[Federal Register Volume 86, Number 78 (Monday, April 26, 2021)]
[Rules and Regulations]
[Pages 21950-21961]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-08466]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-HQ-ES-2017-0047; FF09E22000 FXES11180900000 212]
RIN 1018-BC83
Endangered and Threatened Wildlife and Plants; Listing the
Yangtze Sturgeon as an Endangered Species
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
endangered species status under the Endangered Species Act of 1973
(Act), as amended, for the Yangtze sturgeon (Acipenser dabryanus). Loss
of individuals due to overharvesting on the Yangtze River is the main
factor that contributed to the historical decline of the species.
Despite conservation efforts, this species is still currently in
decline, due primarily to the effects of dams and bycatch. This rule
adds the Yangtze sturgeon to the List of Endangered and Threatened
Wildlife.
DATES: This rule is effective May 26, 2021.
ADDRESSES: Comments and materials received, as well as supporting
documentation used in the preparation of this rule, are available for
public inspection at http://www.regulations.gov under Docket No. FWS-
HQ-ES-2017-0047.
FOR FURTHER INFORMATION CONTACT: Maricela Constantino, Acting Chief,
Branch of Delisting and Foreign Species, Ecological Services Program,
U.S. Fish and Wildlife Service, 5275 Leesburg Pike, MS: ES, Falls
Church, VA 22041; telephone 703-358-2171. If you use a
telecommunications device for the deaf (TDD), call the Federal Relay
Service at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Previous Federal Actions
On December 27, 2017, we published in the Federal Register (82 FR
61230) a 12-month finding and proposed rule to list the Yangtze
sturgeon (Acipenser dabryanus) as an endangered species under the Act.
A thorough review of the taxonomy, life history, ecology, and overall
viability of the Yangtze sturgeon is also presented in the species
status assessment (SSA) for the Yangtze sturgeon (Service 2017;
available at http://www.regulations.gov at Docket No. FWS-HQ-ES-2017-
0047), and a summary of this information, including the history of
previous federal actions, a summary of the species' description,
taxonomy, biology, life history, habitat, distribution, and historical
and current population, is provided in our December 27, 2017, proposed
rule (82 FR 61230).
Summary of Changes From the Proposed Rule
We received one comment from a peer reviewer providing additional
information regarding ongoing and new conservation efforts on the
Yangtze River, which include lengthening fishing bans within the
species' range and the commencement of restocking efforts on reaches
below Gezhouba Dam. We have incorporated this information into this
rule and have updated our species status assessment (SSA) report.
Supporting Documents
A species status assessment team prepared an SSA report for the
Yangtze sturgeon. The SSA team was composed of Service biologists, in
consultation with other species experts. The SSA report represents a
compilation of the best scientific and commercial data available
concerning the status of the species, including the impacts of past,
present, and future factors (both negative and beneficial) affecting
the species.
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
[[Page 21951]]
updating and clarifying the role of peer review of listing actions
under the Act, we sought peer review of the SSA report. The Service
sent the SSA report to six independent peer reviewers and received two
responses. The purpose of peer review is to ensure that our listing
determinations are based on scientifically sound data, assumptions, and
analyses. The peer reviewers have expertise in the biology, habitat,
and threats to the species.
Background
Presented below is a brief summary of the species' description,
life history, distribution, and historical and current population. A
more detailed examination of the information can be found in our SSA
and proposed rule (Service 2017, entire; 82 FR 61230, December 27,
2017).
Species Description
The Yangtze sturgeon is a freshwater fish species that attains a
maximum size of around 130 centimeters (4.3 feet (ft)) and a maximum
weight of about 16 kilograms (35 pounds) (Billiard and Lecointre 2000,
p. 368; Zhuang et al. 1997, pp. 257, 259). The species has a triangular
head, an elongated snout, and large blowholes (Gao et al. 2009b, p.
117). Yangtze sturgeons have tactile barbels at the front of their
mouths that they use to dig for food. On the dorsal side, Yangtze
sturgeons are dark gray, brownish-gray, or yellow-gray in color. The
rest of the body is milky white in color (Zhuang et al. 1997, p. 259).
Life History
Although the Yangtze sturgeon's life history is similar to other
sturgeon species, there are key differences. Based on the best
available information, much of what is known about the Yangtze
sturgeon's life history comes from research on the more numerous and
studied Chinese sturgeon due to similarities in morphology, taxonomy,
and life history between the two species. Yangtze sturgeons spawn in
the spring from March to April, with a smaller late fall/early winter
spawning period occurring from October to December (Qiwei 2010, p. 3;
Gao et al. 2009b, p. 117; Kynard et al. 2003, p. 28). Spawning
migration begins when water level, flow velocity, and silt content
enters a downward trend (Zhang H. et al. 2012, p. 4).
Juvenile sturgeons disperse around 100 to 200 kilometers (km) (62
to 124 miles (mi)) downstream from their spawning ground and arrive in
backwater pools and sandy shallows with low velocity flow and rich mud
and sand substrate where they feed on insects, aquatic plants, and
small fish (Zhang et al. 2011, p. 184; Zhuang et al. 1997, p. 259).
During the spring flood on the main stem of the Yangtze River,
juveniles will move to the tributaries to feed. Young sturgeons will
remain in these feeding reaches until they reach maturity (4 to 6 years
for males and 6 to 8 years for females) after which they begin
migrating upstream towards the spawning ground during the spring flood
(Zhuang et al. 1997, p. 261).
Historical Range
As its name implies, the Yangtze sturgeon is found in the Yangtze
River (Wu et al. 2014, p. 5). The river is more than 6,397 km (3,975
mi) in length and is divided into three segments. The upper reach,
which spans a total of about 4,300 km (2,671 mi), is further sub-
divided into two segments: The Jinsha River segment, which stretches
from the headwater in Yushu in the Tibetan Plateau to Yibin, a distance
of about 2,300 km (1,429 mi), and the upper Yangtze River, which
stretches from Yibin to the Three Gorges region at Yichang, a distance
of about 1,000 km (621 mi) (Cheng et al. 2015, p. 571; Jiang et al.
2008, p. 1471; Fu et al. 2003, p. 1651). The middle reach is from
Yichang to Hukou, a distance of about 950 km (590 mi). The Yangtze
River widens in this segment and is identified by multiple large lakes,
including Lake Dongting and Lake Poyang. The lower reach stretches from
Hukou to the mouth of the river at Shanghai, a distance of about 930 km
(577 mi) (Fu et al. 2003, p. 1651).
Historically, the Yangtze sturgeon was found in the lower portion
of the Jinsha River and the upper, middle, and lower reaches of the
Yangtze River, a distance of about 1,300 km (807 mi) (Wu et al. 2014,
p. 5). The majority of historical sightings occurred in the lower
Jinsha and upper Yangtze River with occasional sightings in the middle
and lower Yangtze (Zhuang et al. 1997, p. 259). The species has also
been found in major tributaries that feed into the upper Yangtze
including the Min, Tuo, and Jialing (Artyukhin et al. 2007, p. 370).
There have also been sightings of the species in Dongting Lake and
Poyang Lake in the middle and lower reaches, respectively (Zhuang et
al. 1997, p. 259). One sighting took place as far downstream as Anhui
province, a distance of more than 2,000 km (1,242 mi) downstream from
Yibin (Zhuang et al. 1997, p. 261). The species' spawning reach is
understood by Yangtze sturgeon researchers to have occurred from
Maoshui in the lower Jinsha River to Hejiang in the upper Yangtze River
(Zhang et al. 2011, p. 184).
Current Range
The Yangtze sturgeon's current range has been reduced to the upper
Yangtze River and its tributaries in the reaches between Yibin and
Yichang, a distance of about 1,000 km (621 miles) (Wu et al. 2014, p.
5; Dudgeon 2010, p. 128; Huang et al. 2011, p. 575; Zhang et al. 2011,
p. 181; Artyukhin et al. 2007, p. 370). The completion of the Gezhouba
Dam in 1981 at Yichang prevented the upstream migration of adults to
the species' spawning ground (Zhuang et al. 1997, p. 261). As a result
of the construction of Gezhouba Dam, the species may have been
extirpated in reaches below the dam (Li et al. 2015, p. 186; Zhu et al.
2008, p. 30). That said, from 2014-2017, fishermen below Gezhouba Dam
accidentally captured four adult Yangtze sturgeons, suggesting the
presence of a very small remnant population (Du 2017, pers. comm.). The
construction of the Three Gorges Dam and its reservoir, which began in
2003 and was completed in 2009, further reduced the species' range by
modifying reaches above Three Gorges Dam to a lentic (still water)
system (Chen D. et al. 2009, p. 341; Fu et al. 2003, p. 1650). Loss of
lotic (rapidly moving water) ecosystem reduces the quality of remaining
habitat for the species (Kynard 2016, pers. comm.; Cheng et al. 2015,
pp. 570, 576). On the lower Jinsha River, in the upstream portion of
the species' historical range, the construction of the Xiangjiaba Dam,
which was completed in 2008, limited the species' spawning ground to
areas below the dam (Zhang et al. 2011, pp. 183-184). The species
continues to ascend the major tributaries in the upper Yangtze,
including the Min, Tuo, and Jialing River (Huang et al. 2011, p. 575;
Artyukhin et al. 2007, p. 370).
Historical and Current Population
The Yangtze sturgeon was historically abundant and was commercially
harvested up to the 1970s (Lu et al. 2015, p. 89; Zhang et al. 2013, p.
409; Kynard et al. 2003, p. 27). The majority (80 percent) of harvest
of Yangtze sturgeon took place during the 1950s to the 1970s. However,
overharvesting during this time period led to a sharp decline in the
population size (Kynard et al. 2003, p. 27).
While there may have been natural recruitment of the species in the
1990s, no natural recruitment has been observed in the wild since the
2000s (Du et al. 2014, p. 1; Wu et al. 2014, p. 1). The population is
currently being repopulated by artificial restocking. Between the years
of 2010-2013, 7,030 Yangtze sturgeon juveniles were
[[Page 21952]]
released into the middle and upper Yangtze River in two to three
batches each year (Wu et al. 2014, p. 3). Restocking efforts have been
ongoing in the reaches below Gezhouba Dam since 2014 (Hu 2017, pers.
comm.). However, restocked sturgeons suffer from low fitness; most
notably, they lack the ability to survive to reproductive age. Capture
data obtained from the releases in 2010-2013 found that 95 days after
restocking, no restocked sturgeons were caught either by researchers or
by fishermen in the upper Yangtze River (Wu et al. 2014, pp. 3-5).
These results indicate that restocked sturgeon have a very low survival
rate. Although we do not have population estimates for the species,
based on the fact that there has been no observable natural
reproduction since the 2000s and the low survival rate of restocked
sturgeon, the species' population in the Yangtze River is likely to be
very low when compared to historical numbers (Du et al. 2014, p. 1; Wu
et al. 2014, p. 4).
Regulatory and Analytical Framework
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 expected response by the species,
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
foreseeable future extends only so far into the future as the Services
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 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.
Our proposed rule described ``foreseeable future'' as the extent to
which we can reasonably rely on predictions about the future in making
determinations about the future conservation status of the species. The
Service since codified its understanding of foreseeable future at 50
CFR 424.11(d) (84 FR 45020, August 27, 2019). In those regulations, we
explain the term ``foreseeable future'' extends only so far into the
future as the Service can reasonably determine that both the future
threats and the species' responses to those threats are likely. The
Service will describe the foreseeable future on a case-by-case basis,
using the best available data and taking into account considerations
such as the species' life-history characteristics, threat-projection
timeframes, and environmental variability. The Service need not
identify the foreseeable future in terms of a specific period of time.
These regulations did not significantly modify the Service's
interpretation; rather they codified a framework that sets forth how
the Service will determine what constitutes the foreseeable future
based on our long-standing practice. Accordingly, although these
regulations do not apply to the final rule for the Yangtze sturgeon
because it was proposed prior to their effective date, they do not
change the Service's assessment of foreseeable future for the Yangtze
sturgeon as contained in our proposed rule and in this final rule.
Analytical Framework
The SSA report documents the results of our comprehensive
biological status review for the species, including an assessment of
the potential threats to the species. The SSA report does not represent
a decision by the Service on whether the species should be listed as an
endangered or threatened species under the Act. It does, however,
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
[[Page 21953]]
full SSA report can be found at Docket FWS-HQ-ES-2017-0047 on http://www.regulations.gov.
To assess Yangtze sturgeon 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 species'
ecological requirements for survival and reproduction at the
individual, population, and species levels, and described the
beneficial and risk factors influencing the species' viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical
and current condition of the species' demographics and habitat
characteristics, including an explanation of how the species arrived at
its current condition. The final stage of the SSA involved making
predictions about the species' responses to positive and negative
environmental and anthropogenic influences. This process used the best
available information to characterize viability as the ability of a
species to sustain populations in the wild over time. We use this
information to inform our regulatory decision.
Summary of Biological Status and Threats
Below, we review the biological condition of the species and its
resources, and the threats that influence the species' current and
future condition, in order to assess the species' overall viability and
the risks to that viability.
Dams on the Yangtze River and Their Effects
The topography of the upper Yangtze River basin is characterized by
mountains of varying heights. The change in elevation between the upper
Yangtze to the lower Yangtze amounts to 3,280 meters (m) (10,761 feet
(ft)), which makes the upper Yangtze River an ideal place for
hydroelectric projects (Fan et al. 2006, p. 33). The growth of dam
construction in China has accelerated during the past decades. From the
1970s to the 1990s, an average of 4.4 large reservoirs (capacity
greater than 0.1 kilometers\3\ (km\3\)) were constructed per year. By
the 2000s, this number had increased to an average construction rate of
11.8 large reservoirs per year. By 2011, China possessed 552 large
reservoirs, 3,269 medium reservoirs (capacity of 0.01-0.1 km\3\), and
84,052 small reservoirs (capacity of 0.0001-0.01 km\3\); of this
number, the Yangtze River basin contained 45,000 dams and reservoirs,
including 143 dams having large reservoirs, or a quarter of all large
reservoirs in China (Miao et al. 2015, p. 2350; Mueller et al. 2008, p.
233). The construction of dams and reservoirs have multiple and broad
effects on the Yangtze sturgeon and its habitat, including limiting
connectivity between spawning and feeding reaches; altering water
temperature, water discharge, and velocity rates; and changing sediment
concentration.
Connectivity
Dam construction on Yangtze River limits the ability of the Yangtze
sturgeon to migrate between spawning and feeding reaches. Dam
construction on the Yangtze occurs on both the upstream and downstream
portion of the species' current range. In the middle Yangtze River, the
construction of Gezhouba Dam in 1981 prevented adults downstream of the
dam from being able to migrate to the species' spawning ground in the
upper Yangtze near Yibin (Miao et al. 2015, p. 2351; Dudgeon 2010, p.
128; Fang et al. 2006, p. 375; Zhuang et al. 1997, p. 261). Although
the reaches below Gezhouba Dam might be suitable for the species, at
present there has been no observed natural reproduction below Gezhouba
Dam (Du 2017, pers. comm.). In addition to Gezhouba Dam, the
construction of the Three Gorges Dam in 2003 created a reservoir that
affected individuals of the species upstream. The Three Gorges Dam
reservoir, which extends 600 km upstream from the dam, transformed the
area into unsuitable habitat for Yangtze sturgeon (Kynard 2016, pers.
comm.; Cheng et al. 2015, p. 570; Miao et al. 2015, p. 2351). As a
result of the construction of the reservoir, the species now rarely
swims downstream to reaches below Chongqing. The result is the species'
current range is concentrated in the 500-km reach between the Yibin and
Chongqing (Wu et al. 2015, p. 5).
Meanwhile, in the upstream portion of the species' range, the
construction of Xiangjiaba Dam on the lower Jinsha River segment
occurred on part of the historical spawning reach of the Yangtze
sturgeon. Xiangjiaba Dam is a barrier to all fish species and prevents
migration to areas above or below the dam (Wu et al. 2014, p. 2).
However, the species may be able to use spawning reaches below the dam
(Fan et al. 2006, p. 36). That said, a dam located upstream from the
species' habitat affects the species downstream by altering water
temperature and sedimentation rate, which we discuss below (Fan et al.
2006, p. 36).
In addition to dams currently present on the lower Jinsha and upper
Yangtze River, in the early 2000s, a proposal was presented for the
construction of the Xiaonanhai Dam, which would be located upstream
from Chongqing. If built, this dam would create a barrier between the
species' last known spawning ground and feeding reach, which, depending
on design, could have a significant negative impact on the species
(Cheng et al. 2015, p. 579). However, at present, China's Ministry of
Environmental Protection has rejected the proposal and any future dam
projects on the last stretch of free-flowing Yangtze River due to
environmental impacts (Chang 2016, pers. comm.; Kynard 2016, pers.
comm.; Mang 2015, unpaginated).
While the rejection of the proposal to construct the Xiaonanhai Dam
will allow continued connectivity between the spawning and feeding
reach for the Yangtze sturgeon, the country's twelfth 5-year plan
stated that renewable resources should make up 15 percent of all energy
generated in China with 9 percent coming from hydroelectric sources.
This plan translates to an additional 230 gigawatts (GW) of power
generated via hydroelectric dams. This target is a very ambitious one,
given that Three Gorges Dam generates 18 GW of power per year (Dudgeon
2011, p. 1496). Furthermore, although the plan to construct the
Xiaonanhai Dam has been rejected, plans to construct dams on the Jinsha
River as part of a 12-dam cascade are still proceeding (Dudgeon 2010,
p. 129).
Water Temperature
Dams negatively affect the reproductive success of Yangtze sturgeon
by altering water temperature flowing through the species' habitat.
Water temperature influences the reproductive success of the Yangtze
sturgeon at two stages in its life cycle: Commencement of spawning
migration and egg survival. Spawning migration of
[[Page 21954]]
the Yangtze sturgeon will not start until the water temperature reaches
18 degrees Celsius ([deg]C) (64.4 degrees Fahrenheit ([deg]F)) (Cheng
et al. 2015, p. 578). Historically, before the construction of the
Xiangjiaba and other dams on the lower Jinsha, the water temperature
reached 18 [deg]C (64.4 [deg]F) around April. However, the construction
of the dams stratified the water table. As most dams on the Yangtze are
designed to release cold water located at the bottom of the dams, the
spawning season for the Yangtze sturgeon could be delayed by more than
a month (Deng et al. 2006 and Wang et al. 2009, as cited in Cheng et
al. 2015, p. 578). This delay shortens the maturing season for
juveniles and is likely to reduce the species' survival rate.
Additionally, if the water remains too cold for too long, sturgeon eggs
will not mature, resulting in total loss of reproduction for that
season (Kynard 2016, pers. comm.).
Water Discharge and Velocity
By altering discharge rates, dams affect the Yangtze sturgeon's
reproductive success by affecting the timing of spawning migration. The
species' spawning migration begins when flow rate increases during the
spring flood (Zhuang et al. 1997, p. 261). At Yichang, the most
downstream portion of the Yangtze sturgeon's current range, the mean
discharge rate from 1983 to 2004 (before the construction of Three
Gorges Dam) was between 10,000 m\3\ per second (/s) and 17,000 m\3\/s.
After the construction of the Three Gorges Dam, mean flow rate varies
between 6,414 m\3\/s in low flow years to 12,780 m\3\/s in high flow
years (Chen and Wu 2011, p. 384). For Chinese sturgeon, successful
spawning occurs when water discharge is between 7,000 and 26,000 m\3\/
s. This means that although the flow rate during high flow years
remains in the optimal discharge rate for Chinese sturgeon spawning,
discharge rates during low flow years are below the flows needed for
spawning, and thus are likely to have a negative impact on spawning
success rates (Chen and Wu 2011, p. 385). Given the similarities in the
genetic and life history between the Yangtze and Chinese sturgeon, the
reduction in discharge rate is likely to negatively affect the spawning
success rate of the Yangtze sturgeon on reaches below the Three Gorges
Dam as well.
While we do not have long-term historical data for the optimal
water discharge rate for the Yangtze sturgeon at Yibin, the flow rate
at Chongqing during the years 1950-2000 was between 4,540 m\3\/s and
11,000 m\3\/s (Zhang et al. 2011, p. 183). Since Chongqing is farther
upstream from Yichang, this flow rate may be the river's natural rate
at this section of the Yangtze. However, following the impoundment by
the Xiangjiaba Dam in October 2012 and the Xiluodo Dam in May 2013,
discharge in the lower Jinsha has declined more than 50 percent,
suggesting that the current flow rate is likely to be lower than the
flow rate between 1950 and 2000 (Cheng et al. 2015, p. 577). The Jinsha
River feeds into the upper Yangtze River. This means that a reduction
in flow rate on the Jinsha will also reduce the flow rate on the upper
Yangtze River. Given that the Yangtze sturgeon is closely related to
the Chinese sturgeon, a reduction of flow rate by over 50 percent could
have a significant negative impact on the reproductive success rate of
the Yangtze sturgeon given its already tenuous biological status.
Sedimentation Concentration
In addition to affecting spawning of Yangtze sturgeon, dams affect
the condition of the species' spawning ground through changes in the
water velocity and sedimentation load. Because reproductive success of
sturgeon is tied to the amount of suitable habitat, a reduction in
habitat area can reduce the reproductive success of the species (Ban et
al. 2011, p. 96; Bemis and Kynard 1997, p. 169). Specifically, flow
rates affect the Yangtze sturgeon by affecting the sedimentation
concentration in the water and on the riverbed. As noted before,
Yangtze sturgeon lay their eggs on the interstitial spaces between
rocks and boulders. The makeup of the riverbed needs to contain the
right concentration of small pebbles and larger boulders to provide
sufficient space for adherence and aeration of the eggs (Du et al.
2011, pp. 261-262; Bemis and Kynard 1997, p. 169).
Historically, discharge rates and sedimentation load were aligned
with precipitation rates: A low discharge rate results in a low
sedimentation load, while high discharge rates lead to a higher
sediment load, as high flows are able to transport more sediments
downstream (Chen Z. et al. 2001, pp. 88-89). However, with dams
constructed along the lower Jinsha and Yangtze Rivers, discharge rate
and sedimentation rate have become misaligned. While discharge rates
typically remain aligned with the precipitation rate, the sedimentation
load pattern displays a 2-month delay due to sediment being trapped
behind the dams. When the spring flood occurs, numerous dams release
highly concentrated sediment downstream all at once, resulting in an
asymmetrical sediment load pattern (Chen Z. et al. 2001, p. 90). The
effects of sediment load patterns on the species' habitat occur at two
stages: Release of sediments during high river stages and reduced
sediment size and load over time (Dudgeon 2011, pp. 1488, 1495).
The Jinsha River dams trap up to 82 percent of the sediment during
the winter months, resulting in ``clean'' (i.e., sediment-free) water
flowing downstream. This ``clean'' water lacks nutrients and may
decrease the food supply for the Yangtze sturgeon over the winter
months (Cheng et al. 2015, p. 578). During the subsequent spring flood,
the release of concentrated sediment from dams likely results in
sediment filling in all the interstitial spaces in the spawning
habitat, thereby reducing available spawning habitat for that season.
Despite the spring release of concentrated sediments, sediment load
is expected to decline over time. At Yichang, sediment load per year
has decreased from 530 Megatonnes (Mt) (530 million metric tons) per
year in the 1950s-1960s, to 60 Mt (60 million metric tons) per year
after 2003. Additionally, suspended sediment at Yichang below Three
Gorges Dam has decreased in size from 8-10 micrometers in 1987-2002 to
3 micrometers after 2003 (Yang et al. 2011, pp. 16-17). Reduction in
sediment size can lead to increased embeddedness of available
interstitial space, which prevents the adherence of eggs to the river
bottom and reduces the quality of remaining spawning habitats. At the
reaches below Gezhouba Dam, sedimentation has reduced available
interstitial space by as much as 50 to 70 percent (Du et al. 2011, p.
262).
Summary of Effects of Dams on the Yangtze Sturgeon
Dam construction in the middle Yangtze and lower Jinsha has
restricted the species' range to the reaches of the Yangtze between
Yibin and Yichang (Wu et al. 2014, p. 5). These projects prevented the
migration of the species upstream and downstream of the dams. Although
there is currently access between the species' remaining spawning and
feeding grounds, the condition of the remaining habitat is likely to be
negatively affected by changes to the river flow and sedimentation
rate. The formation of the Three Gorges reservoir has transformed the
600-km reach above the dam into a lentic (still water) system,
resulting in unsuitable habitat for the species (Kynard 2016, pers.
comm.; Cheng et al.
[[Page 21955]]
2015, pp. 570, 576). As a result, Yangtze sturgeon rarely use habitat
downstream from Chongqing (Wu et al. 2014, p. 5).
Upstream from the species' current range, the construction of the
Xiluodu and Xiangjiaba Dams are likely to negatively affect the
reproductive success of the Yangtze sturgeon. Through the release of
cold water during the spring flood, the dam can delay the spawning
migration of the sturgeon, which will shorten the maturation time for
juveniles and possibly prevent the successful maturation of eggs
altogether (Kynard 2016, pers. comm.; Cheng et al. 2015, p. 578).
Alteration to sediment concentration in both the short term and long
term reduces the quality of remaining habitat (Du et al. 2011, p. 262).
Given the lack of observed natural reproduction of the species in the
upper Yangtze, present and future dam construction could significantly
affect the viability of the species.
Overfishing (Historical) and Bycatch (Current)
Historically, the Yangtze sturgeon was commercially harvested on
the Yangtze River. In the 1970s, 5,000 kilograms (5.5 tons) of Yangtze
sturgeons were caught in the spring season at Yibin (Zhuang et al.
1997, p. 262). Since then, however, the population of Yangtze sturgeon
has declined significantly (Zhang et al. 2013, p. 409). There are
multiple reasons for this decline: Fishermen use fine mesh nets that
prevent smaller fish, weighing as little as 50 grams (1.7 ounces), from
being able to escape; the number of fishing boats in the Yangtze River
increased from 500 in the 1950s to 2,000 by 1985; and more than 140,000
fishermen currently depend on the river for a living. Furthermore, the
fishing season historically overlapped with the main spawning season of
the Yangtze sturgeon (Yi 2016, p. 1; Fan et al. 2006, p. 37; Zhuang et
al. 1997, p. 262). The replacement of bamboo and reed gear with gear
made from synthetic fibers further contributed to a higher catch rate
of sturgeons (Chen D. et al. 2009, p. 346).
Despite attempts to help conserve the species by restocking,
restocked juveniles experience very low survival rates (Wu et al. 2014,
p. 4). From 2010 to 2013, restocking operations released 7,030
juveniles into the upper Yangtze River main stem. Subsequent bycatch
between 2010 and 2013 recorded a total of 112 sturgeons caught,
indicating a very low survival rate of stocked juveniles (Wu et al.
2014, p. 3). These results suggest that although other factors also
played a role in low survival rate of juveniles, the existing bycatch
rate continues to put pressure on the survival of the species (Wu 2016,
pers. comm.; Wu et al. 2014, p. 4).
Riverbed Modification
To reproduce successfully, the Yangtze sturgeon requires the river
substrate to contain a suitable concentration of sediment (Du et al.
2011, p. 257). Alteration of the riverbed has reduced the reproductive
success of this species. To improve navigation on the lower Jinsha and
upper Yangtze River, multiple projects, including sand and gravel
extraction operations, were implemented on the reaches between Shuifu
and Yibin, and Yibin and Chongqing (Zhang et al. 2011, p. 184). Between
2005 and 2009, $44 million (converted to U.S. dollars) were invested to
improve the navigation between Yibin and Chongqing. These investments
have led to the modification of 22 riffles (a shallow section of a
stream or river with rapid current and a surface broken by gravel,
rubble, or boulders) on the upper Yangtze and the deepening of the
channel from 1.8 m (5.9 ft) to 2.7 m (8.8 ft) (Zhang et al. 2011, p.
184). Additionally, up to 10, 6, and 3 river dredge ships operate in
the Yangtze River, the Jinsha River, and the Min River, respectively.
The operations of these ships alter the bottom topography of the
riverbeds, which results in the loss of benthic (bottom-dwelling)
habitat and spawning ground for many fish species, including the
Yangtze sturgeon (Fan et al. 2006, p. 37). These projects are occurring
on or near current Yangtze sturgeon spawning and feeding grounds from
Yibin to Hejiang. Thus, these operations will continue to reduce the
quality and quantity of remaining habitat (Zhang et al. 2011, p. 184).
Industrial Pollution
As a benthic predator, the Yangtze sturgeon is exposed to higher
concentrations of industrial pollution than many other fish species
(Yujun et al. 2008, pp. 341-342). While we are not aware of any studies
that analyze the impacts of industrial pollution on Yangtze sturgeon
specifically, there have been studies on Chinese sturgeon and other
sturgeon species. Industrial pollutants such as triphenyltin (TPT)
affect the reproductive success of the Chinese sturgeon. TPT, used in
paint on ship hulls and in fishnets in China, can be absorbed into the
eggs of Chinese sturgeon, resulting in increased deformities, including
abnormal development and skeletal and morphological deformities in
embryos (Hu et al. 2009, pp. 9339-9340).
A study on TPT exposure to 2- to 3-day-old Chinese sturgeon larvae
found that 6.3 percent showed skeletal/morphological deformities and
1.2 percent had no eyes or only one eye. At the same time, larvae from
spawning hatches of captured adults showed skeletal/morphological
deformities of 3.9 percent and 1.7 percent that had only one eye or no
eyes. Given the rate of deformities found in this study, reproduction
in the studied Chinese sturgeon was reduced by 58.4 to 75.9 percent (Hu
et al. 2009, p. 9342). Because the Yangtze and Chinese sturgeon are
closely related species, the presence of TPT in the upper Yangtze River
is likely reducing the reproductive success of the Yangtze sturgeon at
a similar rate.
In addition to TPT, the presence of endocrine disruptor compounds
(EDC) affects Chinese sturgeon by inducing declining sperm activity,
intersex testis-ova, and a decline in the male to female ratio in the
population (An and Hu 2006, p. 381). A study on EDC found that the
concentration of EDC in the Yangtze River from industrial discharge
(1.55 to 6.85 micrograms per liter) is very high and could have a
detrimental impact on sturgeon in the river.
As a result of rapid industrialization along the Yangtze River,
higher concentrations of heavy metals are found in the river (Yujun et
al. 2008, p. 338). A high concentration of heavy metals leads to
greater accumulation of these metals in all aquatic organisms (Yujun et
al. 2008, p. 339). The toxicity effect of heavy metal accumulation is
especially pronounced in zoobenthic predators, like the Yangtze
sturgeon, because they occupy a higher position in the food chain. The
result is that by consuming smaller prey species that have absorbed
heavy metal, zoobenthic predators accumulate heavy metals inside their
bodies (Yujun et al. 2008, p. 346). Given that the heavy metal
concentration is highest in benthic animals, especially zoobenthic
predators like the sturgeon, the effect of heavy metals on the sturgeon
could be more pronounced than in other aquatic species (Yujun et al.
2007, p. 341; An and Hu 2006, p. 381). Despite the known impacts on
captured Chinese sturgeon, we currently do not have evidence of
population-level impacts of EDC or heavy metals on the wild Yangtze
sturgeon population. That said, even though we have no evidence of
morphological deformities in wild sturgeon, it is likely that
industrial pollution does have an effect on the reproductive success of
wild sturgeon.
[[Page 21956]]
Hybridization With Displaced Native and Nonnative Sturgeon
Despite the decline in wild fishery yields, the Yangtze basin
remains one of the major centers of China's aquaculture industry.
Fishery yields from the basin account for 65 percent of total
freshwater fisheries production in China (Shen et al. 2014, p. 1547;
Chen D. et al. 2009, p. 338). In the past 30 years, sturgeon
aquaculture in China has risen significantly. Although commercial
aquaculture for sturgeon only started in the 1990s, by 2006, production
had reached 17,424 tons, which accounts for 80 percent of the world
total production (Shen et al. 2014, p. 1548). The growth of the
aquaculture industry in China saw aquaculture farms constructed across
all branches of the Yangtze River (Li R. et al. 2009, p. 636). Sturgeon
species that are commonly used in the aquaculture industry include the
Amur sturgeon (Acipenser schrenckii), kaluga (Huso dauricus), and other
Amur River sturgeon hybrids (Li R. et al. 2009, p. 636). However, none
of these commonly cultured species is native to the Yangtze River. The
existing fishing management regulations are not adequate to address the
threat of hybridization, and the regulations that do exist are not
enforced. In particular, non-native aquaculture sturgeon and hybridized
aquaculture sturgeon are escaping from sturgeon farms into the wider
river system (Li R. et al. 2009, p. 636). The result is a comingling of
native, exotic, and hybrid sturgeon species which could have a negative
impact on the Yangtze sturgeon (Shen et al. 2014, p. 1549; Li R. et al.
2009, p. 636).
Currently, no aquaculture efforts in China use native strains of
sturgeon. Because no farms in China focus on raising native stock in
large enough numbers, this system creates shortages of parental stock
of native sturgeon. In response to this shortage, farmers crossbreed
wild-caught sturgeon with any sturgeon species available, including
nonnative species (Xiong et al. 2015, p. 658; Li R. et al. 2009, p.
636). For example, in 2006, there was a shortage of Siberian sturgeon
(Acipenser baerii) in China. Farmers then started crossbreeding
Siberian sturgeon with Russian sturgeon (A. gueldenstaedtii), Sterlet
sturgeon (A. ruthenus), and Amur sturgeon (A. schrenckii) (Li R. et al.
2009, p. 636). Crossbreeding of sturgeon species in China alters the
makeup of the wild population. Of the 221 young sturgeons captured on
the Yangtze River in 2006, 153 were hybrids, which accounted for 69.9
percent of total sturgeons caught (Li R. et al. 2009, p. 636). This
information indicates that farmed hybrids are escaping into the river
system. Although this study was conducted in the lower Yangtze River
below the range of the Yangtze sturgeon, because sturgeon aquaculture
occurs across the Yangtze River system, it is likely that hybridization
is occurring in the upper Yangtze River as well.
The uncontrolled hybridization of native and nonnative species on
the Yangtze alters the population dynamics between hybrids and native
stocks. Hybridization may reduce the fitness of the overall population
or replace a population of native fish with hybrids (Shen et al. 2014,
p. 1549; Li R. et al. 2009, p. 636). Hybridization may also result in
hybrids with better fitness than wild stock that outcompete the wild
native stock of Yangtze sturgeon for habitat and resources. When native
fish are unavailable, farmers tend to import nonnative fish that have
more desirable characteristics, such as a higher growth rate and better
adaptability. These nonnative sturgeons are bred with available native
sturgeon to produce hybrids. These hybrids oftentimes escape or are
accidentally introduced into the wild and then compete with the Yangtze
sturgeon for resources (Xiong et al. 2015, pp. 657-658). Although
hybridization is likely occurring all along the Yangtze River, we
currently do not have information on the rate of hybridization in
sturgeon in the upper Yangtze or how significant the effects are on the
Yangtze sturgeon. Given that hybridized sturgeons make up 69.9 percent
of sturgeons found in the studied area, it is likely that sturgeon
hybrids are competing, and will likely continue to compete, with native
stocks for habitat and resources throughout the Yangtze River system.
Management Efforts
As a result of overfishing and the construction of Gezhouba Dam in
1981, the population of Yangtze sturgeon has continued to decline (Du
et al. 2014, p. 1; Wu et al. 2014, p. 1; Zhang H. et al. 2011, p. 181).
In response to the decline of the species, national and local officials
have embarked on a number of initiatives to help conserve the species.
These initiatives include increasing legal protection for the Yangtze
sturgeon, creating and designating part of the species' range as a
protected area, and repopulating the species in the wild through
restocking (Zhang H. et al. 2011, p. 181; Fan et al. 2006, p. 35; Wei
et al. 2004, p. 322).
Legal Protections
In response to the decline of the Yangtze sturgeon, in 1989,
China's State Council added the Yangtze sturgeon to the National Red
Data Book for Threatened Chinese Fish as a Class I Protected Animal (Wu
et al. 2014, p. 1; Zhang H. et al. 2011, p. 181; Dudgeon 2010, p. 128;
Wei et al. 2004, p. 322; Zhuang et al. 1997, p. 258). Animals listed as
a Class I species are protected from certain activities, including
hunting, capturing, or killing, for both commercial and personal uses.
Scientific research, domestication, breeding, and exhibition are
exempted (Wei et al. 2004, p. 322). Transportation of Class I-listed
species requires approval from the Department of Wildlife
Administration. Import or export of Class I aquatic species is
regulated by the Fisheries Bureau of the Minister of Agriculture (Wei
et al. 2004, p. 323).
In addition to its listing under national law, the species has also
been included in Appendix II of the Convention on International Trade
in Endangered Species of Wild Fauna and Flora (CITES) since 1998
(Ludwig 2008, p. 5; CITES 1997, pp. 152-153). A query of the CITES
trade database does not show any records of legal international trade
in Yangtze sturgeon from 1975 to 2017 (CITES 2019). International trade
in CITES species is regulated via a permit system. Under Article IV of
CITES, export of an Appendix-II specimen requires a prior grant and
presentation of an export permit. Export permits for Appendix-II
specimens are only granted if the Management Authority of the State of
export is satisfied that the specimens were lawfully obtained and if
the Scientific Authority of the State of export has advised that the
trade is not detrimental to the survival of the species in the wild.
For any living specimen, the Management Authority of the State of
export must also be satisfied that the specimen will be so prepared and
shipped as to minimize the risk of injury, damage to health, or cruel
treatment. Re-export of an Appendix-II specimen requires the prior
grant and presentation of a re-export certificate, which is only
granted if the Management Authority of the State of re-export is
satisfied that the specimen was imported into that State in accordance
with CITES and, for any living specimen, that the specimen will be so
prepared and shipped as to minimize the risk of injury, damage to
health, or cruel treatment. Certain exemptions and other special
provisions relating to trade in CITES specimens are also provided in
Article VII of CITES. In the United States, CITES is
[[Page 21957]]
implemented through the Act and regulations at 50 CFR part 23.
Additionally, since 2003, a fishing ban on all fish species has
been implemented in the upper Yangtze River from February 1 to April
30. Starting in 2017, the fishing ban was changed and extended from
March to June (Du 2017, pers. comm.). One of the effects of this ban is
a reduction in the bycatch of Yangtze sturgeon, as the time period of
the ban coincides with the spawning season of the Yangtze sturgeon
(Chen D. et al. 2012, p. 532; Chen D. et al. 2009, p. 348).
Despite the implementation of legal protection for the species, the
current regulatory mechanisms for the species have several
shortcomings. China currently does not have a specialized, dedicated
agency to manage fisheries resources across the country. Riverine
resource management is maintained at local levels, which are often
located in major population centers, far away from the fishery resource
(Chen D. et al. 2012, p. 541). In the case of Yangtze sturgeon, these
different jurisdictions have variations in regulation and conservation
goals for the Yangtze River ecosystem, which limits the coordination of
species-conservation efforts and the overall effectiveness of managing
species conservation across the Yangtze River basin (Chen D. et al.
2012, p. 541).
In addition to a lack of a specialized body or other effective
basin-wide conservation efforts, lack of funding is a major problem for
local jurisdictions. Enforcement officers often lack basic equipment,
such as boats, to carry out fishing regulations within the fishery
(Chen D. et al. 2012, p. 541). Additionally, while commercial
harvesting of the species is prohibited, bycatch is still occurring and
may still be too high to sustain a wild breeding population (Zhang H.
et al. 2011, p. 184). The new seasonal fishing ban implemented in 2017
has the potential to reduce bycatch (Du 2017, pers. comm.). However,
the positive effects from a fishing ban on the Yangtze River may be
limited, given the fact that entire stretches of the river cannot be
closed off to fishing due to the importance of the river to the
economic well-being of riverside communities (Fan et al. 2006, p. 38).
Protected Areas
To offset the effects of habitat loss due to dams, in 2000, China's
State Department established the National Reserve of Hejiang-Leibo
Reaches of the Yangtze River for Rare and Endangered Fishes (Zhang H.
et al. 2011, p. 181; Fan et al. 2006, p. 35). The reserve is located on
the upper Yangtze River on the reaches between Xiangjiaba Dam and the
city of Chongqing. This reserve is intended to protect 3 imperiled fish
species, the Yangtze sturgeon, the Chinese paddlefish (Psephurus
gladius), and the Chinese high-fin banded shark (Myxocyprinus
asiaticus), as well as 37 other endemic fish species (Fan et al. 2006,
p. 35). In 2005, the reserve was expanded to mitigate the impact from
current and future dam constructions (Zhang H. et al. 2011, pp. 181-
182). While the reserve plays an important role in protecting wildlife
within its borders, expansion of the hydroelectric projects in the
lower Jinsha River and upper Yangtze outside the protected area is
likely to undermine the effectiveness of the reserve. In order to
facilitate economic growth, China has decentralized authority for
infrastructure development from the state to local municipalities. This
decentralized model has resulted in provincial governments prioritizing
economic growth over environmental impacts (Dudgeon 2011, p. 1496).
Since 2003, hydroelectric projects in China are subject to
environmental assessments and approval from the Ministry of
Environmental Protection (Ministry) (Dudgeon 2011, p. 1496). However,
this approval is routinely ignored even by nationally owned
corporations. For example, in 2004, China Three Gorges Corporation
(CTGC) began construction of the Xiluodu Dam in the Lower Jinsha
without obtaining permission from the Ministry (Dudgeon 2011, pp. 1496-
1497). In response, the Ministry suspended work on the dam in 2005.
However, despite initial reservations about the lack of an
environmental impact assessment, the Ministry quickly compiled reports
and allowed the dam construction to proceed (Dudgeon 2011, p. 1499).
Additionally, in 2009, the Ministry gave the authority to build two
additional dams on the Jinsha segment after a brief suspension (Dudgeon
2010, p. 129). Overall, these temporary suspensions of construction
have done little to slow down the pace of dam development. In addition
to dam construction occurring outside the reserve, there was also a
case of dam construction occurring within the reserve. In 2011, CTGC
began constructing the Xiangjiaba Dam on the Lower Jinsha. The location
of this dam was within the 500-km boundary of the National Reserve of
Hejiang-Leibo Reaches. The CTGC successfully petitioned the State
Council to redraw the boundaries of the reserve to exclude the section
of the river where the Xiangjiaba Dam is located (Dudgeon 2011, p.
1500; Dudgeon 2010, p. 129). The reserve, now renamed the National
Natural Reserve Area of Rare and Special Fishes of the Upper Yangtze
River, encompasses the reaches below the Xiangjiaba Dam from Yibin to
Chongqing, as well as the tributaries that feed into the Yangtze (Zhang
H. et al. 2011, p. 182; Fan et al. 2006, p. 35). The redrawing of the
area of the reserve to accommodate the construction of Xiangjiaba Dam
lends further evidence that local governments are prioritizing growth
over environmental impacts. The construction of the Xiangjiaba Dam led
to the impoundment of the reach upriver, which will affect the flow and
sedimentation rate downstream (Cheng et al. 2015, p. 577; Dudgeon 2011,
p. 1500). Given the lack of natural reproduction of the Yangtze
sturgeon and future impacts from the dam, it is unlikely that the
current boundary of the reserve will be sufficient to maintain a wild
breeding population of this species (Kynard 2016, pers. comm.; Dudgeon
2011, p. 1500).
Restocking
As a result of the decline of the species, controlled reproduction
and release of juvenile Yangtze sturgeon has occurred every year since
2007 (Zhang H. et al. 2011, p. 181). Between 2007 and 2012, more than
10,000 Yangtze sturgeon juveniles were released into the upper Yangtze
on reaches downstream from Xiangjiaba Dam (Wu et al. 2014, p. 1). In
2014, restocking was started on the reaches below Gezhouba Dam (Du
2017, pers. comm.). While this number is relatively small in comparison
with the 6 million Chinese sturgeon that have been released since 1983,
the restocking of the Yangtze sturgeon represents efforts by local and
state officials to try to maintain the species in the wild (Chen D. et
al. 2009, p. 349).
Despite the efforts to restock the Yangtze sturgeon in the wild,
current restocking efforts are unsuccessful (Wu et al. 2014, p. 4). No
juveniles were caught 95 days after release, indicating that released
sturgeon experienced a very high mortality rate (Wu et al. 2014, p. 4).
There are multiple possible reasons for the limited success of current
restocking efforts, including poor breeding and rearing techniques that
result in progeny with low survival rates in the wild, high bycatch
rate, and loss or deterioration of remaining habitats (Cheng et al.
2015, pp. 579-580; Du et al. 2014, p. 2; Shen et al. 2014, p. 1549;
Zhang H. et al. 2011, p. 184). Thus, despite attempts to conserve the
species in the wild through restocking, with all the other forces
acting on the
[[Page 21958]]
Yangtze sturgeon, it is unlikely that current restocking efforts are
adequate to improve the species' condition in the wild.
Stochastic (Random) Events and Processes
Species endemic to small regions, or known from few, widely
dispersed locations, are inherently more vulnerable to extinction than
widespread species because of the higher risk from localized stochastic
(random) events and processes, such as industrial spills and drought.
These problems can be further magnified when populations are very
small, due to genetic bottlenecks (reduced genetic diversity resulting
from fewer individuals contributing to the species' overall gene pool)
and random demographic fluctuations (Lande 1988, pp. 1455-1458; Pimm et
al. 1988, p. 757). Species with few populations, limited geographic
area, and a small number of individuals face an increased likelihood of
stochastic extinction due to changes in demography, the environment,
genetics, or other factors, in a process described as an extinction
vortex (a mutual reinforcement that occurs among biotic and abiotic
processes that drives population size downward to extinction) (Gilpin
and Soul[eacute] 1986, pp. 24-25). The negative impacts associated with
small population size and vulnerability to random demographic
fluctuations or natural catastrophes can be further magnified by
synergistic interactions with other threats.
The Yangtze sturgeon is known from a single geographic population
in the upper Yangtze River and its tributaries (Zhang et al. 2011, pp
181-182; Zhuang et al. 1997, p. 259). As a result, the species is
highly vulnerable to stochastic processes and is negatively affected by
these processes. In March 2000, for example, the Jinguang Chemical
Plant, located on the Dadu River (a tributary of the Yangtze River),
was found to be releasing yellow phosphorous into the Yangtze. This
substance is highly toxic to aquatic organisms, including the Yangtze
sturgeon (Chen D. et al. 2009, p. 343). Another spill in 2006 on the
Yuexi River, which also feeds into the Yangtze, involved mercury being
released into the river (Worldwatch Institute 2006, entire). These and
other incidents, combined with the fact that the Yangtze River system
is home to a large number of chemical plants, suggest that the risk of
industrial spills is quite high. Therefore, stochastic processes will
have negative impacts on the species in combination with other factors
such as habitat modification and loss, and bycatch.
We note that, by using the SSA framework to guide our analysis of
the scientific information documented in the SSA report, we have not
only analyzed individual effects on the species, 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 species. Our assessment of the
current and future conditions encompasses and incorporates the threats
individually and cumulatively. Our current and future condition
assessment is iterative because it accumulates and evaluates the
effects of all the factors that may be influencing the species,
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 species, our assessment
integrates the cumulative effects of the factors and replaces a
standalone cumulative effects analysis.
Summary of Comments and Recommendations
In the proposed rule published on December 27, 2017 (82 FR 61230),
we requested that all interested parties submit written comments on the
proposal by February 26, 2018. We also contacted appropriate Federal
and State agencies, scientific experts and organizations, and other
interested parties and invited them to comment on the proposal. We
published a press release notifying the general public of the
opportunity to comment on our proposed rule. We did not receive any
requests for a public hearing. We reviewed all comments we received
from peer reviewers and the public for substantive issues and new
information. All substantive information provided during the comment
period has either been incorporated directly into this final
determination or is addressed below.
Peer Reviewer Comments
As discussed in Supporting Documents above, we received responses
from two peer reviewers. We reviewed all comments we received from the
peer reviewers for substantive issues and new information regarding the
information contained in the SSA report. The peer reviewers generally
concurred with our methods and conclusions, and provided additional
information, clarifications, and suggestions to improve the final SSA
report. Peer reviewer comments are addressed in the following summary
and were incorporated into the final SSA report as appropriate.
One peer reviewer provided additional information on ongoing and
new conservation efforts on the Yangtze River. These efforts include
lengthening fishing bans within the species' range and the commencement
of restocking efforts on reaches below Gezhouba Dam. We have
incorporated the new information into this rule.
We received 24 public comments on the proposed rule to list the
Yangtze surgeon as an endangered species under the Act. The majority of
the comments reviewed were nonsubstantive as they were unrelated to the
rule to list the Yangtze sturgeon. The following discussion summarizes
issues and substantive information from public comments and provides
our responses.
Comment (1): One commenter questioned the effectiveness of the
listing of foreign species and stated that the listing of foreign
species can have a negative impact on conservation efforts for foreign
species undertaken by private entities.
Our Response: The decision to list a species under the Act is based
on whether the species meets the definition of an endangered species or
a threatened species, as defined under section 3 of the Act, and is
made solely on the basis of the best scientific and commercial data
available. Additionally, we were petitioned to list this species and
are required to respond to the petition. Conservation measures provided
to species listed as endangered or threatened under the Act include
recognition, requirements for Federal protection, and prohibitions
against certain practices. Recognition through listing results in
public awareness, and may encourage and result in conservation actions
by foreign governments, Federal and State governments, private agencies
and interest groups, and individuals. Listing under the Act can help
ensure that the United States and its citizens do not contribute to the
further decline of the species. For additional information see
Available Conservation Measures, below.
Comment (2): One commenter stated that the species should not be
listed until more sources are included.
Our Response: The Service is required by the Act to make
determinations solely on the basis of the best scientific and
commercial data available. We based this final rule on all the
information we received following the publication of the proposed rule,
as well as all of the information we found during our own research. At
this time, we consider the information we
[[Page 21959]]
compiled to be the best available information. The information we
received during the proposed rule's comment period has been
incorporated into this final rule, as appropriate.
Determination of Yangtze Sturgeon 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 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 a species meets the definition of
``endangered species'' or ``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.
Yangtze Sturgeon Status Throughout All of Its Range
We have carefully assessed the best scientific and commercial
information available on the Yangtze sturgeon. While we do not know the
exact population size of the Yangtze sturgeon, the species was
historically abundant enough to be commercially viable up to the 1970s,
after which it experienced a significant decline (Kynard et al. 2003,
p. 27). Loss of individuals due to overharvesting by fishermen on the
Yangtze (Factor B) is the main factor that contributed to the
historical decline of the species. Subsequent construction of dams on
the Yangtze prevented the migration in the middle Yangtze and lower
Jinsha, which has prevented recovery of the species in these areas
(Miao et al. 2015, p. 2351; Wu et al. 2014, p. 2; Dudgeon 2010, p. 128;
Fang et al. 2006, p. 375; Zhuang et al. 1997, p. 261). Additionally,
dams affect the quality of the species' habitat through changes in
discharge, temperature, and sedimentation rate (Zhang G. et al. 2012,
p. 445; Du et al. 2011, p. 262; Chen Z. et al. 2001, p. 90). In
addition to dams, the species' habitat is also adversely affected by
riverbed modification to accommodate increasing boat traffic. The
combined effects of dams and riverbed modification on the Yangtze River
have resulted in the loss and reduction in quality of remaining habitat
for the species (Factor A).
Despite conservation efforts undertaken by local and national
authorities, such as fishing bans and restocking, current efforts do
not appear to be successful in conserving the species. No natural
reproduction has been documented in the wild since 2008 (Wu et al.
2014, p. 1). Additionally, restocked juvenile sturgeon experience very
high mortality rates due to a high bycatch rate and an inability to
survive in wild conditions (Du et al. 2014, p. 1; Wu et al. 2014, p.
4).
Industrial pollution, and hybridization with displaced native and
nonnative sturgeon species, are also acting on the species (Factor E).
Although we do not have information on the impact of industrial
pollution on the species in the wild, there are high concentrations of
TPT and EDC in the Yangtze River, and studies in a laboratory
environment found that these pollutants can reduce the reproductive
success rate of adult sturgeon (Hu et al. 2009, p. 9342; An and Hu
2006, pp. 379-380). While we do not have data on the hybridization of
Yangtze sturgeon with other species, surveys conducted in the lower
Yangtze River found that 69.9 percent of sturgeon species caught were
hybrids (Li R. et al. 2009, p. 636). The results suggest that
industrial pollution and hybridization, in tandem with other factors,
are adversely affecting the species.
Therefore, for the following reasons, we conclude that this species
has been and continues to be significantly reduced to the extent that
the viability of the Yangtze sturgeon is significantly compromised:
(1) The species is limited to a single geographic population in the
upper Yangtze River main stem and its tributaries. There is also some
evidence of a small remnant population in the middle Yangtze.
(2) Loss of habitat and connectivity between the spawning and
feeding reaches due to dam construction and operation is having a
significant adverse effect on the species, which appears to have low to
no reproduction in the wild.
(3) The cumulative effects of habitat modification and loss due to
dams and riverbed projects, bycatch, industrial pollution, and
hybridization are adversely affecting the species.
(4) Current restocking and management efforts are inadequate to
maintain the species' presence in the wild.
(5) Stochastic events, such as industrial spills or drought, can
reduce the survival rate of the species.
We find that the Yangtze sturgeon is presently in danger of
extinction throughout its range based on the severity and immediacy of
threats currently adversely affecting the species. The populations and
distributions of the species have been significantly reduced to the
point where there is low to no current reproduction in the wild, which
is indicative of a very high risk of extinction, and the remaining
habitat and populations are at risk due to a variety of factors acting
alone and in combination to reduce the overall viability of the
species.
After evaluating threats to the species and assessing the
cumulative effect of the threats under the section 4(a)(1) factors, we
find the following factors to be threats to this species (i.e., factors
contributing to the risk of extinction of this species): Loss and
modification of habitat due to dams and riverbed expansion (Factor A);
bycatch (Factor E); and cumulative effects (Factor E) of these and
other threats, including industrial pollution and hybridization.
Furthermore, current legal and management efforts over these practices
are inadequate to conserve the species (Factor D). Thus, after
assessing the best available information, we conclude that Yangtze
sturgeon is in danger of extinction throughout all of its range. We
find that a threatened species status is not appropriate for this
species because of its restricted range, limited distribution, and
vulnerability to extinction, and because the threats are ongoing
throughout its range at a level that places this species in danger of
extinction now.
Yangtze Sturgeon 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 Yangtze sturgeon is in danger of
extinction throughout all of its range, and accordingly, did not
undertake an analysis of any significant portions of its range. Because
we have determined that the Yangtze sturgeon warrants listing as
endangered throughout all of its range, our determination is consistent
with the decision in Center for Biological Diversity v. Everson, 2020
WL 437289 (D.D.C. Jan. 28, 2020), in which the court vacated the aspect
of the Final Policy on Interpretation of the Phrase ``Significant
Portion of Its Range'' in the
[[Page 21960]]
Endangered Species Act's Definitions of ``Endangered Species'' and
``Threatened Species'' (79 FR 37578; July 1, 2014) that provided the
Services do not undertake an analysis of significant portions of a
species' range if the species warrants listing as threatened throughout
all of its range.
Determination of Status
Our review of the best available scientific and commercial
information indicates that the Yangtze sturgeon meets the definition of
an endangered species. Therefore, we are listing the Yangtze sturgeon
as an endangered species 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, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness, and
encourages and results in conservation actions by Federal, State,
Tribal, and local agencies, foreign governments, 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 and the
prohibitions against certain activities are discussed, in part, below.
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.
An ``action'' that is subject to the consultation provisions of
section 7(a)(2) is defined in our implementing regulations at 50 CFR
402.02 as all activities or programs of any kind authorized, funded, or
carried out, in whole or in part, by Federal agencies in the United
States or upon the high seas. With respect to this species, there are
no ``actions'' known to require consultation under section 7(a)(2) of
the Act. Given the regulatory definition of ``action,'' which clarifies
that it applies to activities or programs ``in the United States or
upon the high seas,'' the Yangtze sturgeon is unlikely to be the
subject of section 7 consultations, because the entire life cycle of
the species occurs in freshwater and nearshore marine areas outside of
the United States unlikely to be affected by U.S. Federal actions.
Additionally, no critical habitat will be designated for this species
because, under 50 CFR 424.12(g), we will not designate critical habitat
within foreign countries or in other areas outside of the jurisdiction
of the United States.
Section 8(a) of the Act (16 U.S.C. 1537(a)) authorizes the
provision of limited financial assistance for the development and
management of programs that the Secretary of the Interior determines to
be necessary or useful for the conservation of endangered or threatened
species in foreign countries. Sections 8(b) and 8(c) of the Act (16
U.S.C. 1537(b) and (c)) authorize the Secretary to encourage
conservation programs for foreign listed species, and to provide
assistance for such programs, in the form of personnel and the training
of personnel.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all 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 import; export; deliver, receive,
carry, transport, or ship in interstate or foreign commerce, by any
means whatsoever and in the course of commercial activity; or sell or
offer for sale in interstate or foreign commerce any species listed as
an endangered species. In addition, it is unlawful 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. It is also illegal to possess, sell,
deliver, carry, transport, or ship, by any means whatsoever any such
wildlife that has been taken illegally. Certain exceptions apply to
employees of the Service, the National Marine Fisheries Service (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 for endangered wildlife are codified at 50 CFR 17.22,
and general Service permitting regulations are codified at 50 CFR part
13. With regard to endangered wildlife, a permit may be issued for the
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 Service may also register persons
subject to the jurisdiction of the United States through its captive-
bred-wildlife (CBW) program if certain established requirements are met
under the CBW regulations (50 CFR 17.21(g)). Through a CBW
registration, the Service may allow a registrant to conduct certain
otherwise prohibited activities under certain circumstances to enhance
the propagation or survival of the affected species: Take; export or
re-import; deliver, receive, carry, transport or ship in interstate or
foreign commerce, in the course of a commercial activity; or sell or
offer for sale in interstate or foreign commerce. A CBW registration
may authorize interstate purchase and sale only between entities that
both hold a registration for the taxon concerned. The CBW program is
available for species having a natural geographic distribution not
including any part of the United States and other species that the
Director has determined to be eligible by regulation. The individual
specimens must have been born in captivity in the United States. There
are also certain statutory 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 final listing
on proposed and ongoing activities within the range of a listed
species. 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 Yangtze sturgeon in its native range; and
(2) Trade in the Yangtze sturgeon and its products that is both
outside the United States and conducted by persons
[[Page 21961]]
not subject to U.S. jurisdiction (although this activity would still be
subject to CITES requirements).
Separate from its final listing as an endangered species, as a
CITES-listed species, all international trade of Yangtze sturgeon by
persons subject to the jurisdiction of the United States must also
comply with CITES requirements pursuant to section 9(c) and 9(g) of the
Act and to 50 CFR part 23. Applicable wildlife import/export
requirements established under section 9(d) through 9(f) of the Act,
the Lacey Act Amendments of 1981 (16 U.S.C. 3371 et seq.), and 50 CFR
part 14 must also be met for Yangtze sturgeon imports and exports.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Branch of
Delisting and Foreign Species (see FOR FURTHER INFORMATION CONTACT).
Required Determinations
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (42 U.S.C. 4321 et seq.), need not be prepared
in connection with listing a species as an endangered or threatened
species under the Endangered Species Act. We published a notice
outlining our reasons for this determination in the Federal Register on
October 25, 1983 (48 FR 49244).
References Cited
A complete list of references cited in this rulemaking is available
on the internet at http://www.regulations.gov and upon request from the
Branch of Delisting and Foreign Species, Ecological Services (see FOR
FURTHER INFORMATION CONTACT).
Authors
The primary authors of this final rule are the staff members of the
Branch of Delisting and Foreign Species, Ecological Services, Falls
Church, VA.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we 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 ``Sturgeon, Yangtze'' to
the List of Endangered and Threatened Wildlife in alphabetical order
under FISHES to read as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
----------------------------------------------------------------------------------------------------------------
Listing citations and
Common name Scientific name Where listed Status applicable rules
----------------------------------------------------------------------------------------------------------------
* * * * * * *
----------------------------------------------------------------------------------------------------------------
FISHES
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Sturgeon, Yangtze.............. Acipenser Wherever found.... E.............. 86 FR [insert Federal
dabryanus. Register page where
the document begins],
4/26/2021.
* * * * * * *
----------------------------------------------------------------------------------------------------------------
Martha Williams,
Principal Deputy Director, Exercising the Delegated Authority of the
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2021-08466 Filed 4-23-21; 8:45 am]
BILLING CODE 4333-15-P