Proposed Rule2022-21605
Endangered and Threatened Wildlife and Plants; Endangered Species Status for the San Francisco Bay-Delta Distinct Population Segment of the Longfin Smelt
Primary source
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Published
October 7, 2022
Issuing agencies
Interior DepartmentFish and Wildlife Service
Abstract
We, the U.S. Fish and Wildlife Service (Service), propose to list the San Francisco Bay-Delta distinct population segment (DPS) of longfin smelt (Spirinchus thaleichthys) (Bay-Delta longfin smelt), a fish species of the Pacific Coast, as an endangered species under the Endangered Species Act of 1973, as amended (Act). After a review of the best scientific and commercial information available, we find that listing the DPS is warranted. Accordingly, we propose to list the Bay- Delta longfin smelt DPS as an endangered species under the Act. If we finalize this rule as proposed, it would add this DPS to the List of Endangered and Threatened Wildlife and extend the Act's protections to the DPS. We also find that the designation of critical habitat for the Bay-Delta longfin smelt is not determinable at this time.
Full Text
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[Federal Register Volume 87, Number 194 (Friday, October 7, 2022)]
[Proposed Rules]
[Pages 60957-60975]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-21605]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R8-ES-2022-0082; FF09E21000 FXES1111090FEDR 223]
RIN 1018-BG07
Endangered and Threatened Wildlife and Plants; Endangered Species
Status for the San Francisco Bay-Delta Distinct Population Segment of
the Longfin Smelt
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
list the San Francisco Bay-Delta distinct population segment (DPS) of
longfin smelt (Spirinchus thaleichthys) (Bay-Delta longfin smelt), a
fish species of the Pacific Coast, as an endangered species under the
Endangered Species Act of 1973, as amended (Act). After a review of the
best scientific and commercial information available, we find that
listing the DPS is warranted. Accordingly, we propose to list the Bay-
Delta longfin smelt DPS as an endangered species under the Act. If we
finalize this rule as proposed, it would add this DPS to the List of
Endangered and Threatened Wildlife and extend the Act's protections to
the DPS. We also find that the designation of critical habitat for the
Bay-Delta longfin smelt is not determinable at this time.
DATES: We will accept comments received or postmarked on or before
December 6, 2022. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59
p.m. Eastern Time on the closing date.
We must receive requests for a public hearing, in writing, at the
address shown in FOR FURTHER INFORMATION CONTACT by November 21, 2022.
ADDRESSES: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>. In the Search box, enter FWS-R8-ES-2022-0082,
which is the docket number for this proposed rule. Then, click on the
Search button. On the resulting page, in the panel on the left side of
the screen, under the Document Type heading, check the Proposed Rule
box to locate this document. You may submit a comment by clicking on
``Comment.''
(2) By hard copy: Submit by U.S. mail to: Public Comments
Processing, Attn:
[[Page 60958]]
FWS-R8-ES-2022-0082, U.S. Fish and Wildlife Service, MS: PRB/3W, 5275
Leesburg Pike, Falls Church, VA 22041-3803.
We request that you send comments only by the methods described
above. We will post all comments on <a href="https://www.regulations.gov">https://www.regulations.gov</a>. This
generally means that we will post any personal information you provide
us (see Information Requested, below, for more information).
FOR FURTHER INFORMATION CONTACT: Donald Ratcliff, Field Supervisor,
U.S. Fish and Wildlife Service, San Francisco Bay-Delta Fish and
Wildlife Office, 650 Capitol Mall Suite 8-300, Sacramento, CA 95814;
telephone 916-930-5603. Individuals in the United States who are deaf,
deafblind, hard of hearing, or have a speech disability may dial 711
(TTY, TDD, or TeleBraille) to access telecommunications relay services.
Individuals outside the United States should use the relay services
offered within their country to make international calls to the point-
of-contact in the United States.
SUPPLEMENTARY INFORMATION:
Information Requested
We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and as effective as possible. Therefore, we request
comments or information from other governmental agencies, Native
American Tribes, the scientific community, industry, or any other
interested parties concerning this proposed rule.
We particularly seek comments concerning:
(1) The DPS's biology, range, and population trends, including:
(a) Biological or ecological requirements of the DPS, including
habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current population levels, and current and
projected trends; and
(d) Past and ongoing conservation measures for the DPS, its
habitat, or both.
(2) Factors that may affect the continued existence of the DPS,
which may include the present or threatened destruction, modification,
or curtailment of its habitat or range, overutilization, disease,
predation, the inadequacy of existing regulatory mechanisms, or other
natural or manmade factors.
(3) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to this DPS and existing regulations that
may be addressing those threats.
(4) Additional information concerning the historical and current
status of this DPS.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Please note that submissions merely stating support for, or
opposition to, the action under consideration without providing
supporting information, although noted, do not provide substantial
information necessary to support a determination. Section 4(b)(1)(A) of
the Act directs that determinations as to whether any species is an
endangered or a threatened species must be made solely on the basis of
the best scientific and commercial data available.
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in ADDRESSES. We request that you
send comments only by the methods described in ADDRESSES.
If you submit information via <a href="https://www.regulations.gov">https://www.regulations.gov</a>, your
entire submission--including any personal identifying information--will
be posted on the website. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this information from public
review. However, we cannot guarantee that we will be able to do so. We
will post all hardcopy submissions on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Because we will consider all comments and information we receive
during the comment period, our final determination may differ from this
proposal. Based on the new information we receive (and any comments on
that new information), we may conclude that the DPS is threatened
instead of endangered, or we may conclude that the DPS does not warrant
listing as either an endangered species or a threatened species.
Public Hearing
Section 4(b)(5) of the Act provides for a public hearing on this
proposal, if requested. Requests must be received by the date specified
in DATES. Such requests must be sent to the address shown in FOR
FURTHER INFORMATION CONTACT. We will schedule a public hearing on this
proposal, if requested, and announce the date, time, and place of the
hearing, as well as how to obtain reasonable accommodations, in the
Federal Register and local newspapers at least 15 days before the
hearing. We may hold the public hearing in person or virtually via
webinar. We will announce any public hearing on our website, in
addition to the Federal Register. The use of virtual public hearings is
consistent with our regulations at 50 CFR 424.16(c)(3).
Previous Federal Actions
On April 2, 2012, we published a 12-month finding on the status of
the Bay-Delta longfin smelt (77 FR 19756), which concluded that the
population of longfin smelt in the San Francisco Bay-Delta was a valid
DPS and was warranted for listing under the Act. However, our
completion of a proposed rule to amend the List of Endangered and
Threatened Wildlife was precluded by higher priority actions. As a
result, the Bay-Delta longfin smelt was added to our candidate species
list. During the interim period between the DPS becoming a candidate
and this proposed rule, we addressed its status through our annual
candidate notices of review.
Supporting Documents
A species status assessment (SSA) team prepared an SSA report for
the Bay-Delta longfin smelt (Service 2022, entire). The SSA team was
composed of Service biologists and State resource agency staff, who
then consulted with other scientific experts during the development of
the SSA report. The SSA report represents a compilation of the best
scientific and commercial data available concerning the status of the
DPS, including the impacts of past, present, and future factors (both
detrimental and beneficial) affecting the DPS and its habitat. In
accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), and our August 22,
2016, memorandum updating and clarifying the role of peer review of
listing actions under the Act, we sought the expert opinions of five
appropriate specialists regarding the SSA. We received three responses.
The SSA report and other materials related to this proposed rule can be
found at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R8-ES-2022-
0082.
I. Proposed Listing Determination
Distinct Population Segment
As stated above, on April 2, 2012, we concluded that the population
of longfin smelt in the San Francisco Bay-Delta was a valid DPS and was
warranted for
[[Page 60959]]
listing under the Act (77 FR 19756). Since that time, additional
genetic information has become available to further support our DPS
conclusion that the population is both discrete and significant
(Sa[gbreve]lam et al. 2021, p. 1793; Service 2022, chapter 2). Below is
a summary of our conclusions regarding discreteness and significance
for the San Francisco Bay-Delta population of the longfin smelt. For
more background and details of our analysis see the 2012 12-month
finding (77FR 19756).
Discreteness
Because of its limited swimming capabilities and because of the
great distances between the San Francisco Bay-Delta and known breeding
populations to the north, we conclude that the San Francisco Bay-Delta
population is markedly separated from other longfin smelt populations,
and thus meets the discreteness element of the 1996 DPS policy. The
best available information indicates that longfin smelt from the San
Francisco Bay-Delta population complete their life cycle moving between
freshwater, brackish water, and saltwater portions of the estuary and
nearby coastal ocean waters in the Gulf of Farallones. The nearest
known breeding population of longfin smelt is Humboldt Bay, 420 km (260
mi) north of the San Francisco Bay-Delta. As a result, potential
interchange between the San Francisco Bay-Delta population and other
longfin smelt breeding populations is limited. Although the best
scientific information suggests that potential movement of longfin
smelt northward from the San Francisco Bay-Delta would be facilitated
by ocean currents, potential movement from more northern estuaries
south to the San Francisco Bay-Delta would be more difficult and
unlikely because of ocean currents. Based on our review of the best
scientific and commercial information available, we conclude that the
San Francisco Bay-Delta population of longfin smelt is markedly
separated from other longfin smelt populations as a consequence of
physical, physiological, ecological, or behavioral factors.
Significance
We conclude that the San Francisco Bay-Delta population is
biologically significant to the longfin smelt species because the
population occurs in an ecological setting unusual or unique for the
species and its loss would result in a significant truncation of the
range of the species. The San Francisco Bay-Delta longfin smelt
population occurs at the southern edge of the species' range and has
likely experienced different natural selection pressures than those
experienced by populations in middle and more northern portions of the
species' range. The population may therefore possess unique
evolutionary adaptations important to the conservation of the species.
The San Francisco Bay-Delta also is unique because it is the largest
estuary on the Pacific Coast of the United States. Because of its large
size and diverse aquatic habitats, the San Francisco Bay-Delta has the
potential to support a large longfin smelt population and is thus
potentially important in the conservation of the species. The San
Francisco Bay-Delta population also is significant to the taxon because
the nearest known breeding population of longfin smelt is hundreds of
miles away, so loss of the San Francisco Bay-Delta population would
significantly truncate the range of the species and result in a
significant gap in the species' range. Based on our review of the best
available scientific and commercial information, we conclude that the
San Francisco Bay-Delta population meets the significance element of
the 1996 DPS policy.
Determination of Distinct Population Segment
Because we have determined that the San Francisco Bay-Delta
population meets both the discreteness and significance elements of the
1996 DPS policy, we find that the San Francisco Bay-Delta longfin smelt
population is a valid DPS and thus is a listable entity under the Act.
As a result, we continue to find that the San Francisco Bay-Delta DPS
of the longfin smelt meets the standards for determination as a DPS
under our 1996 DPS policy (61 FR 4722).
Background
Below is a summary of biological information regarding the Bay-
Delta longfin smelt. A thorough description and review of the range,
life history, and ecology of the Bay-Delta longfin smelt is presented
in the SSA report (Service 2022, entire).
Description and Distribution: The longfin smelt is a small fish
species 9-11 centimeters (cm) (3.5-4.3 inches (in)) in length with a
relatively short lifespan of approximately 2 to 3 years. The longfin
smelt, as a species, occurs in bays and estuaries from northern
California north along the coast through Alaska. The Bay-Delta longfin
smelt occupies the San Francisco Bay Estuary and areas of the Pacific
Ocean out to the Farallon Islands (see figure 1). The tidally
influenced San Francisco Bay Estuary includes the central and south San
Francisco Bay, Suisun Bay, and San Pablo Bay, and the Sacramento and
San Joaquin River Delta (Delta). Longfin smelt in the San Francisco
Bay-Delta are pelagic fish (fish most frequently occurring in open-
water habitats) that exhibit a facultatively anadromous life history,
meaning older juveniles and adults can migrate to the ocean, but are
required to return to fresh water for spawning and rearing (Moyle 2002,
p. 236). Bay-Delta longfin smelt spawn only once in their lifetime but
may have multiple spawning events during the spawning season (generally
late fall to early spring) (Service 2022, p. 12). Reproduction occurs
in low-salinity to freshwater habitats beginning in late fall/early
winter and extends into the spring as water temperature and low-
salinity conditions allow (Service 2022, pp. 11-13).
[[Page 60960]]
[GRAPHIC] [TIFF OMITTED] TP07OC22.000
Regulatory Framework
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species is an endangered species or a threatened species. The
Act defines an ``endangered species'' as a species that is in danger of
extinction throughout all or a significant portion of its range, and a
``threatened species'' as a species that is likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range. The Act requires that we determine
whether any species is an endangered species or a threatened species
because 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.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we must evaluate all
identified threats by considering the species' expected response and
the effects of the threats--in light of those actions and conditions
that will ameliorate the threats--on an individual, population, and
species level. We evaluate each threat and its expected effects on the
species, then analyze the cumulative effect of all of the threats on
the species as a whole. We also consider the cumulative effect of the
threats in light of those actions and conditions that will have
positive effects on the species, such as any existing regulatory
mechanisms or conservation efforts. The Secretary determines whether
the species meets the definition of an ``endangered species'' or a
``threatened species'' only after conducting this cumulative analysis
and describing the expected effect on the species now and in the
foreseeable future.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' Our
implementing regulations at 50 CFR 424.11(d) set forth a framework for
evaluating the foreseeable future on a case-by-case basis. The term
[[Page 60961]]
``foreseeable future'' extends only so far into the future as we can
reasonably determine that both the future threats and the species'
responses to those threats are likely. In other words, the foreseeable
future is the period of time in which we can make reliable predictions.
``Reliable'' does not mean ``certain''; it means sufficient to provide
a reasonable degree of confidence in the prediction. Thus, a prediction
is reliable if it is reasonable to depend on it when making decisions.
It is not always possible or necessary to define the foreseeable
future as a particular number of years. Analysis of the foreseeable
future uses the best scientific and commercial data available and
should consider the timeframes applicable to the relevant threats and
to the species' likely responses to those threats in view of its life-
history characteristics. Data that are typically relevant to assessing
the species' biological response include species-specific factors such
as lifespan, reproductive rates or productivity, certain behaviors, and
other demographic factors.
Analytical Framework
The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data available
regarding the status of the DPS, including an assessment of the
potential threats to the DPS. The SSA report does not represent our
decision on whether the DPS should be proposed for listing as an
endangered or threatened species under the Act. However, it does
provide the scientific basis that informs our regulatory decisions,
which involve the further application of standards within the Act and
its implementing regulations and policies. The following is a summary
of the key results and conclusions from the SSA report; the full SSA
report can be found at Docket No. FWS-R8-ES-2022-0082 on <a href="https://www.regulations.gov">https://www.regulations.gov</a> and by contacting the Service's Bay-Delta Fish and
Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
To assess the Bay-Delta longfin smelt's viability, we used the
three conservation biology principles of resiliency, redundancy, and
representation (Shaffer and Stein 2000, pp. 306-310). Briefly,
resiliency supports the ability of the species to withstand
environmental and demographic stochasticity (for example, wet or dry,
warm or cold years), redundancy supports the ability of the species to
withstand catastrophic events (for example, droughts, large pollution
events), and representation supports the ability of the species to
adapt over time to long-term changes in the environment (for example,
climate changes). In general, the more resilient and redundant a
species is and the more representation it has, the more likely it is to
sustain populations over time, even under changing environmental
conditions. Using these principles, we identified the DPS's ecological
requirements for survival and reproduction at the individual,
population, and DPS level and described the beneficial and risk factors
influencing the DPS's viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated the DPS's life-history needs. The
next stage involved an assessment of the historical and current
condition of the DPS's demographics and habitat characteristics,
including an explanation of how the DPS arrived at its current
condition. The final stage of the SSA involved making predictions about
the DPS's responses to positive and negative environmental and
anthropogenic influences. Throughout all of these stages, we used the
best information available to characterize viability as the ability of
the DPS to sustain itself in the wild over time. We use this
information to inform our regulatory decision.
Summary of Biological Status and Threats
In the discussion below, we review the biological and resource
needs of the Bay-Delta longfin smelt, and the threats that influence
the DPS's current and future condition, in order to assess the DPS's
overall viability and the risks to that viability.
Species (DPS) Needs
Below is a summary of the Bay-Delta longfin smelt's biological and
ecological needs, more details of which can be found in the SSA report
(Service 2022, chapter 2 entire).
The needs of the Bay-Delta longfin smelt to successfully carry out
its life history are highly dependent on the freshwater inflow and
resulting temperature and environmental conditions and resources of the
San Francisco Bay estuary (comprising the San Francisco Bay, San Pablo
Bay, Suisun Bay, and the Sacramento and San Joaquin River Delta). The
amount and duration of freshwater input from rivers and tributaries
flowing into the estuary greatly influences the location and extent of
where the appropriate water temperature and saline conditions are
present for the DPS to carry out its life functions (Service 2022,
section 2.2, Ecological Setting, pp. 8-11). These freshwater flows can
be natural, such as in wet years or dry years, or as a result of human-
altered water management. Under high-flow conditions, the amount of
low-saline/cool-water habitat is more abundant, whereas under low-flow
conditions the availability, amount, extent, and duration of areas that
contain the appropriate habitat conditions for the Bay-Delta longfin
smelt are greatly reduced.
The needs of the Bay-Delta longfin smelt can be categorized into
three main resource needs and biological condition categories, and
include: (1) appropriate freshwater or low-saline water conditions; (2)
appropriate water temperature conditions; and (3) adequate food
resources and availability by life-stage. As the Bay-Delta longfin
smelt is subject to both freshwater and saline water conditions, its
habitat is extremely variable. These variable conditions along with
other factors exert a strong influence on the condition of the DPS's
food resources.
Interaction of Waterflow Conditions and Habitat
The San Francisco Bay estuary is one of the largest estuaries on
the West Coast of the continental United States (Sommer et al. 2007, p.
271). Everywhere freshwater flow enters the San Francisco Bay estuary,
it can generate variable freshwater and salinity conditions for plants
and animals, such as the Bay-Delta longfin smelt, that are adapted to
brackish water conditions. The San Francisco Bay estuary consists of
five areas: the Sacramento-San Joaquin River Delta, Suisun Bay, San
Pablo Bay in the north, as well as South San Francisco Bay and Central
San Francisco Bay in the South. The northern regions receive freshwater
input from the Sacramento-San Joaquin River systems, as well as lesser
inputs from the Napa, Sonoma, and Petaluma Rivers. In the north, the
prevailing direction of water flow is from east to west. In the south,
the Central San Francisco Bay receives little freshwater from its
mostly urbanized watersheds that are directly adjacent to the bay, and
the South San Francisco Bay receives some freshwater input from Alviso
Slough (Largier 1996, p. 69). We refer to these areas collectively as
the San Francisco Bay-Delta. The Sacramento-San Joaquin River systems
represent approximately 90 percent of the estuary's freshwater input,
and as such, have the largest influence on estuarine habitat conditions
(Jassby et al. 1995, p. 275, and fig. 4, p. 279; Monismith et al. 2002,
fig. 7, p. 3010). The southern part of San Francisco Bay is generally
characterized as a lagoonal system,
[[Page 60962]]
whereas the northern reaches function as a tidal river estuary due to
the much larger freshwater flow inputs (Kimmerer 2004, p. 7). However,
during large freshwater flow events and wet rainfall years, the small
tributaries can have important localized effects and support conditions
suitable for Bay-Delta longfin smelt spawning and larval rearing (Lewis
et al. 2019, p. 3).
Numerous studies have shown the positive correlation between Bay-
Delta longfin smelt juvenile abundance and freshwater flow (Stevens and
Miller 1983, pp. 431-432; Jassby et al. 1995, p. 285; Kimmerer 2002, p.
47; Rosenfield and Baxter 2007, p. 1585; Sommer et al. 2007, p. 274;
Kimmerer et al. 2009, p. 381; MacNally et al. 2010, p. 1422; Thomson et
al. 2010, pp. 1439-1440; Maunder et al. 2015, p. 108; and Nobriga and
Rosenfield 2016, p. 53). The survival of longfin smelt through their
early life-stages is lower during dry or low-flow conditions and higher
during wet or high-flow conditions--the evidence for this finding is
that Bay-Delta longfin smelt abundance indices nearly always decline
sharply during dry or low-flow periods and are higher in wet or high-
flow periods (Mahardja et al. 2021, pp. 9-10). As a result, freshwater
flows with appropriate magnitude, timing, and frequency (both
seasonally and annually) are a significant DPS need.
Low-salinity water is an important feature for the Bay-Delta
longfin smelt. Because the San Francisco Bay is connected to the
Pacific Ocean, saltwater tidal flows move upstream into the estuary and
mix with inflowing freshwater flows moving downstream. These tidal and
stream flows present opposing hydraulic forces that interact with each
other and the estuary's bathymetry (underwater contours and channels)
to create extremely variable and complex currents of vertical and
lateral hydrodynamic mixing of salt- and freshwater (Stacey et al.
2001, pp. 17026-17035). Depending on the strength of the tidal or
freshwater inflow, the area where the saltwater and freshwater interact
may move either upstream toward the Delta or downstream into the bays
toward the ocean. A common term that is used to refer to where this
estuarine mixing and low-salinity zone is located is ``X2''. X2 is the
distance in kilometers (km) from the Golden Gate (boundary between the
San Francisco Bay estuary and the Pacific Ocean) to the place where
salinity near the bottom of the water column is 2 practical salinity
units (PSU; also known as parts per thousand) (Jassby et al. 1995, pp.
274-275) (figure 2). Isohalines are lines (or contours) that join
points of equal salinity in an aquatic system.
[GRAPHIC] [TIFF OMITTED] TP07OC22.001
X2 is used in part because it represents the approximate upstream
limit of where surface and bottom salinity differ, and because
favorable turbidity conditions and high phyto- and zooplanktonic
abundances are broadly associated with it. Estuarine pelagic fishes,
including the Bay-Delta longfin smelt, are also associated with this
location due to it being the downstream limit of the low-salinity zone
for spawning and rearing and for this zone providing favorable
environmental conditions and abundance of food resources (Dege and
Brown 2004, fig. 3, p. 57).
The position of X2 is always moving as a result of freshwater or
tidal flows. This movement results in changes to the size, shape, and
ecological function of the low-salinity zone (MacWilliams et al. 2015,
figs. 11-12, p. 22). Tidal flows affect the position of X2 most
strongly over short time scales (hours to weeks) (Kimmerer 2004, fig.
2, p. 12). Over longer time scales, freshwater from the Sacramento-San
Joaquin Delta system has the dominant influence on the position of X2
in the estuary (Jassby et al. 1995, p. 275, and fig. 4, p. 279;
Monismith et al. 2002, fig. 7, p. 3010). The surface area of the low-
salinity zone (and, therefore, the habitat available for Bay-Delta
longfin smelt) increases very rapidly as it begins to include areas
within the San Pablo Bay (X2 <= 55 km (34 miles (mi)), resulting in
peak low-salinity zone areas of 150 to 250 square km (58 to 97 mi\2\)
(MacWilliams et al. 2015, fig. 12, p. 22).
Water Temperature
Bay-Delta longfin smelt require cool water conditions. Laboratory
and field studies and surveys have found that hatching success, size,
growth, and survivability of Bay-Delta longfin smelt are all closely
dependent on water temperatures near 15 degrees Celsius ([deg]C) (59
[deg]F ([deg]F)) or less. Water temperatures of 16 [deg]C (61 [deg]F)
are the upper limit for spawning, with temperatures of 13 [deg]C (55
[deg]F) and potentially lower being more ideal (Baxter 2016, entire;
Tempel and Burns 2021, slide 12; Service 2022, p. 21). Studies and
information have identified water temperatures near 20 [deg]C (68
[deg]F) as the upper limit for larval fish (Jeffries et al. 2016, p.
1709). The larvae rear during the spring in the low-salinity/cool-water
[[Page 60963]]
locations near where they were spawned and born. Adults and juveniles
have been found in water temperatures of less than 22 [deg]C (71
[deg]F) and likely spend the warmer periods of the year in cooler Bay
habitats and the coastal ocean to escape warming temperatures that
occur in much of the estuary during the summer. This movement is likely
part of the DPS's adaptive capacity and could be facilitated as water
temperatures rise toward 20 [deg]C (68 [deg]F) in the late spring.
Likewise, Bay-Delta longfin smelt adults have not been known to return
to most of the estuary until temperatures drop below 22 [deg]C (71
[deg]F) in the autumn.
Water temperatures within the estuary vary and depend on ambient
air temperatures and on the amount of freshwater inflow into the system
(Vroom et al. 2017, pp. 9918-9920). Because of California's
Mediterranean climate of cool wet winters and hot dry summers, the
majority of natural inflow and input of cooler freshwater (from cool-
season rains and snowmelt) into the estuary occurs in the late fall to
early spring, which coincides with the spawning period of the Bay-Delta
longfin smelt. The operation of the State Water Project and Central
Valley Project and the many large reservoirs that store and supply
water to agricultural and municipal beneficial uses modify the flow
regime and affect the volume and timing of delta freshwater inflow and
outflow. As freshwater flows decrease and water temperatures warm each
spring into early summer, the young fish (those >20 millimeter (mm)
(0.79 in) in length) move seaward, and many individuals (both juveniles
and adults) that are more tolerant of saline conditions move into the
Pacific Ocean during the late spring and summer months (Service 2022,
p. 17).
Food Resources
The diet of Bay-Delta longfin smelt is very specific and varies by
age class and location within the estuary. Bay-Delta longfin smelt
larvae select strongly for the calanoid copepod Eurytemora affinis as
their food resource. All other prey types combined account for only
about 10 percent of their diet (Barros et al. 2022, fig. 6a and 6c;
Service 2022, Section 2.5 Diet). When Bay-Delta longfin smelt reach
about 25 mm (1 in) in length, their diet switches and is nearly all
mysids, a taxonomic group of larger crustaceans commonly called opossum
shrimp (Barros et al. 2022, fig. 6b). This observation of a highly
specified diet applies to fresh- and brackish-water habitats throughout
the estuary (Barros et al. 2022, fig. 3). The peak abundances of these
food resources have been identified as being in the estuary's largest
low-salinity zone associated with X2 and generated by freshwater flow
from the Delta (Kimmerer et al. 1998, pp. 1701-1708; Kimmerer 2002,
fig. 2, p. 45). These factors explain the interrelatedness of flow with
key resource needs of the DPS--such that prey, salinity, and
temperature conditions facilitate the access of particular life stages
to habitat areas with sufficient food resources to meet the DPS's life-
history requirements.
Threats Influencing the Bay-Delta Longfin Smelt
The threats facing the Bay-Delta DPS of the longfin smelt include
habitat alteration (Factor A) and changes to hydrology associated with
reduced and altered freshwater flows and resulting increases in saline
habitat conditions (Factor A); increased water temperatures (Factor A);
reduced food resource availability (Factor E); predation (Factor C);
entrainment from freshwater diversion facilities (Factor E); and
contaminants (Factor E). We consider reduced and altered freshwater
flows resulting from human activities and impacts associated from
current climate change conditions (increased magnitude and duration of
drought and associated increased temperatures) as the main threat
facing the Bay-Delta longfin smelt due to the importance of freshwater
flows to maintaining the life-history functions and species needs of
the DPS. However, because the Bay-Delta longfin smelt is an aquatic
species and the needs of the species are closely tied to freshwater
input into the estuary, the impact of many of the other threats
identified above are influenced by the amount of freshwater inflow into
the system (i.e., reduced freshwater inflows reduce food availability,
increase water temperatures, and increase entrainment potential).
Reduced and Altered Freshwater Flows
The development of dams and water delivery infrastructure built
throughout the Sacramento and San Joaquin River basins for flood
protection and water supply for agriculture and human consumption has
greatly impacted freshwater flows into the San Francisco Bay estuary
(Service 2022, section 3.1.1). The creation of this water storage and
delivery system, where water is stored during the wet season and
conveyed to farms and cities during the dry season, has resulted in one
of the largest human-altered water systems in the world (Nichols et al.
1986, p. 569). Operation of this system has resulted in a broader,
flatter hydrograph with less seasonal variability, thus changing the
timing, magnitude, and duration of freshwater flows into the San
Francisco Bay-Delta (Kimmerer 2004, p. 15; Andrews et al. 2017, p. 72;
Gross et al. 2018, p. 8). It is estimated that the State and Federal
water projects annually reduce an average of about 5 million acre-feet
(MAF) of freshwater into the Delta, while other municipal or private
reservoirs or diverters annually decrement an additional 8 MAF of
potential freshwater into the Delta (Hutton et al. 2017, fig. 4, p. 8).
The cumulative effect of this annual average of about 13 MAF of
freshwater supplies has resulted in a long-term decline in freshwater
inflow into the estuary during the period of February through June
relative to estimates of what flows would have been available absent
water development (Gross et al. 2018, fig. 6, p. 12; Reis et al. 2019,
fig. 3, p. 12). This situation has further increased the frequency of
very low outflow years that, prior to water development, would have
been very rare and associated only with extreme drought (Reis et al.
2019, fig. 3, p. 12).
In addition to the flood control and water storage and delivery
systems, water diversion and export systems are also reducing
freshwater inflow into the system (Kimmerer and Nobriga 2008, p. 2).
From 1956 to the 1990s, water exports increased, rising from
approximately 5 percent of the Delta freshwater inflow to approximately
30 percent of the Delta inflow (Cloern and Jassby 2012, p. 7). By 2012,
an estimated 39 percent of the estuary's unimpaired freshwater flow in
total was either consumed upstream or diverted from the estuary (Cloern
and Jassby 2012, p. 8).
A reduction in freshwater flows into the estuary influences and
impacts the location and extent of the low-salinity zone (spawning and
rearing habitat). Freshwater inflow into the estuary and other co-
linear indicators of wet versus dry conditions during the winter and
spring have been statistically associated with first-year recruitment
of Bay-Delta longfin smelt (Service 2022, section 3.1.1). Prior to
large-scale water exports and reduced freshwater flows, the location of
the low-salinity zone (X2) reached the <=55-km (34-mi) point in the
estuary (monthly averages from February through May) in about half of
all years. More recently the position of the low-salinity zone reaching
at least the 55-km (34-mi) point occurred only very rarely as a result
of wet year conditions (Gross et al. 2018, fig. 6, p. 12 and fig. 7, p.
13) (Service 2022, section 3.1.1). In the case of Bay-Delta longfin
smelt, the amount of low-
[[Page 60964]]
salinity habitat available for optimal growth and rearing conditions
(food and water conditions (salinity, turbidity)), especially for early
life stage fish, is directly linked to freshwater inflow.
Drought Conditions
California's annual weather and rainfall patterns can be extremely
variable and alternate from wet to dry periods from year to year.
Occasionally, several years of dry conditions have occurred over
numerous extended periods (i.e., varying levels of drought) (Department
of Water Resources (DWR) 2020, entire). Drought periods can be
characterized as having less freshwater flow, as well as shorter
duration and lower magnitude of peak flows. The current trend in
drought conditions has recently increased in frequency, duration, and
magnitude (Swain et al. 2018, pp. 427-433). Prior to the 21st century,
dry and critically dry years occurred approximately 33 percent of the
time. However, since the year 2000, the dry and critically dry year
frequency has increased to 43 percent. Based on soil moisture
reconstruction, the period between 2000-2021 was probably the driest
22-year period on record (Williams et al. 2022, p. 1). As the existing
impacts from climate change (i.e., warmer temperatures) increase
evapotranspiration in the watershed, the aforementioned water supply
needs can exacerbate the magnitude of realized dry conditions over and
above these natural patterns in precipitation and reduced delta
freshwater inflow.
Bay-Delta longfin smelt exhibit poor survival and reproduction
during droughts (Thomson et al. 2010, pp. 1438-1446; Mahardja et al.
2021, pp. 9-10). The survival of Bay-Delta longfin smelt through their
early life-stages is lower during dry conditions and higher during wet
conditions, as evidenced by Bay-Delta longfin smelt abundance indices
nearly always declining sharply during dry periods then rebounding when
wet weather returns (Mahardja et al. 2021, pp. 9-10). However, such
recovery does not always occur after each drought cycle, leading to
lower baseline numbers for the DPS (Moyle 2002, p. 237; Sommer et al.
2007, pp. 270-276). In addition, extended dry years compound the
negative impacts to Bay-Delta longfin smelt as the DPS has not shown an
ability to quickly recover and reoccupy upstream spawning habitats
following drought. These drought conditions have exacerbated the impact
of reduced freshwater flows from human activities and have been
attributed to accelerating the establishment of the overbite clam
(Potamocorbula amurensis) (see Reduced Food Resources and Pelagic
Organism Decline (POD), below) by making saline water conditions more
available throughout areas typically associated with more freshwater
(Carlton et al. 1990, pp. 90-91).
Habitat Alteration
Large-scale habitat alteration such as channelization and dredging
of streams and bays, building of levees and canals, and draining of
wetlands has occurred since the 1850s. The impacts of such in-water and
adjacent upland habitat alterations greatly affected and continues to
impact the bathymetry of the estuary by collectively making the estuary
deeper and less hydrodynamically connected to the surrounding landscape
(Andrews et al. 2017, fig. 5, p. 64). The altered waterways create more
space and avenues for the incoming tides to bring more saline water
landward. Specifically, landscape changes since 1850 are estimated to
have resulted in an average landward shift of X2 of over 3 km (2 mi)
(Andrews et al. 2017, p. 68). This change along with reductions in
freshwater input into the estuary (see Reduced and Altered Freshwater
Flows, above) has caused a winter-spring upstream (landward) shift of
X2 on the order of 10-20 km (6-12 mi). Taken together, the landscape
changes discussed above and changes to the estuary's flow regime have
changed how mixing processes function, and thus altered the habitat and
food resource opportunities available for the estuary's biota,
including the Bay-Delta longfin smelt
Water Temperature Alterations
The water temperature within the San Francisco Bay Estuary is also
greatly influenced by freshwater inflow (Vroom et al. 2017, pp. 9918-
9920). The reduction and alteration of freshwater flows into the San
Francisco Bay estuary has limited the area where appropriate water
temperature conditions for the Bay-Delta longfin smelt occur. As
described in the Life History and Biology section of the SSA report
(Service 2022, section 2.4) and summarized above, Bay-Delta longfin
smelt spawning occurs within cool water conditions below 15 [deg]C (59
[deg]F), while larvae and young juveniles show a preference for
temperatures below 12 [deg]C (54 [deg]F) and 20 [deg]C (68 [deg]F),
respectively. The embryonic through early juvenile life stages are when
Bay-Delta longfin smelt are believed to be most vulnerable to warming
temperatures because these early life stages do not possess the ability
to migrate to the cooler waters of central San Francisco Bay and the
coastal ocean. Bay-Delta longfin smelt are also most abundantly
detected within a narrow temperature range of cool water relative to
the range that occurs in the upper estuary. Several studies and reports
have found water temperatures in the Delta (the area containing
favorable freshwater conditions) commonly exceeds 22 [deg]C (72 [deg]F)
during the summer (Vroom et al. 2017, p. 9904; data from California
Data Exchange Center, Central & Northern California Ocean Observing
System, and U.S. Geological Survey (Blodgett et al. 2011, entire)).
Increased freshwater inflow during the appropriate period of time
greatly influences the amount and distribution of favorable spawning
and rearing water temperature conditions (Service 2022, section 3.1.3).
Reduced Food Resources
As discussed above and in the SSA report (Service 2022, section
3.1.2), the Bay-Delta longfin smelt historically limited their diet to
a relatively small number of crustacean meso- and macrozooplankton
taxa. Bay-Delta longfin smelt larvae have diets dominated by a copepod,
Eurytemora affinis, that is common in the low-salinity zone during the
spring (California Department of Fish and Wildlife (CDFW), unpublished
data). The two most common prey taxa for larger longfin smelt are
epibenthic mysids and amphipods (Burdi 2022, pers. comm.; CDFW unpub.
Diet Study Data). The copepod E. affinis was also at one time an
important prey item for a now much-depleted mysid species, Neomysis
mercedis (Knutson and Orsi 1983, p. 478), a prey species of juvenile
and adult Bay-Delta longfin smelt.
Since the 1970s, the Eurytemora affinis population in the estuary
has been in decline, but beginning in the late 1980s, the zooplankton
community for the San Francisco Bay estuary started undergoing about a
decade of rapid change in species composition, trophic structure, and
utility for fish production (Winder and Jassby 2011, pp. 683-685;
Kratina et al. 2014, p. 1070; Brown et al. 2016, p. 8). This decline
coincided with the rapid invasion of the estuary by the nonnative
overbite clam (Carlton et al. 1990, pp. 81 and 85, fig. 3) and with an
extended drought in the Central Valley in the period 1987-1994
(Rosenfield and Baxter 2007, p. 1589).
The overbite clam is a filter feeder that is thought to have
diverted food resources from the primary food sources of, or fed
directly on, the nauplii (first larval stage) of common calanoid
copepods, and resulted in their decline. These native copepods are one
of the
[[Page 60965]]
main sources of prey of larval Bay-Delta longfin smelt (Carlton et al.
1990, pp. 90-91; Kimmerer et al. 1994, p. 87; Feyrer et al. 2003, pp.
284-286; Rosenfield and Baxter 2007, p. 1589). The invasion of the
overbite clam has resulted in an over tenfold decrease in abundance of
native copepods, which now account for less than 4 percent of total
zooplankton biomass within the estuary after 1994 (Winder and Jassby
2011, p. 684). In addition to lower abundance, the average individual
sizes of mysids in the estuary have decreased over time, with a species
composition shift towards Hyperacanthomysis longirostris, an invasive
species that reaches maturity at a smaller mass than Neomysis species
(Hennessy 2011, entire). Although Bay-Delta longfin smelt consume these
nonnative species, they are not preferred (see below) and the change in
food resources most likely results in an increased effort for the DPS
to meet its food resource needs.
To further exacerbate the impacts of the change in food resources,
the decline of the Bay-Delta longfin smelt's historical prey base has
not been accompanied by a large change in prey use by the DPS (Barros
et al. 2019, p. 15; Feyrer et al. 2003, p. 285). This finding suggests
that Bay-Delta longfin smelt had formed strong predator-prey
interactions with their primary prey, a hypothesis supported by
empirical data (MacNally et al. 2010, p. 1426). Because the DPS
continues to exhibit very little variation in prey use despite the
reduction in natural prey availability, they are considered more
susceptible to food web changes than some other fishes (Feyrer et al.
2003, p. 281). The decline in food resources is likely affecting
juvenile and adult longfin smelt growth and fitness as well as
increasing the effort needed to meet food resource demands (Kimmerer
and Orsi 1996, pp. 418-419; Feyrer et al. 2003, p. 281). The result of
the introduction of overbite clam and reduced freshwater flows has
limited abundances and availability of the Bay-Delta longfin smelt's
primary food sources, especially for larval and rearing individuals
that are restricted to the low-salinity zone during their development.
Predation
Little information is available on the exact predators of the Bay-
Delta longfin smelt; however, Bay-Delta longfin smelt are relatively
small fish, even as adults, and are thus most likely food for many
fish-eating (piscivorous) predators, such as birds, jelly fish, and
other fish (CDFW 2009a, p. 27). The number of piscivorous fish in the
San Francisco Bay estuary is considerable (Grossman 2016, pp. 5, 12).
However, studies on the diets of predatory fish in the estuary provide
limited insight into predation of the Bay-Delta longfin smelt. These
studies were based on visually identifying the stomach contents of
numerous species of predatory fish in the estuary. In most cases, these
studies did not find Bay-Delta longfin smelt (Stevens 1966, pp. 94-96;
Thomas 1967, pp. 51, 57; Nobriga and Feyrer 2007, unpaginated, Results/
Discussion section; CDFW 2009a, pp. 27-28; Grossman 2016, pp. 9-16). In
one study in Suisun Marsh and the Sacramento-San Joaquin Delta that
used DNA analysis of stomach contents, Bay-Delta longfin smelt were
identified as prey of Sacramento pikeminnow (Ptychocheilus grandis),
striped bass (Morone saxatilis), and largemouth bass (Micropterus
salmoides), but only rarely (Brandl et al. 2021, tables 2 and 4).
However, given the Bay-Delta longfin smelt's recent low abundance (see
SSA report, section 3.2. Current DPS Survey Indices (Service 2022, pp.
41-46)) and limitations typical of field-based food-habit studies, it
is expected that the Bay-Delta longfin smelt would rarely be identified
in the diet of piscivorous fishes, since predatory fish feed
predominantly on the fish prey that is most available (Nobriga and
Feyrer 2007, unpaginated, Results/Discussion sections; CDFW 2009a, p.
27; Grossman 2016, p. 15).
Because information on direct predation is lacking, we reviewed
general information about predator-prey relationships in fish food webs
that are broadly applicable to situations and conditions faced by the
Bay-Delta longfin smelt. The early life stages of fish are often
subject to high rates of predation that play important roles in
modulating abundance and amplifying the consequences of food limitation
(Ahrens et al. 2012, fig. 2, p. 46, and throughout; Pangle et al. 2012,
pp. 5-6). Chronic food limitation (such as those described for the Bay-
Delta longfin smelt described above) and predation risk are often
tightly linked in fish food webs (Ahrens et al. 2012, pp. 47-48). One
way prey organisms reduce their risk to predation is to limit their
foraging times, which are often relatively risky because small fishes
have to behave in ways that increase their exposure or attractiveness
to predators when they are actively foraging (e.g., leaving sheltered
habitats, moving around more actively) (Ahrens et al. 2012, fig. 1, p.
43). Thus, when food densities decline, prey fishes have two choices.
They can either eat less and grow more slowly or they can increase
foraging times to compensate for the lower prey densities, which may
result in an increased predation risk. Other factors such as habitat or
ecosystem conditions, such as turbidity and food availability, also
play an important part in this relationship.
Although predation and its effects do impact the Bay-Delta longfin
smelt, we do not consider the impacts to be a primary driver, but we
still include this consideration as part of the cumulative impact from
all threats for the DPS, especially during poor habitat conditions when
food is lacking.
Entrainment
Freshwater diversion occurs throughout the estuary through pumping
for agricultural, waterfowl, or municipal purposes and in some cases
may lead to entrainment of Bay-Delta longfin smelt. Entrainment occurs
when the suction caused by pumping creates an opportunity for fish to
follow or be captured by the flow of water and become trapped and
transported by the hydrodynamic footprint of those diversions. This
entrainment often results in fish, especially early-life-stage fish,
being killed or removed from the estuary. Bay-Delta longfin smelt can
be entrained in water exported by the major pumping facilities in the
South Delta (see Water Project Exports, below) when adults and
commingling age-1 individuals move upstream into the freshwater
portions of the Delta (CDFW 2020a, fig. 13, p. 53). Bay-Delta longfin
smelt larvae and small juveniles that are either rearing or being
tidally dispersed landward of X2 can also be entrained (CDFW 2020a,
fig. 13, p. 53). During periods of high freshwater flow into the
estuary, Bay-Delta longfin smelt (adults, juveniles, and larvae) are
much less likely to be entrained by the major pumping facilities in the
South Delta because the low-salinity zone (X2) is further downstream
(or seaward) of the Delta. Individuals are more likely to be cued to
spawn in tributaries of the San Francisco, San Pablo, and Suisun Bays
rather than in the Delta since these tributaries would also be flowing
high. However, changes to the estuary's bathymetry (see Habitat
Alteration, above) have caused the tidal flows to reach further into
the Old and Middle Rivers (Andrews et al. 2017, p. 66) which, as
discussed below, may further impact Bay-Delta longfin smelt (see Water
Project Exports, below). Below we describe the types of freshwater
diversions and exports and their impacts on Bay-Delta longfin smelt.
Agricultural Diversions: Freshwater is diverted at numerous sites
throughout the Delta for agricultural purposes,
[[Page 60966]]
particularly during the summer months (Siegfried et al. 2014, figs. 10-
11, p. 11). Based on the life history of the DPS during this timeframe,
the majority of Bay-Delta longfin smelt are seeking cooler water during
the late spring and summer and are more seaward of the Delta and areas
associated with agricultural diversions. Given the temporal mismatch
between seasonal peaks in agricultural water diversions and limited use
of the Delta waterways by Bay-Delta longfin smelt during this
timeframe, we do not consider seasonal diversion of water for
agricultural purposes and the potential for entrainment to be a high-
level threat for the DPS but this activity still contributes
cumulatively with other threats facing the population.
Wetland Diversions: In Suisun Marsh, the Roaring River and Morrow
Island Distribution Systems (RRDS and MIDS) are California Department
of Water Resources (DWR) facilities that divert water from Montezuma
and Goodyear sloughs in Solano County, respectively. The water is
distributed to waterfowl management wetlands in Suisun Marsh and
eventually returned to marsh channels leading to Suisun Bay (minus what
evaporates and is retained in wetland areas). Both diversions have been
observed to entrain Bay-Delta longfin smelt (Enos et al. 2007, p. 16;
CDFW 2009a, pp. 40-41). The RRDS has fish screens that were installed
to reduce entrainment of fish in the vicinity of the diversion, which
was recognized as a source of fish mortality (Pickard et al. 1982, pp.
4-10). The MIDS pumping facility is not screened. However, based on the
results of monitoring, MIDS is considered not to have a great influence
on entrainment of Bay-Delta longfin smelt (Enos et al. 2007, pp. 16-18;
CDFW 2020a, p. 63).
Water Project Exports: The State of California through the DWR and
the Federal Bureau of Reclamation operate freshwater diversion
facilities and infrastructure associated with the State Water Project
(SWP) and Central Valley Project (CVP) respectively. These facilities
export freshwater from the Delta. The DWR also operates the Barker
Slough Pumping Plant, which diverts water from Barker Slough into the
North Bay Aqueduct (NBA) for delivery in Napa and Solano Counties. The
Barker Slough diversion has positive barrier fish screens that were
installed to reduce entrainment of fish in the vicinity of the
diversion, which was recognized as a source of mortality for federally
listed species such as the delta smelt (Hypomesus transpacificus),
chinook salmon (Oncorhynchus tshawytscha) (Sacramento River winter-run,
California coastal, Central Valley spring-run salmon), and steelhead
salmon (Oncorhynchus mykiss)) (Service 2008, pp. 111-232). In dry
seasons and at higher pumping rates, modeling data suggest the
facilities could exhibit some level of entrainment vulnerability,
despite the fish screens in place (Service 2008, p. 231). The SWP and
CVP each include pumping plants in the south Delta. These pumping
plants are used to export freshwater to users for municipal and
agricultural purposes via the California Aqueduct to the Central Valley
and Southern California. The operation of these facilities can exert a
strong influence on regional hydrodynamics that has resulted in the
entrainment of Bay-Delta longfin smelt, sometimes from considerable
distances (Kimmerer 2008, p. 2, fig. 1, p. 3; Kimmerer and Nobriga
2008, fig. 7, p. 12; Hutton et al. 2019, fig. 7, p. 11).
Several methods have been implemented to limit and offset the
entrainment impacts at these facilities, including construction of
forebays (areas used to collect fish before they enter the pumps), fish
screens, gate systems (used to divert fish away from pumps), and
salvage operations (active collection and transport of fish back into
the estuary). In most years, Bay-Delta longfin smelt have been
collected (``salvaged'') in the fish facilities that are in front of
each pumping plant and from screens on the pump intakes. The salvage of
fish is an indicator that individuals are being entrained by pumping of
water at these facilities and either being killed or removed from the
estuary. The peak of salvage of age-1 and older Bay-Delta longfin smelt
typically occurs in January (Grimaldo et al. 2009, fig. 5, p. 1262).
These adult and age-1 fish likely represented individuals searching for
spawning habitats, and immature individuals commingling with the
adults. The peak of salvage of age-0 fish (fish younger than 1 year
old) typically occurs in April or May as larval fish reach sizes at
which they could be retained on the fish screens of the CVP and SWP
fish collection facilities. However, in all likelihood some larvae
begin to be entrained once they start hatching in December or January,
but remain undetected until about March, with salvage efficiency
increasing in April-May as the fish grow larger. Despite these salvage
operations helping conserve Bay-Delta longfin smelt, the salvage
operations themselves are not free from impacts on the DPS as
collection, transportation, and release of salvaged fish often causes
additional mortality of individuals (CDFW 2009b, pp. 4-20, table 2;
CDFW 2020a, pp. 23-24, table 1).
It is possible that past entrainment and loss of Bay-Delta longfin
smelt may have reached levels of concern (CDFW 2020a, fig. 10, p. 47).
However, since 2009, the entrainment of longfin smelt has not been
substantial (Service 2022, fig. 3.4), perhaps partly due to monitoring
and management of flows in the Old and Middle Rivers (OMR) between the
Sacramento/San Joaquin River confluence and the export facilities. When
net OMR flow is positive, San Joaquin River water is generally moving
seaward through the Delta and away from the pumping facilities. The
more net negative OMR is flowing, the more the water in the Delta is
moving back upstream toward the pumping plants and the faster that
water is moving south, thereby increasing entrainment potential. The
additional negative flow causes Sacramento River water entering the
northwest portion of the Delta to be diverted southward toward the
pumping facilities rather than seaward, which allows saltier tidal
flows to move further toward the Delta and reduces spawning habitat for
the Bay-Delta longfin smelt. In order to address and minimize effects
to federally listed fish species (delta smelt, chinook salmon
(Sacramento River winter-run, California coastal, Central Valley
spring-run salmon), and steelhead salmon), restrictions to pumping and
other water operations management strategies have been implemented by
the DWR and Reclamation to limit negative OMR flows and associated
entrainment through the section 7 process of the Act (Service 2008,
entire; National Oceanic and Atmospheric Administration, National
Marine Fisheries Service [NMFS] 2009, entire; Service 2019, entire;
NMFS 2019, entire). In addition, the DWR has implemented similar
measures for State-listed species (including longfin smelt) (CDFW 2009c
Incidental Take Permit (ITP), entire; CDFW 2020b, ITP, entire).
The results of two different analytical approaches to the Smelt
Larval Survey (SLS) data suggest that entrainment of fish has not
exceeded 3 percent since 2009 (Kimmerer 2022, pers. comm.). One of the
two analyses coupled particle tracking modeling with the SLS data set
and found an upper 95 percent credible interval of proportional
entrainment was 2.9 percent in the critically dry winter of 2013 and
nearly zero in the wet winter of 2017. A second analysis (similar in
approach to Kimmerer 2008, entire) analyzed all of the SLS data in the
period 2009-2020. Similarly, this approach also found
[[Page 60967]]
proportional entrainment was unlikely to have exceeded 3 percent (range
= 0.5 to 2.9 percent) (Kimmerer 2022, pers. comm., unpublished data).
We interpret these findings, as well as previously published
information (CDFW 2020a, entire), to indicate that the OMR management
strategies in place since 2009 have been an effective conservation
strategy for limiting the impact of entrainment and its consequences
for the Bay-Delta longfin smelt. As a result, the best information
currently available indicates that management actions for operating
water diversion facilities are assisting in limiting entrainment
impacts for the Bay-Delta longfin smelt.
Contaminants
The San Francisco Bay estuary has been identified as an impaired
water body due to it containing numerous and persistent contaminant
compounds (California State Water Resources Control Board 2018,
appendix A). The list of contaminant compounds identified within the
estuary includes elemental contaminants or `metals' (e.g., mercury and
selenium), toxic organic compounds (dioxins, furans, polychlorinated
biphenyls), and pesticides (chlordane dieldrin, DDT). Additional
emerging contaminants of concern include flame retardants, nutrients,
naturally occurring toxins, microplastics, and pharmaceuticals and
personal care products (i.e., plastic microbeads, insect repellant,
sunscreen, cosmetics, etc.) (Klosterhaus et al. 2013, pp. 97-98, table
1; Sutton et al. 2017, entire). Ongoing analysis of water in the Delta
suggests that on average 10 new synthetic organic pesticide chemicals
are detected every year (California Department of Pesticide Regulation
2020, dataset). Water sampling in one study of the Delta indicated the
presence of more than 50 chemical compounds from a single 1-liter (L)
(34-ounce (oz)) water sample (Moschet et al. 2017, pp. 1557-1560).
The sources of contaminants include discharge from municipal
wastewater treatment plants, agricultural outfalls, stormwater runoff,
anti-fouling paints on boat and ship hulls, and direct human
application of pest and aquatic plant control compounds (Service 2022,
section 3.1.6). Legacy contaminants in the Bay-Delta (those from
historical loading, such as organochlorine chemicals (e.g., DDT) from
past agricultural use and mercury from past gold mining activity), have
been shown to persist in the environment and continue to impact
ecosystems and can bioconcentrate through the food web, posing
additional health risks (Connor et al. 2006, pp. 87-88; Marvin-
DiPasquale and Cox 2007, p. 2). Regulation has reduced the use of some
contaminants, only to be replaced by other more potent alternative
water-soluble chemicals such as neonicotinoids, which have additional
impact on nontarget species such as aquatic invertebrates and fish
(Buzby et al. 2020, pp. 15-21).
Field-based toxicity is difficult to determine, as impacted fish
are not recovered in order to be examined (i.e., fish either die from
direct exposure and resulting disease, or are eaten). Risk of exposure
and effect, as determined by comparison to other species (e.g., delta
smelt and the introduced inland silverside (Menidia beryllina)),
potentially include direct effects on development, growth, and
reproduction; impacts resulting from impairments to bioenergetic
demands; and impaired locomotion, reducing feeding success, which can
lead to increased susceptibility to predation, disease, and entrainment
(Connon et al. 2009, p. 12; Connon et al. 2011, p. 299; Brander et al.
2012, p. 2854; Hasenbein et al. 2014, p. 696; Jeffries et al. 2015a, p.
17407; Jeffries et al. 2015b, p. 55; Brander et al. 2016, pp. 247-260;
Cole et al. 2016, p. 219; DeCourten and Brander 2017, p. 2).
Pelagic Organism Decline (POD)
Between the years 2002 through 2004, abundance indices for multiple
fish species within the San Francisco Bay estuary declined abruptly in
what is known as the Pelagic Organism Decline, or POD. Specifically,
the POD referred to a drop in survey catches of four fish species (Bay-
Delta longfin smelt, delta smelt, striped bass (Morone saxatilis), and
threadfin shad (Dorosoma petenense)) (Sommer et al. 2007, p. 273). The
POD event is generally recognized as a population step decline (where
populations decline to lower abundance level and not rebound to
previous levels) for numerous fish species in the estuary. The
coincident declines of multiple species suggested a possible common
cause, but a single mechanism for decline that applied to all four fish
has not been identified (MacNally et al. 2010, p. 1426; Thomson et al.
2010, pp. 1442-1443). As a result, researchers have focused on multiple
causes, from habitat changes, reductions in freshwater inflow, water
diversions, food resource changes, competition, predation, and
contaminants as contributing to the POD (Sommer et al. 2007, pp. 271-
276; MacNally et al. 2010, p. 1418; Fong et al. 2016, pp. 20-21). As
outlined above, all of these factors have been identified as threats
impacting the Bay-Delta longfin smelt to varying degrees. Although the
POD event is not a threat in itself, but is instead most likely a
result of multiple threats, the subsequently smaller populations are
more susceptible to poor habitat conditions and have a reduced
capability of rebounding from lower abundance years.
Bay-Delta Longfin Smelt Current Condition
Current Abundance
Several long-term survey efforts have been established for
monitoring San Francisco Bay estuary fish populations including the
Bay-Delta longfin smelt. These established survey efforts include the
Fall Midwater Trawl (FMWT), the 20-mm Survey, and the San Francisco Bay
Study (Bay Study). The 20-mm Survey has been conducted since 1995, and
although it does not produce an abundance index for Bay-Delta longfin
smelt, we adapted the results of the survey by using the methods in the
study for the delta smelt abundance index for the Bay-Delta longfin
smelt. Our methods and information on how we adapted the study
information is outlined in appendix B of the SSA report (Service 2022,
appendix B). The longest of these survey efforts is the FMWT, which was
initiated in 1967 and has surveyed pelagic waters from the Delta into
San Pablo Bay monthly from September through December each year. The
FMWT captures mostly juvenile and adult fish 50-150 mm (2-6 in) in
length and has been used to monitor the abundance of sampled fish
species since the late 1970s (Stevens and Miller 1983, pp. 431-432). In
the case of Bay-Delta longfin smelt, the FMWT samples adults and
juveniles, most likely those returning from more marine environments to
freshwater areas associated with spawning. Figure 3 identifies FMWT
abundance information for Bay-Delta longfin smelt since its inception
in 1967 with emphasis on the years 2000 to 2020. Similar abundance
estimates are reflected in the 20-mm Survey, Bay Study, and other
modeling efforts (Service 2022, section 3.2.1).
[[Page 60968]]
[GRAPHIC] [TIFF OMITTED] TP07OC22.002
Collectively, these survey efforts encompass abundance estimates of
all life stages of the Bay-Delta longfin smelt in the estuary. The data
from these efforts indicate a recent and significant decline for the
Bay-Delta longfin smelt throughout the estuary and across all life
stages resulting in the conclusion that the current Bay-Delta longfin
smelt population size is considered to be small (Service 2022, section
3.2, appendices A and B).
Population Trends
All the best available field surveys for documenting long-term
abundance trends indicate Bay-Delta longfin smelt numbers have
substantially declined over time, with current relative abundance
reflecting small fractions of the species' historical relative
abundance and representing a decline of three to four orders of
magnitude over the course of available historical abundance records.
Even considering the small periodic increases in numbers in occasional
years in the most recent survey results (past 20 years), the general
trend over time has been lower highs and lower lows in abundance for
the DPS. This finding supports the conclusion that abundance of all
life stages has declined substantially over the course of several
decades and that the overall decline has continued in recent years
(Service 2022, section 3.2). A summary of annual population growth
rates derived from the monitoring data showed that, on average,
abundance has declined from year to year, although some years with
large growth rates contributed to variability (Service 2022, section
3.2.2).
Effects of Threats Impacting the Bay-Delta Longfin Smelt
Reduced and altered freshwater flows into the estuary greatly
impact the availability, distribution, and amount of Bay-Delta longfin
smelt spawning and rearing habitat. Freshwater input into the estuary
provides for proper low-salinity and cooler water conditions for Bay-
Delta longfin smelt to spawn and rear young and provides abundant food
resources for the DPS. Reductions in availability of such habitat
conditions reduces the number of young available to mature to breeding
age the following year. Reduced freshwater flows also require the DPS
to move farther inland to find appropriate low-salinity conditions for
spawning and rearing. This movement farther inland makes the DPS's
larvae and young more vulnerable to entrainment as a result of water
diversion from water export facilities. These larvae and young are
often not captured and returned to the estuary as a result of salvage
measures due to their smaller size.
The amount of freshwater input into the estuary is dependent on
natural wet/dry precipitation patterns. These patterns have been
influenced by the effects of current climate change conditions, which
have resulted in more frequent, prolonged, and intense drought
conditions (reduced flows) and increased water temperatures (poor
habitat conditions). Freshwater flows into the estuary have also been
greatly influenced by human-caused alteration of rivers and streams
leading into the estuary as well as diversion and export of freshwater
from the estuary. These human-caused impacts of water management have
exacerbated the impacts of environmental variability of natural wet/dry
precipitation patterns.
In addition to altered habitat conditions for the Bay-Delta longfin
smelt, the available food resources for the DPS have also been severely
impacted. A rapid change to the zooplankton community in the estuary
beginning in the late 1980s along with the introduction of the
nonnative species such as the overbite clam and others has greatly
reduced the natural prey base for the DPS and replaced it with a
smaller nonnative mysid. Because the DPS continues to exhibit very
little variation in prey use despite the reduction in natural prey
availability, they are considered more susceptible to food web changes
than some other fishes. The decline in food resources is likely
affecting juvenile and adult longfin smelt growth and fitness as well
as increasing the effort needed to meet food resource demands.
After the review of the threats of predation, entrainment, and
contaminants, we have determined that they are not primary driving
factors currently influencing the Bay-Delta longfin smelt. However,
these threats are likely still contributing cumulatively to the overall
impacts acting on the DPS.
We note that, by using the SSA framework to guide our analysis of
the scientific information documented in
[[Page 60969]]
the SSA report, we have not only analyzed individual effects on the
DPS, but we have also analyzed their potential cumulative effects. We
incorporate the cumulative effects into our SSA analysis when we
characterize the current and future condition of the DPS. To assess the
current and future condition of the DPS, we undertake an iterative
analysis that encompasses and incorporates the threats individually and
then accumulates and evaluates the effects of all the factors that may
be influencing the DPS, including threats and conservation efforts.
Because the SSA framework considers not just the presence of the
factors, but to what degree they collectively influence risk to the
entire DPS, our assessment integrates the cumulative effects of the
factors and replaces a standalone cumulative effects analysis.
Resiliency, Redundancy, and Representation for the Bay-Delta Longfin
Smelt
In the SSA report for the Bay-Delta longfin smelt (Service 2022,
chapter 3), we evaluated the Bay-Delta longfin smelt's resiliency,
redundancy, and representation under our SSA framework (Service 2016,
entire).
Resiliency describes the ability of a species to withstand
stochastic disturbance. Because the Bay-Delta longfin smelt is a
single, intermixed population, we did not identify multiple resiliency
units, but looked at the population as a whole. As discussed above, the
Bay-Delta longfin smelt is subject to multiple interacting threats,
including saltwater intrusion and reduced freshwater flows, that are
altering and degrading habitat conditions. The resulting impact of
these threats limits the extent, duration, and availability of
appropriate habitat conditions needed for spawning, rearing, and
ultimate recruitment of individuals into the population. These threats
include anthropogenic actions (such as freshwater management,
freshwater diversion, and physical alterations to the bathymetry of the
estuary) or poor or altered environmental conditions (such as increased
frequency and magnitude of drought resulting from current climate
change conditions). Disruptions to the estuary's food web associated
with reductions in freshwater flow or introductions of nonnative
species are also limiting resiliency for the DPS.
Redundancy is the ability of a species to withstand catastrophic
events. The Bay-Delta longfin smelt is a single intermixed population
and occurs in areas within the San Francisco Bay estuary as dictated by
the extremely modified and altered habitat and resource conditions. The
estuary is also subject to extreme environmental variability as a
result of climate change conditions resulting in increased temperatures
and extreme drought. As a result of these changes, the ability of the
system and organisms within the estuary to withstand catastrophic
events and rebound during periods of more favorable conditions is
greatly reduced. Large-scale estuary-wide ecosystem population
collapses of fish and native zooplankton have occurred in the estuary.
Although no single cause for the collapses has been identified, both
native and nonnative fish populations have not recovered. The result
has been step-declines of the Bay-Delta longfin smelt population size
since the mid-1980s.
Representation describes the ability of a species to adapt to
changing environmental conditions over time. This definition includes
the ability of a species to adapt to both near-term and long-term
changes in its physical and biological environments. The Bay-Delta
longfin smelt population occurs in the San Francisco Bay estuary and is
a single, genetically indistinguishable population. The Bay-Delta
longfin smelt represents the southern extent of the species as a whole
and most likely is a source for populations along the coast north of
San Francisco Bay. Due to ocean currents and the species' poor swimming
capability, populations north of the San Francisco Bay have limited
ability to reestablish a population in the San Francisco Bay-Delta once
they have been extirpated from the San Francisco Bay-Delta. The DPS's
ability to adapt behaviorally to environmental changes (to have
adaptive capacity) is also limited. This limitation is exemplified by
the DPS's behavioral tendency of not adapting to food resource changes.
As discussed, food resources for the DPS have changed significantly yet
the DPS's behavior has not shifted to adapt to those changes.
In our evaluation of the current condition of the Bay-Delta longfin
smelt, we evaluated several population viability analyses (PVAs) that
quantitatively derive probabilities of extinction over time based on
the DPS's historical and current abundance estimates (Service 2022, pp.
107-120; appendix B). The PVAs used information from the existing suite
of surveys, including the FMWT, the 20-mm Survey, and the Bay Study, as
well as others (Service 2022, figure 3.11). The PVAs modeled extinction
probability based on a continuation of existing threats currently
facing the DPS under varying levels of population recruitment. The
results of the PVAs identified that the probability of quasi-extinction
for the Bay-Delta longfin smelt exceeds 20 percent over the next 5
years and reaches 50-60 percent by 2040 (Service 2022, pp. 107-120).
Applying the same assumptions over a longer time horizon (i.e., 2050-
2065), the suite of surveys used in the PVAs predicts that the
probability of extinction for the Bay-Delta DPS under current
conditions is roughly 50-80 percent (Service 2022, pp. 107-120).
As a result of our review of the best scientific and commercial
data available on the Bay-Delta longfin smelt, we have determined that
the DPS's resiliency is low. Numerous decades of declining abundance
indices for the Bay-Delta longfin smelt document the inability of the
DPS to rebound during more favorable environmental conditions and
respond to the threats it is facing in the contemporary San Francisco
Bay estuary. The Bay-Delta longfin smelt also has extremely limited
redundancy because it effectively represents a single, small population
inhabiting the San Francisco Bay-Delta and nearshore ocean environment,
and because it continues to be impacted by large-scale stochastic
events and is subject to catastrophic events. We have determined that
the representation of the Bay-Delta longfin smelt is limited as well,
reflecting that same declining abundance trend and no discernible and
quantifiable compensatory adaptation to current ecological conditions.
Based on our evaluation of the current resiliency, redundancy, and
representation for the Bay-Delta longfin smelt, we conclude the current
ability of the DPS to maintain populations in the wild is low.
Future Condition
As part of the SSA, we also developed future condition scenarios to
capture the range of uncertainties regarding future threats and the
projected responses by the Bay-Delta longfin smelt. To assess the
future condition of the Bay-Delta longfin smelt, we used published
information related to the varying environmental conditions of the San
Francisco Estuary, including future climate change information and
projected increases in water demand, and how these changes may impact
how well the estuary can support the Bay-Delta longfin smelt into the
foreseeable future. In our analyses, we considered two plausible future
scenarios based on representative concentration pathways (RCP) 4.5 and
8.5 as the bookends for our analysis. The scenarios assessed climate
change information (temperature increases, changes precipitation
patterns, sea-level rise)
[[Page 60970]]
through 2100, as published information was available. The information
identified that declines in Bay-Delta longfin smelt population
abundance will continue into the foreseeable future under both the RCP
4.5 and 8.5 scenarios. Because we determined that the current condition
of the Bay-Delta longfin smelt was consistent with an endangered
species (see Determination of the Bay-Delta Longfin Smelt's Status,
below), we are not presenting the results of the future scenarios in
this proposed rule. Please refer to the SSA report ((Service 2022,
Chapter 4) for the full analysis of future scenarios.
Conservation Efforts and Regulatory Mechanisms
Numerous efforts have been initiated regarding conservation and
regulation of the San Francisco Bay estuary and its resources,
including managing water flows into and export from the estuary,
improving water quality, conducting habitat restoration, and
implementing measures or regulations to protect native fish. This
effort includes establishment of multiagency collaborations such as the
Interagency Ecological Program (IEP), which focuses on coordinating and
prioritizing science needs and research to meet responsibilities under
State and Federal regulatory requirements (IEP 2014, entire). The State
of California listed the longfin smelt in the San Francisco Bay estuary
and along the California Coast as a threatened species under the
California Endangered Species Act in 2009 (CDFW 2009a, entire;
California Natural Diversity Database 2022, entire) and has issued
restrictions and requirements for the export of water for the State
Water Project (see Entrainment, Water Project Exports, above). Several
other fish species (delta smelt, several salmonid species) are listed
under both the Act and the California Endangered Species Act, and the
Service and NMFS have also issued biological opinions regarding the
effects to these species and their habitats for delivery and export of
water from the estuary (see Entrainment, Water Project Exports, above).
The State Water Board is responsible for issuing water quality
standards and monitors contaminants within the estuary (see
Contaminants, above). However, despite efforts such as those identified
above, the current condition of the estuary and continued threats
facing the estuary and Bay-Delta longfin smelt, such as reduced
freshwater inflow, severe declines in population size, and disruptions
to the DPS's food resources have not been ameliorated.
Determination of the Bay-Delta Longfin Smelt's Status
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species meets the definition of an endangered species or a
threatened species. The Act defines an ``endangered species'' as a
species in danger of extinction throughout all or a significant portion
of its range and a ``threatened species'' as a species likely to become
an endangered species within the foreseeable future throughout all or a
significant portion of its range. The Act requires that we determine
whether a species meets the definition of an endangered species or a
threatened species because 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.
Status Throughout All of Its Range
The current Bay-Delta longfin smelt abundance, density, and
distribution throughout the San Francisco Bay estuary have
substantially declined. Currently, the DPS exists in very low abundance
despite periods when appropriate habitat conditions, which typically
would allow for population rebounds, are available. Our analysis
revealed that several threats are causing or contributing to this
decline and currently pose a meaningful risk to the viability of the
DPS. These threats have put the Bay-Delta longfin smelt largely into a
state of chronic population decline due to habitat loss (reduction in
freshwater flows into the estuary), which is exacerbated by limited
food resources and the impacts associated with climate change, thereby
limiting its resiliency and ability to withstand catastrophic events
(reduced redundancy). This decline in numbers of the Bay-Delta longfin
smelt is also a reflection of the DPS's ability to adapt to the
ecosystem changes. As a result of the DPS's poor performance in
adapting to the suite of stressors acting upon it, we consider the Bay-
Delta longfin smelt's adaptive capacity and, therefore, its current
representation to be low. The Bay-Delta longfin smelt's continued
reduced population size makes the DPS vulnerable to varying habitat
conditions (reduced freshwater flows) from year to year due to both
anthropogenic and environmental conditions that are being influenced by
the effects of climate change. Historically, with a larger population
size, the DPS was more resilient to such stochastic and catastrophic
events due to its ability to rebound in abundance when habitat
conditions and resources would allow. The habitat changes, limitations
to food resources, and resulting small population size now limit the
DPS's ability to maintain its current population.
After evaluating threats to the DPS and assessing the cumulative
effect of the threats under the section 4(a)(1) factors, we find that
the threats facing the San Francisco Bay-Delta DPS of the longfin smelt
are current and ongoing and include habitat degradation and reduction
from reduction of freshwater outflow from the Delta into the estuary
(Factor A), increased intrusion of saltwater into spawning habitat
areas (Factor A), alteration of food resources and availability (Factor
E), nonnative species competition and food resource effects (Factor E),
and the effects associated with climate change such as increased
temperatures and frequency, magnitude, and duration of drought (Factor
E). Because these threats are ongoing and currently impacting the DPS,
and have already been shown to have caused a significant decline in the
DPS's current resiliency, redundancy, and representation, the DPS meets
the Act's definition of endangered status.
Thus, after assessing the best available information, we determine
that the San Francisco Bay-Delta DPS of the longfin smelt is in danger
of extinction throughout all of its range.
Status Throughout a Significant Portion of Its Range
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
in the foreseeable future throughout all or a significant portion of
its range. We have determined that the San Francisco Bay-Delta longfin
smelt DPS is in danger of extinction throughout all of its range and
accordingly did not undertake an analysis of any significant portion of
the DPS's range. Because the DPS warrants listing as endangered
throughout all of its range, our determination does not conflict with
the decision in Center for Biological Diversity v. Everson, 435 F.
Supp. 3d 69 (D.D.C. 2020), because that decision related to significant
portion of the range analyses for species that warrant listing as
threatened, not endangered, throughout all of their range.
[[Page 60971]]
Determination of Status
Our review of the best available scientific and commercial
information indicates that the San Francisco Bay-Delta longfin smelt
DPS meets the definition of an endangered species. Therefore, we
propose to list the San Francisco Bay-Delta longfin smelt DPS as
endangered in accordance with sections 3(6) and 4(a)(1) of the Act.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition as a listed
species, planning and implementation of recovery actions, requirements
for Federal protection, and prohibitions against certain practices.
Recognition through listing results in public awareness, and
conservation by Federal, State, Tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and other countries and calls for recovery actions to be carried
out for listed species. The protection required by Federal agencies,
including the Service, and the prohibitions against certain activities
are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Section 4(f) of the Act calls for the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The goal of this process is to restore listed
species to a point where they are secure, self-sustaining, and
functioning components of their ecosystems.
The recovery planning process begins with development of a recovery
outline made available to the public soon after a final listing
determination. The recovery outline guides the immediate implementation
of urgent recovery actions while a recovery plan is being developed.
Recovery teams (composed of species experts, Federal and State
agencies, nongovernmental organizations, and stakeholders) may be
established to develop and implement recovery plans. The recovery
planning process involves the identification of actions that are
necessary to halt and reverse the species' decline by addressing the
threats to its survival and recovery. The recovery plan identifies
recovery criteria for review of when a species may be ready for
reclassification from endangered to threatened (``downlisting'') or
removal from protected status (``delisting''), and methods for
monitoring recovery progress. Recovery plans also establish a framework
for agencies to coordinate their recovery efforts and provide estimates
of the cost of implementing recovery tasks. Revisions of the plan may
be done to address continuing or new threats to the species, as new
substantive information becomes available. The recovery outline, draft
recovery plan, final recovery plan, and any revisions will be available
on our website as they are completed (<a href="https://www.fws.gov/endangered">https://www.fws.gov/endangered</a>),
or from our San Francisco Bay-Delta Fish and Wildlife Office (see FOR
FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
If this DPS is listed, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost-share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. In addition,
pursuant to section 6 of the Act, the State of California would be
eligible for Federal funds to implement management actions that promote
the protection or recovery of the Bay-Delta longfin smelt. Information
on our grant programs that are available to aid species recovery can be
found at: <a href="https://www.fws.gov/service/financial-assistance">https://www.fws.gov/service/financial-assistance</a>.
Although the Bay-Delta longfin smelt is only proposed for listing
under the Act at this time, please let us know if you are interested in
participating in recovery efforts for this species. Additionally, we
invite you to submit any new information on this species whenever it
becomes available and any information you may have for recovery
planning purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as an
endangered or threatened species and with respect to its critical
habitat, if any is designated. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) of the Act requires Federal agencies to
confer with the Service on any action that is likely to jeopardize the
continued existence of a species proposed for listing or result in
destruction or adverse modification of proposed critical habitat. If a
species is listed subsequently, section 7(a)(2) of the Act requires
Federal agencies to ensure that activities they authorize, fund, or
carry out are not likely to jeopardize the continued existence of the
species or destroy or adversely modify its critical habitat. If a
Federal action may affect a listed species or its critical habitat, the
responsible Federal agency must enter into consultation with the
Service.
Federal agency actions within the species' habitat that may require
conference or consultation or both as described in the preceding
paragraph include management and any other landscape-altering
activities on Federal lands or waters administered by the Service,
NMFS, U.S. Bureau of Reclamation, U.S. Army Corps of Engineers, U.S.
Department of Agriculture, or Federal Highway Administration.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to endangered wildlife.
The prohibitions of section 9(a)(1) of the Act, codified at 50 CFR
17.21, make it illegal for any person subject to the jurisdiction of
the United States to take (which includes harass, harm, pursue, hunt,
shoot, wound, kill, trap, capture, or collect; or to attempt any of
these) endangered wildlife within the United States or on the high
seas. In addition, it is unlawful to import; export; deliver, receive,
carry, transport, or ship in interstate or foreign commerce in the
course of commercial activity; or sell or offer for sale in interstate
or foreign commerce any species listed as an endangered species. It is
also illegal to possess, sell, deliver, carry, transport, or ship any
such wildlife that has been taken illegally. Certain exceptions apply
to employees of the Service, the NMFS, other Federal land management
agencies, and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.22. With regard to
endangered wildlife, a permit may be issued for the
[[Page 60972]]
following purposes: for scientific purposes, to enhance the propagation
or survival of the species, and for incidental take in connection with
otherwise lawful activities. The statute also contains certain
exemptions from the prohibitions, which are found in sections 9 and 10
of the Act.
It is our policy, as published in the Federal Register on July 1,
1994 (59 FR 34272), to identify to the maximum extent practicable at
the time a species is listed those activities that would or would not
constitute a violation of section 9 of the Act. The intent of this
policy is to increase public awareness of the effect of a proposed
listing on proposed and ongoing activities within the range of the
species proposed for listing. Based on the best available information,
the following actions are unlikely to result in a violation of section
9, if these activities are carried out in accordance with existing
regulations and permit requirements; this list is not comprehensive:
(1) Take of the longfin smelt outside the range of the DPS as
identified in figure 1;
(2) Take as a result of recreational fishing as permitted by the
State of California; and
(3) Recreational boating on open water areas of the San Francisco
Bay-Delta Estuary.
Based on the best available information, the following activities
may potentially result in a violation of section 9 of the Act if they
are not authorized in accordance with applicable law; this list is not
comprehensive:
Activities that the Service believes could potentially harm the
Bay-Delta longfin smelt and result in ``take'' include, but are not
limited to:
(1) Handling or collecting individuals of the DPS;
(2) Destruction/alteration of the Bay-Delta longfin smelt's habitat
by discharge of fill material, dredging, draining, ditching, or stream
channelization or diversion;
(3) Unauthorized diversion or alteration of surface flow into the
San Francisco Bay-Delta estuary by removal of freshwater from rivers,
streams wetlands, and other aquatic features;
(4) Pesticide applications in violation of label restrictions or
introduction of other contaminants that may degrade water quality of
the San Francisco Bay-Delta estuary; and
(5) Introduction of nonnative species that compete with or prey
upon the Bay-Delta longfin smelt or alter food resources for the DPS.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the San
Francisco Bay-Delta Fish and Wildlife Office (see FOR FURTHER
INFORMATION CONTACT).
II. Critical Habitat
Background
Section 4 of the Act (16 U.S.C. 1533) and the implementing
regulations in title 50 of the Code of Federal Regulations set forth
the procedures for determining whether a species is an endangered
species or a threatened species, issuing protective regulations for
threatened species, and designating critical habitat for threatened and
endangered species. In 2019, jointly with the National Marine Fisheries
Service, the Service issued final rules that revised the regulations in
50 CFR parts 17 and 424 regarding how we add, remove, and reclassify
threatened and endangered species and the criteria for designating
listed species' critical habitat (84 FR 45020 and 84 FR 44752; August
27, 2019). At the same time the Service also issued final regulations
that, for species listed as threatened species after September 26,
2019, eliminated the Service's general protective regulations
automatically applying to threatened species the prohibitions that
section 9 of the Act applies to endangered species (collectively, the
2019 regulations).
However, on July 5, 2022, the U.S. District Court for the Northern
District of California vacated the 2019 regulations (Center for
Biological Diversity v. Haaland, No. 4:19-cv-05206-JST, Doc. 168 (N.D.
Cal. July 5, 2022) (CBD v. Haaland)), reinstating the regulations that
were in effect before the effective date of the 2019 regulations as the
law governing species classification and critical habitat decisions.
Accordingly, in developing the analysis contained in this proposal, we
applied the pre-2019 regulations, which may be reviewed in the 2018
edition of the Code of Federal Regulations at 50 CFR 424.12(a)(1).
Because of the ongoing litigation regarding the court's vacatur of the
2019 regulations, and the resulting uncertainty surrounding the legal
status of the regulations, we also undertook an analysis of whether the
proposal would be different if we were to apply the 2019 regulations.
That analysis, which we described in a separate memo in the decisional
file and posted on <a href="https://www.regulations.gov">https://www.regulations.gov</a>, concluded that we would
have reached the same proposal if we had applied the 2019 regulations
because under either regulatory scheme we find that critical habitat is
prudent for the DPS of Bay-Delta longfin smelt.
On September 21, 2022, the U.S. Circuit Court of Appeals for the
Ninth Circuit stayed the district court's July 5, 2022, order vacating
the 2019 regulations until a pending motion for reconsideration before
the district court is resolved (In re: Cattlemen's Ass'n, No. 22-
70194). The effect of the stay is that the 2019 regulations are
currently the governing law. Because a court order requires us to
submit this proposal to the Federal Register by September 30, 2022, it
is not feasible for us to revise the proposal in response to the Ninth
Circuit's decision. Instead, we hereby adopt the analysis in the
separate memo that applied the 2019 regulations as our primary
justification for the proposal. However, due to the continued
uncertainty resulting from the ongoing litigation, we also retain the
analysis in this preamble that applies the pre-2019 regulations and we
conclude that, for the reasons stated in our separate memo analyzing
the 2019 regulations, this proposal would have been the same if we had
applied the 2019 regulations.
Critical habitat is defined in section 3 of the Act as:
(1) The specific areas within the geographical area occupied by the
species, at the time it is listed in accordance with the Act, on which
are found those physical or biological features
(a) Essential to the conservation of the species, and
(b) Which may require special management considerations or
protection; and
(2) Specific areas outside the geographical area occupied by the
species at the time it is listed, upon a determination that such areas
are essential for the conservation of the species.
Our regulations at 50 CFR 424.02 define the geographical area
occupied by the species as an area that may generally be delineated
around species' occurrences, as determined by the Secretary (i.e.,
range). Such areas may include those areas used throughout all or part
of the species' life cycle, even if not used on a regular basis (e.g.,
migratory corridors, seasonal habitats, and habitats used periodically,
but not solely by vagrant individuals).
Conservation, as defined under section 3 of the Act, means to use
and the use of all methods and procedures that are necessary to bring
an endangered or threatened species to the point at which the measures
provided pursuant to the Act are no longer necessary. Such methods and
procedures include, but are not limited to, all activities associated
with scientific resources management such as
[[Page 60973]]
research, census, law enforcement, habitat acquisition and maintenance,
propagation, live trapping, and transplantation, and, in the
extraordinary case where population pressures within a given ecosystem
cannot be otherwise relieved, may include regulated taking.
Critical habitat receives protection under section 7 of the Act
through the requirement that Federal agencies ensure, in consultation
with the Service, that any action they authorize, fund, or carry out is
not likely to result in the destruction or adverse modification of
critical habitat. The designation of critical habitat does not affect
land ownership or establish a refuge, wilderness, reserve, preserve, or
other conservation area. Such designation also does not allow the
government or public to access private lands. Such designation does not
require implementation of restoration, recovery, or enhancement
measures by non-Federal landowners. Where a landowner requests Federal
agency funding or authorization for an action that may affect a listed
species or critical habitat, the Federal agency would be required to
consult with the Service under section 7(a)(2) of the Act. However,
even if the Service were to conclude that the proposed activity would
result in destruction or adverse modification of the critical habitat,
the Federal action agency and the landowner are not required to abandon
the proposed activity, or to restore or recover the species; instead,
they must implement ``reasonable and prudent alternatives'' to avoid
destruction or adverse modification of critical habitat.
Under the first prong of the Act's definition of critical habitat,
areas within the geographical area occupied by the species at the time
it was listed are included in a critical habitat designation if they
contain physical or biological features (1) which are essential to the
conservation of the species and (2) which may require special
management considerations or protection. For these areas, critical
habitat designations identify, to the extent known using the best
scientific and commercial data available, those physical or biological
features that are essential to the conservation of the species (such as
space, food, cover, and protected habitat).
Under the second prong of the Act's definition of critical habitat,
we can designate critical habitat in areas outside the geographical
area occupied by the species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific data available. Further, our Policy on
Information Standards Under the Endangered Species Act (published in
the Federal Register on July 1, 1994 (59 FR 34271)), the Information
Quality Act (section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)),
and our associated Information Quality Guidelines provide criteria,
establish procedures, and provide guidance to ensure that our decisions
are based on the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific data available, to use primary and original sources
of information as the basis for recommendations to designate critical
habitat.
When we are determining which areas should be designated as
critical habitat, our primary source of information is generally the
information from the SSA report and information developed during the
listing process for the species. Additional information sources may
include any generalized conservation strategy, criteria, or outline
that may have been developed for the species; the recovery plan for the
species; articles in peer-reviewed journals; conservation plans
developed by States and counties; scientific status surveys and
studies; biological assessments; other unpublished materials; or
experts' opinions or personal knowledge.
Habitat is dynamic, and species may move from one area to another
over time. We recognize that critical habitat designated at a
particular point in time may not include all of the habitat areas that
we may later determine are necessary for the recovery of the species.
For these reasons, a critical habitat designation does not signal that
habitat outside the designated area is unimportant or may not be needed
for recovery of the species. Areas that are important to the
conservation of the species, both inside and outside the critical
habitat designation, will continue to be subject to: (1) conservation
actions implemented under section 7(a)(1) of the Act; (2) regulatory
protections afforded by the requirement in section 7(a)(2) of the Act
for Federal agencies to ensure their actions are not likely to
jeopardize the continued existence of any endangered or threatened
species; and (3) the prohibitions found in section 9 of the Act.
Federally funded or permitted projects affecting listed species outside
their designated critical habitat areas may still result in jeopardy
findings in some cases. These protections and conservation tools will
continue to contribute to recovery of the species. Similarly, critical
habitat designations made on the basis of the best available
information at the time of designation will not control the direction
and substance of future recovery plans, habitat conservation plans, or
other species conservation planning efforts if new information
available at the time of those planning efforts calls for a different
outcome.
Prudency Determination
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12) require that, to the maximum extent prudent
and determinable, the Secretary shall designate critical habitat at the
time the species is determined to be an endangered or threatened
species. Our regulations (50 CFR 424.12(a)(1)) state that a designation
of critical habitat is not prudent when any of the following situations
exist:
(i) The species is threatened by taking or other human activity and
identification of critical habitat can be expected to increase the
degree of such threat to the species; or
(ii) Such designation of critical habitat would not be beneficial
to the species. In determining whether a designation would not be
beneficial, the factors the Services may consider include but are not
limited to: Whether the present or threatened destruction,
modification, or curtailment of a species' habitat or range is not a
threat to the species, or whether any areas meet the definition of
``critical habitat.''
As discussed in the SSA report, there is currently no imminent
threat of collection or vandalism (identified under Factor B) for this
species, and identification and mapping of critical habitat is not
expected to initiate any such threat. In our SSA report for the Bay-
Delta longfin smelt, we determined that the present or threatened
destruction, modification, or curtailment of habitat or range is a
threat to Bay-Delta longfin smelt. Therefore, because none of the
circumstances enumerated in our regulations at 50 CFR 424.12(a)(1) have
been met, we have determined that the designation of critical habitat
is prudent for the Bay-Delta longfin smelt.
Critical Habitat Determinability
Having determined that designation is prudent, under section
4(a)(3) of the Act we must find whether critical habitat for the Bay-
Delta longfin smelt is determinable. Our regulations at 50 CFR
[[Page 60974]]
424.12(a)(2) state that critical habitat is not determinable when one
or both of the following situations exist:
(i) Data sufficient to perform required analyses are lacking, or
(ii) The biological needs of the species are not sufficiently well
known to identify any area that meets the definition of ``critical
habitat.''
We reviewed the available information pertaining to the biological
needs of the DPS and habitat characteristics where this DPS is located.
Careful assessments of the economic impacts that may occur due to a
critical habitat designation are not yet complete. Therefore, data
sufficient to perform required analyses are lacking, and we conclude
that the designation of critical habitat for the Bay-Delta longfin
smelt is not determinable at this time. The Act allows the Service an
additional year to publish a critical habitat designation that is not
determinable at the time of listing (16 U.S.C. 1533(b)(6)(C)(ii)).
Required Determinations
Clarity of the Rulemaking
We are required by E.O.s 12866 and 12988 and by the Presidential
Memorandum of June 1, 1998, to write all rules in plain language. This
means that each rule we publish must:
(1) Be logically organized;
(2) Use the active voice to address readers directly;
(3) Use clear language rather than jargon;
(4) Be divided into short sections and sentences; and
(5) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in ADDRESSES. To better help us
revise the proposed rule, your comments should be as specific as
possible. For example, you should tell us the numbers of the sections
or paragraphs that are unclearly written, which sections or sentences
are too long, the sections where you feel lists or tables would be
useful, etc.
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
It is our position that, outside the jurisdiction of the U.S. Court
of Appeals for the Tenth Circuit, we do not need to prepare
environmental analyses pursuant to the National Environmental Policy
Act (42 U.S.C. 4321 et seq.) in connection with regulations adopted
pursuant to section 4(a) of the Act. We published a notice outlining
our reasons for this determination in the Federal Register on October
25, 1983 (48 FR 49244). This position was upheld by the U.S. Court of
Appeals for the Ninth Circuit (Douglas County v. Babbitt, 48 F.3d 1495
(9th Cir. 1995), cert. denied 516 U.S. 1042 (1996)).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations with Native American Tribal
Governments; 59 FR 22951), E.O. 13175 (Consultation and Coordination
With Indian Tribal Governments), and the Department of the Interior's
manual at 512 DM 2, we readily acknowledge our responsibility to
communicate meaningfully with recognized Federal Tribes on a
government-to-government basis. In accordance with Secretarial Order
3206 of June 5, 1997 (American Indian Tribal Rights, Federal-Tribal
Trust Responsibilities, and the Endangered Species Act), we readily
acknowledge our responsibilities to work directly with Tribes in
developing programs for healthy ecosystems, to acknowledge that Tribal
lands are not subject to the same controls as Federal public lands, to
remain sensitive to Indian culture, and to make information available
to Tribes. No Tribal lands were identified within the range of the Bay-
Delta longfin smelt, and we did not receive any information during our
development of the SSA report for the DPS. We will continue to reach
out and coordinate with Tribal entities during the development of a
final determination for listing the Bay-Delta longfin smelt.
References Cited
A complete list of references cited in this rulemaking is available
on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a> and upon request from
the San Francisco Bay-Delta Fish and Wildlife Office (see FOR FURTHER
INFORMATION CONTACT).
Authors
The primary authors of this proposed rule are the staff members of
the Fish and Wildlife Service's Species Assessment Team and the San
Francisco Bay-Delta Fish and Wildlife Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, we propose to amend part 17, subchapter B of chapter
I, title 50 of the Code of Federal Regulations, as set forth below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.
0
2. Amend Sec. 17.11(h) by adding an entry for ``Smelt, longfin [San
Francisco Bay-Delta DPS]'' to the List of Endangered and Threatened
Wildlife in alphabetical order under FISHES to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
----------------------------------------------------------------------------------------------------------------
Listing citations and
Common name Scientific name Where listed Status applicable rules
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Fishes
* * * * * * *
Smelt, longfin [San Francisco Spirinchus U.S.A. (CA)....... E [Federal Register
Bay-Delta DPS]. thaleichthys. citation when
published as a final
rule].
* * * * * * *
----------------------------------------------------------------------------------------------------------------
[[Page 60975]]
Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2022-21605 Filed 10-6-22; 8:45 am]
BILLING CODE 4333-15-P
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</html>Indexed from Federal Register on October 7, 2022.
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