undersea cables
as an indirect source of mortality that may affect feeding and
navigation of tope sharks. However, no studies are cited to support the
statement in the IUCN assessment and specific studies with respect to
how tope sharks may rely on natural electrical or magnetic signals and
how EMFs may impact their behaviors appear to be unavailable. Although
more research is needed, the research available to date has not
indicated that EMFs pose more than a negligible or minor impact on
marine fishes (Kavet et al. 2016, U.S. Offshore Wind Synthesis of
Environmental Effects Research (SEER) 2022).

Summary and Analysis of Section 4(a)(1) Factors for the NE Atlantic DPS

The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range

The assessment of this threat focused on projected impacts on tope
shark habitat over the foreseeable future from changes in environmental
conditions, in particular the impact of increased ocean temperatures.
Ocean temperature appears to be an important driver of tope shark
distributions (Klippel et al. 2016), and significant changes in
temperature could affect the future availability of suitable habitat.
Available literature also suggests that tope shark habitat may be
influenced by other variables, such as precipitation and salinity (Baez
et al. 2016, Tunnah et al. 2016; Morash et al. 2016), but the impact of
changes in these environmental variables on habitat for the NE Atlantic
DPS is unclear.
Despite the likely importance of ocean temperatures on tope shark
habitat, this threat was assigned a partial rating of Very Low based on
available evidence indicating that the net effect of changing
environmental conditions on the availability of suitable habitat for
this DPS may be neutral or even positive over the foreseeable future.
In particular, a 13.6 percent (239,103 sq. km) increase in suitable
habitat area for the NE Atlantic DPS is projected under future ocean
conditions. Analyses also indicate a likely poleward shift in habitat,
with potential losses in the southern part of the range (e.g., the
Mediterranean Sea and off Northwest Africa) being more than offset by
substantial projected habitat gains in the North Atlantic. Based on
this, the team concluded that habitat curtailment as a result of
changing environmental conditions is likely not a significant threat to
this DPS by itself currently or in the foreseeable future.
Several limitations of the results of the habitat suitability model
were noted, however, including its inability to account for various
ecological and behavioral factors that may influence habitat use by
tope sharks in the future under changed ocean conditions. The model,
which uses tope shark occurrence data and seven environmental data
layers (depth, surface and bottom sea temperature, salinity, primary
productivity, dissolved oxygen, sea ice concentration, and distance to
land) to project future suitable habitat, does not account for
migratory behaviors, intra-specific variation, or altered ecological
interactions. In addition, the relatively coarse scale of the habitat
suitability model could mask more nuanced impacts of warming in
nearshore nursery and pupping areas, which are more susceptible to
extreme temperature swings and salinity changes. More severe and/or
more frequent warming events in these shallower, coastal areas could
elevate metabolic rates in young-of-year and juveniles tope sharks,
potentially compromising their growth and energy reserves during a
critical stage of development. Given these other considerations, the
team ultimately concluded that changing environmental conditions may,
in combination with other factors, contribute to the extinction risk of
the NE Atlantic DPS over the foreseeable future; and therefore, they
adjusted the rating of this threat to Very Low/Low. In summary, the
mixed Very Low/Low score reflects the available evidence indicating no
physical loss of suitable habitat across the range of this DPS and the
potential, though uncertain, impacts on growth and development of
juveniles within coastal nursery areas.
The team also assigned a Very Low/Low rating to habitat threats
stemming from coastal development and pollution. This rating reflects
the conclusion that habitat destruction from coastal development and
pollution are not likely contributing significantly to extinction risk
for the NE Atlantic DPS and acknowledgement that impacts to more
sensitive coastal habitats may, in combination with other factors,
contribute to long-term extinction risk. The team did not find any
information about known or potential impacts of coastal development on
tope sharks in the NE Atlantic specifically. The team instead discussed
and considered evidence from the SW Pacific, where coastal development
and habitat degradation were cited as a possible cause for observed
declines in juvenile tope shark abundance in Australian nursery areas
(TSSC 2009; Stevens and West 1997), and whether this may inform their
assessment of potential impacts of coastal development on juvenile tope
sharks in this DPSs. However, as acknowledged in that particular case,
causal links were not established, and thus it is unclear what aspects
of coastal development or habitat modification may have played a role
in the observed decline in abundance of juvenile tope sharks.
With respect to pollution, bioaccumulation of contaminants is well
documented in tope sharks, but evidence of any consequences on tope
shark health and survival is lacking. Even in more remote areas, such
as the Azores, tope sharks have been found to

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bioaccumulate heavy metals like mercury and arsenic (Torres et al.
2014); however, results of available studies suggest that tope sharks
may have some capacity to limit toxic effects of mercury (e.g., Bonwick
et al. 1990). The team also acknowledged that plastics, which are
fairly ubiquitous in the marine environment, have been documented in
the stomach of a tope shark captured in the English Channel. However,
as no data are available regarding the rates of plastics ingestion by
tope sharks or the resulting health consequences, they viewed the
available data as insufficient to further assess this potential threat.
In summary, there is very little information regarding the threat
of coastal development and pollution to the NE Atlantic DPS. There is
concern that this threat could disproportionately affect early life
stages and may contribute to the long-term extinction risk of the NE
Atlantic DPS in combination with other factors; however, the available
information is not sufficient to conclude that this threat is likely to
contribute by itself to the long-term or near future risk of extinction
of the NE Atlantic DPS.

Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes

The threat of overutilization for the NE Atlantic DPS was assigned
a rating of Low/Moderate, largely due to the ongoing but greatly
reduced level of bycatch within the region. Although there are no
directed commercial fisheries for the species within the NE Atlantic
and recreational catch appears to be limited, tope sharks continue to
be bycaught in commercial trawl, gillnet, and longline fisheries within
the region.
Historical landings data for this region are considered unreliable
due to under-reporting, species misidentifications, and the aggregation
of shark landings into generic categories (like ``dogfish'' or
``hound'') by many countries. The team concluded that the lack of any
stock assessment and robust fishing effort data prevent a clear
understanding of the level to which overutilization of this DPS of tope
sharks may have occurred historically or is occurring currently.
Within this region, the North Sea, Irish Sea, English Channel, Bay
of Biscay, waters off Spain and Portugal, waters off the northwest
coasts of Scotland and Ireland, and waters around the Azores (subareas
4 and 6-10 of FAO Fishing Area 27) are considered the most important in
terms of both tope shark occurrence and fishing activity. As there has
been no directed tope shark fishery in these waters, the annual
commercial catch estimates (live weight equivalent of landings,
discards excluded) provided by the 20 ICES member countries reflect
bycatch landed from other trawl, gillnet, and longline fisheries in the
region (ICES 2023). Although some historical species-specific landings
data are available, prior to 2005 many countries did not report
species-specific shark landings (ICES 2022). Based on available,
species-specific data, over the past 10 years, the highest capture
volumes of tope shark have been reported by France, typically followed
by Spain and then Portugal (see Figure 4-8 in Status Review Report).
During 2018-2021, France accounted for about 78 percent of the reported
landings, and in 2022, accounted for about 74 percent of the reported
landings (ICES 2023a). Tope sharks are landed in French mixed fisheries
operating mainly in the English Channel and Celtic Seas (Bonfil 1994;
ICES 2023a; see Figure 4-9 in Status Review Report). In the 1980s, tope
sharks ranked as France's third most important commercial shark
species, comprising 6 percent of shark landings, much of which was used
domestically or exported to Italy (Bonfil 1994). However, France's
export of tope shark to Italy declined after 1983 as a result of
mercury contamination (Vannuccini 1999). Reported landings for France
peaked in 1979 at 2,335 mt, which is an order of magnitude greater than
current landings levels (ICES 2023a; see Figures 4-6 and 4-9 in Status
Review Report). Landings reported for the early 1990s, which ranged
from 279 to 408 mt per year, are similar to France's more recent
landings data (i.e., during 2005-2021), which have remained relatively
consistent from year to year. Landings reported by Spain have declined
since 2005, and some of the more recent decline may be attributable to
management restrictions enacted in 2015 as well as missing data (ICES
2023a). Landings for Portugal, which primarily captures tope sharks in
waters around the Azores (FAO subarea 10.a.2), fluctuated without a
clear trend during 2005-2022 (see Figure 4-8 in Status Review Report).
Portugal's lowest reported landings occur in 2019-2022, which may be
attributable in part to the COVID-19 pandemic (ICES 2023a).
Around the Azores (within FAO subarea 10.a.2), tope sharks are
landed as bycatch in mainly the swordfish (Xiphias gladius) fishery and
the demersal longline fishery, and by recreational hand and pole lines
(Santos et al. 2020). A review of landings data for this subarea from
1990 to 2018 by Santos et al. (2020) showed a decreasing trend in
annual landings of tope sharks from 1998/2000 to 2009, followed by a
small increase during 2010-2017 (see Figure 3-5 in Status Review
Report). The estimated standardized CPUE (kg 10-3 hooks)
fluctuates during the early 1990s but remains fairly stable over the
remainder of the time period. Santos et al. (2020) hypothesized that
the overall decrease in annual landings relative to the 1990s reflects
an increased discard rate, which they suspected was driven by low
market demand, both in domestic and in international markets, as well
as management measures. Discard data for tope sharks necessary to
verify this hypothesis are not available.
Within the Mediterranean (FAO Fishing Area 37), tope sharks have
been commercially fished since at least 1985; however, there are
limited historical landings data, particularly because much of the
fishing was artisanal, and such landings were rarely reported or are
otherwise difficult to find (Ferretti et al. 2005). Fishing for tope
sharks in the Mediterranean has been prohibited since 2014 and
reporting of incidental capture of tope sharks to the Regional
Fisheries Management Organization (RFMO) for the Mediterranean, the
General Fisheries Commission for the Mediterranean (GFCM), is required
for member countries; however, data on incidental catch of covered
sharks and rays by fishery and gear type is limited (GFCM 2018). Tope
sharks are now taken as bycatch, primarily in commercial drift (i.e.,
surface) longlines targeting tunas (Thunnus spp.) or swordfish (Xiphias
gladius), and occasionally in small-scale fisheries, which commonly
employ longlines and trammel and gill nets (Carpentieri et al. 2021).
More rarely, tope sharks have also been reported as incidental catch in
bottom otter trawls and small-scale set net fisheries (Carpentieri et
al. 2021). The number of vessels participating in the bottom trawl
fishery has declined since about the year 2000, and at least within the
western Mediterranean, bottom trawling effort has shifted from the
shelf into deeper waters to target high value shellfish (Ramirez-Amaro
et al. 2020).
Overall, the frequency of tope shark bycatch in the Mediterranean
appears to be moderate to low relative to other elasmobranchs. During
2000-2020, across all fisheries, tope sharks comprised 6.2 percent (by
number) of the reported incidental catch of elasmobranch species
(~2,339 sharks) in the Mediterranean, whereas the two most commonly
bycaught elasmobranchs, the sandbar shark (Carcharhinus plumbeus) and
the smooth-hound shark (Mustelus mustelus), comprised 20.9 percent and

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15.9 percent of the reported catch, respectively (FAO 2020). Based on
data for the westernmost portion of the Mediterranean (FAO Fishing Area
37.1.1), landings gradually increased to a maximum of nearly 50 mt in
2011, but then sharply declined in 2015-2016 and have remained below 5
mt per year since 2017 (see section 4.3.1.1. in Status Review Report).
Landings data are even more limited for the eastern central
Atlantic portion of this DPS's range (i.e., FAO Fishing Area 34), and
appear to be available only from the year 2000 onward for three
countries (Morocco, Portugal, and Spain). Based on the available data,
total annual tope shark catch never exceeds 125 mt in this area and
exhibits no clear trend.
Overall, the commercial landings of tope shark within the NE
Atlantic region show a substantial decline since the 1980s and a
moderate decline from 2005 to 2022, but appear fairly stable in recent
years (see Figure 4-13 in Status Review Report). Large declines in tope
shark landings ~10-15 years ago indicated in some of the available
datasets could potentially reflect a collapse in tope shark abundance
as a result of overexploitation. However, given concerns with data
reliability and the lack of fisheries-independent abundance estimates
or sufficient fishing effort data, the team had low confidence in
making inferences based on trends in landings data. Interpretation of
the available landings data is further complicated by the enactment of
various management measures across the region for sharks and for tope
sharks, in particular. For example, following a 2008 prohibition on
commercial tope fishing by the UK, the proportion of tope sharks
discarded by English and Welsh gillnet fisheries increased
significantly, rising from 11 percent (2002-2007) to 67 percent (2008-
2016) (Silva and Ellis 2019). Other notable measures include
Recommendation GFCM/36/2012/3, which as of 2014, prohibited the
retention, sale, and landing of tope sharks in the Mediterranean Sea;
and Regulation EU 2015/104, which as of 2015, prohibited targeting and
retention of tope sharks taken by longlines throughout most of the NE
Atlantic. Some portion of the observed decline in tope shark landings
is undoubtedly attributable to these management measures; however,
ongoing bycatch in some fisheries, issues with generic labeling of
shark landings, and an unknown level of discard mortality, prevent an
accurate measure of the reduction in the threat of overutilization.
The team also noted that despite lower reported landings and
existing regulatory protections, total tope shark landings have
consistently exceeded the precautionary catch limits advised by ICES,
often by a substantial amount. For the years 2024-2027, ICES advised
that total annual landings not exceed 241 mt per year, but recent
reported landings have been around 500 mt (ICES 2023a). In addition,
the species' life history characteristics (e.g., low productivity, late
age-at-maturity) likely exacerbate this threat or slow the DPS's
ability to rebound from historically higher levels of exploitation.
Ultimately, the team assigned a Low/Moderate rating to this threat
to reflect the mixed evidence regarding the level of extinction risk
posed by commercial fishing in the long and near-terms. Two team
members found that, while the consistent exceedance of the
precautionary catch limits advised by ICES suggests that
overutilization of tope sharks may be occurring, there is insufficient
evidence to conclude that overutilization is occurring in this region
such that it poses an extinction risk to the DPS. Thus, these team
members concluded that the available data are not sufficient to find
that this threat, on its own, likely contributes significantly to the
long-term or near future extinction risk of the NE Atlantic DPS, but it
may in combination with other factors. One team member placed greater
weight on indicators of historical overutilization and ongoing
exceedance of advised catch limits to reach the conclusion that this
threat is contributing to the long-term risk of extinction; thus, this
team member assigned a Moderate rating to this threat. Given the
limited confidence in the relevant, available data, the team agreed on
a rating of ``low sufficiency'' for the available data, and
consequently the ratings are based on best professional judgment and
interpretation of the available information. This threat is discussed
in more detail in section 4.3.1 of the Status Review Report.

Disease and Predation

This threat category was assigned a Very Low rating, reflecting
agreement that, based on the best available information, neither
disease nor predation is contributing significantly to the extinction
risk of the NE Atlantic DPS now or over the foreseeable future.
Regarding disease, the team noted that while tope sharks are known
to host a wide variety of parasites, there is no indication that any of
these affect tope sharks with the prevalence or virulence such that
they pose an extinction risk to the DPS--either

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