[Federal Register Volume 82, Number 121 (Monday, June 26, 2017)]
[Proposed Rules]
[Pages 28802-28813]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-13250]



National Oceanic and Atmospheric Administration

50 CFR Part 224

[Docket No. 160413329-7546-02]
RIN 0648-XE571

Endangered and Threatened Wildlife and Plants; Proposed 
Endangered Listing Determination for the Taiwanese Humpback Dolphin 
Under the Endangered Species Act (ESA)

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

ACTION: Proposed rule; request for comments.


SUMMARY: We, NMFS, have completed a comprehensive status review under 
the Endangered Species Act (ESA) for the Taiwanese humpack dolphin 
(Sousa chinensis taiwanensis) in response to a petition from Animal 
Welfare Institute, Center for Biological Diversity, and WildEarth 
Guardians to list the species. Based on the best scientific and 
commercial information available, including the draft status review 
report (Whittaker and Young, 2017), and taking into consideration 
insufficient efforts being made to protect the species, we have 
determined that the Taiwanese humpback dolphin has a high risk of 
extinction throughout its range and warrants listing as an endangered 

DATES: Comments on this proposed rule must be received by August 25, 
2017. Public hearing requests must be requested by August 10, 2017.

ADDRESSES: You may submit comments on this document, identified by 
NOAA-NMFS-2016-0041, by either of the following methods:
     Electronic Submissions: Submit all electronic comments via 
the Federal eRulemaking Portal. Go to www.regulations.gov/#!docketDetail;D= NOAA-NMFS-2016-0041, click the ``Comment Now!'' icon, 
complete the required fields, and enter or attach your comments.
     Mail: Submit written comments to Chelsey Young, NMFS 
Office of Protected Resources (F/PR3), 1315 East West Highway, Silver 
Spring, MD 20910, USA. Attention: Taiwanese humpback dolphin proposed 
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address, etc.), confidential business 
information, or otherwise sensitive information submitted voluntarily 
by the sender will be publicly accessible. NMFS will accept anonymous 
comments (enter ``N/A'' in the required fields if you wish to remain 
    You can find the petition, status review report, Federal Register 
notices, and the list of references electronically on our Web site at 
http://www.fisheries.noaa.gov/pr/species/mammals/dolphins/indo-pacific-humpback-dolphin.html. You may also receive a copy by submitting a 
request to the Office of Protected Resources, NMFS, 1315 East-West 
Highway, Silver Spring, MD 20910, Attention: Taiwanese humpback dolphin 
proposed rule.

Protected Resources, (301) 427-8403.



    On March 9, 2016, we received a petition from the Animal Welfare 
Institute, Center for Biological Diversity and WildEarth Guardians to 
list the Taiwanese humpback dolphin (S. chinensis taiwanensis) as 
threatened or endangered under the ESA throughout its range. This 
population of humpback dolphin was previously considered for ESA 
listing as the Eastern Taiwan Strait distinct population segment (DPS) 
of the Indo-Pacific humpback dolphin (Sousa chinensis); however, we 
determined that the population was not eligible for listing as a DPS in 
our 12-month finding (79 FR 74954; December 16, 2014) because it did 
not meet all the necessary criteria under the DPS Policy (61 FR 4722; 
February 7, 1996). Specifically, we determined that while the Eastern 
Taiwan Strait population was ``discrete,'' the population did not 
qualify as ``significant.'' The second petition asserted that new 
scientific and taxonomic information demonstrates that the Taiwanese 
humpback dolphin is actually a subspecies, and stated that NMFS must 
reconsider the subspecies for ESA listing. On May 12, 2016, we 
published a positive 90-day finding for the Taiwanese humpback dolphin 
(81 FR 29515), announcing that the petition presented substantial 
scientific or commercial information indicating the petitioned action 
of listing the subspecies may be warranted, and explaining the basis 
for those findings. We also announced the initiation of a status review 
of the subspecies, as required by section 4(b)(3)(A) of the ESA, and 
requested information to inform the agency's decision on whether the 
species warranted listing as endangered or threatened under the ESA.

Listing Species Under the Endangered Species Act

    We are responsible for determining whether species are threatened 
or endangered under the ESA (16 U.S.C. 1531 et seq.). To make this 
determination, we first consider whether a group of organisms

[[Page 28803]]

constitutes a ``species'' under section 3 of the ESA, then whether the 
status of the species qualifies it for listing as either threatened or 
endangered. Section 3 of the ESA defines species to include ``any 
subspecies of fish or wildlife or plants, and any distinct population 
segment of any species of vertebrate fish or wildlife which interbreeds 
when mature.'' On February 7, 1996, NMFS and the U.S. Fish and Wildlife 
Service (USFWS; together, the Services) adopted a policy describing 
what constitutes a DPS of a taxonomic species (61 FR 4722). The joint 
DPS policy identified two elements that must be considered when 
identifying a DPS: (1) The discreteness of the population segment in 
relation to the remainder of the species (or subspecies) to which it 
belongs; and (2) the significance of the population segment to the 
remainder of the species (or subspecies) to which it belongs.
    Section 3 of the ESA defines an endangered species as ``any species 
which is in danger of extinction throughout all or a significant 
portion of its range'' and a threatened species as one ``which is 
likely to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range.'' Thus, in the 
context of the ESA, the Services interpret an ``endangered species'' to 
be one that is presently at risk of extinction. A ``threatened 
species,'' on the other hand, is not currently at risk of extinction, 
but is likely to become so in the foreseeable future. In other words, a 
key statutory difference between a threatened and endangered species is 
the timing of when a species may be in danger of extinction, either now 
(endangered) or in the foreseeable future (threatened). The statute 
also requires us to determine whether any species is endangered or 
threatened as a result of any of the following five factors: the 
present or threatened destruction, modification, or curtailment of its 
habitat or range; overutilization for commercial, recreational, 
scientific, or educational purposes; disease or predation; the 
inadequacy of existing regulatory mechanisms; or other natural or 
manmade factors affecting its continued existence (ESA, section 
4(a)(1)(A)-(E)). Section 4(b)(1)(A) of the ESA requires us to make 
listing determinations based solely on the best scientific and 
commercial data available after conducting a review of the status of 
the species and after taking into account efforts being made by any 
State or foreign nation or political subdivision thereof to protect the 

Status Review

    The status review for the Taiwanese humpback dolphin was completed 
by NMFS staff from the Office of Protected Resources. To complete the 
status review, we compiled the best available data and information on 
the subspecies' biology, ecology, life history, threats, and 
conservation status by examining the petition and cited references, and 
by conducting a comprehensive literature search and review. We also 
considered information submitted to us in response to our petition 
finding. The draft status review report was subjected to independent 
peer review as required by the Office of Management and Budget Final 
Information Quality Bulletin for Peer Review (M-05-03; December 16, 
2004). The draft status review report was peer reviewed by three 
independent specialists selected from the academic and scientific 
community, with expertise in cetacean biology, conservation and 
management, and specific knowledge of the Taiwanese humpback dolphin. 
The peer reviewers were asked to evaluate the adequacy, 
appropriateness, and application of data used in the draft status 
review report as well as the findings made in the ``Assessment of 
Extinction Risk'' section of the report. All peer reviewer comments 
were addressed prior to finalizing the draft status review report.
    We subsequently reviewed the status review report, and its cited 
references, and we believe the status review report, upon which this 
proposed rule is based, provides the best available scientific and 
commercial information on the Taiwanese humpback dolphin. Much of the 
information discussed below on the dolphin's biology, distribution, 
abundance, threats, and extinction risk is attributable to the status 
review report. However, we have independently applied the statutory 
provisions of the ESA, including evaluation of the factors set forth in 
section 4(a)(1)(A)-(E), our regulations regarding listing 
determinations, and our DPS policy in making the 12-month finding 
determination. The draft status review report (cited as Whittaker and 
Young 2017) is available on our Web site (see ADDRESSES section). In 
the sections below, we provide information from the report regarding 
threats to and the status of the Taiwanese humpback dolphin.

Description, Life History, and Ecology of the Petitioned Species

Species Description

    The Taiwanese humpback dolphin (Sousa chinensis taiwanensis) is a 
recently recognized subspecies of the Indo-Pacific humpback dolphin 
(Sousa chinensis; Wang et al., 2015). Sousa chinensis is a broadly 
distributed species within the family Delphinidae and order 
Cetartiodactyla, whereas the Taiwanese subspecies occurs in a 
restricted area of shallow waters off the western coast of Taiwan. The 
subspecies of Sousa chinensis occurring in the Eastern Taiwan Strait--
Sousa chinensis taiwanensis (herein referred to as the Taiwanese 
humpback dolphin) was first described in 2002 during an exploratory 
survey of coastal waters off western Taiwan (Wang et al., 2004b). Prior 
to coastal surveys, there were few records mentioning the species in 
this region, save two strandings, a few photographs, and anecdotal 
reports (Wang, 2004). Since the first survey in 2002, researchers have 
confirmed their year-round presence in the Eastern Taiwan Strait (Wang 
and Yang, 2011).
    In terms of distinctive physical characteristics, the Indo-Pacific 
humpback dolphin is generally easy to distinguish from other dolphin 
species in its range. In general, the Indo-Pacific humpback dolphin is 
medium-sized, up to 2.8 m in length, and weighs 250-280 kg (Ross et 
al., 1994). It is characterized by a robust body, long distinct beak, 
short dorsal fin atop a wide dorsal hump, and round-tipped broad 
flippers and flukes (Jefferson and Karczmarski, 2001). The base of the 
fin measures 5-10 percent of the body length, and slopes gradually into 
the surface of the body; this differs from individuals in the western 
portion of the range, which have a larger hump that comprises about 30 
percent of body width, and forms the base of an even smaller dorsal fin 
(Ross et al., 1994).
    When young, humpback dolphins appear dark grey with no or few 
light-colored spots, and transform to mostly white (appearing pinkish) 
as dark spots decrease with age. However, the developmental 
transformation of pigment differs between Taiwanese and Chinese 
humpback dolphin populations, and the spotting intensity on the dorsal 
fin of the Taiwanese population is significantly greater than that in 
other nearby populations in the Pearl River estuary (PRE) or Jiulong 
River estuaries of the Chinese mainland (Wang et al., 2008). In fact, 
Wang et al. (2008) concluded that these differences in pigmentation can 
be used to reliably distinguish the Taiwanese humpback dolphin from 
other nearby populations, and Wang et al. (2015) further confirmed that 
Taiwanese humpback dolphins were ``clearly diagnosable from those of 
mainland China under the most commonly accepted 75 percent rule for 
subspecies delimitation, with 94

[[Page 28804]]

percent of one group being separable from 99 percent of the other.'' 
Based on this information, as well as additional evidence of 
geographical isolation and behavioral differences, the authors 
concluded that the Taiwanese humpback dolphin qualifies as a 
subspecies, and revised the taxonomy of Sousa chinensis to include two 
subspecies: The Taiwanese humpback dolphin (S. chinensis taiwanensis) 
and the Chinese humpback dolphin (S. chinensis chinensis) (Wang et al., 
2015). Because of the new information as presented in Wang et al. 
(2015), the Taxonomy Committee of the Society for Marine Mammalogy 
officially revised its list of marine mammal taxonomy to recognize the 
Taiwanese humpback dolphin as a subspecies (Committee on Taxonomy, 

Range, Distribution and Habitat Use

    The Taiwanese humpback dolphin has a very restricted range, 
residing in the shallow coastal waters of central western Taiwan 
throughout the year (Wang et al., 2007a; Wang et al., 2016), with no 
evidence of seasonal movements (Wang and Yang, 2011; Wang et al., 
2016). Although the total distribution of the dolphin covers 
approximately 750 km\2\, the subspecies' core distribution encompasses 
approximately 512 km\2\ of coastal waters, from estuarine waters of the 
Houlong and Jhonggang rivers in the north, to waters of Waishanding 
Jhou to the south (Wang et al., 2016). This equates to a linear 
distance of approximately 170 km. However, the main concentration of 
the population occurs between the Tongsaio River estuary and Taisi, 
which encompasses the estuaries of the Dadu and Jhushuei rivers, the 
two largest river systems in western Taiwan (Wang et al., 2007a). 
Typically, the Taiwanese humpback dolphin is found within 3 km from the 
shore (Dares et al., 2014; Wang et al., 2016).
    Rarely, individuals have been sighted and strandings have occurred 
in near-shore habitat to the north and south of its current confirmed 
habitat; some of these incidents are viewed as evidence that the 
historical range of the population extended farther than its current 
range (Dungan et al., 2011). However, two specific anomalous sightings 
are considered incidences of vagrancy, involving sick or dying animals. 
All but two sightings have occurred in shallow water, less than 20 m, 
and as shallow as 1.5 m. The only two sightings that occurred in water 
deeper than 20 m occurred in habitat where dredging had occurred (Wang 
et al., 2007b). In fact, the Taiwanese humpback dolphin is thought to 
be geographically isolated from mainland Chinese populations, with 
water depth being the primary factor dictating their separation. The 
Taiwan Strait is 140-200 km wide, and consists of large expanses of 
water 50-70 m deep (the Wuchi and Kuanyin depressions). Despite 
extensive surveys, Taiwanese humpback dolphins have never been observed 
in water deeper than 30 m. As noted previously, the majority of 
sightings have been made in waters less than 20 m deep, but individuals 
have been known to cross deep (>30 m) shipping channels in inshore 
waters that have been dredged (Dares et al., 2014). Thus, deep water is 
thought to be the specific barrier limiting exchange with Chinese 
mainland populations (Jefferson and Karczmarski, 2001). Sousa species 
in general have limited mobility, and restriction to shallow, near-
shore estuarine habitats is a significant barrier to movement 
(Karczmarski et al., 1997; Hung and Jefferson, 2004). Thus, confirmed 
present habitat constitutes a narrow region along the coast, which is 
affected by high human population density and extensive industrial 
development (Ross et al., 2010; Karczmarski et al., 2016; Wang et al., 
    Overall, water depth and the subspecies' need for access to 
inshore, estuarine waters, as well as the estuarine distribution of 
prey species, are likely the main factors underpinning habitat use and 
distribution of Taiwanese humpback dolphins (Dares et al., 2014; Wang 
et al., 2016). The input of freshwater to the habitat is thought to be 
important in sustaining estuarine productivity, and thus supporting the 
availability of prey for the dolphin (Jefferson, 2000). Across the 
Taiwanese humpback dolphin habitat, bottom substrate consists of soft 
sloping muddy sediment with elevated nutrient inputs primarily 
influenced by river deposition (Sheehy, 2010). These nutrient inputs 
support high primary production, which fuels upper trophic levels 
contributing to the dolphin's source of food. Thus, the characteristics 
defining distribution and habitat use of the Taiwanese humpback dolphin 
are similar to those of other humpback dolphin populations (Dares et 
al., 2014).

Diet and Feeding

    Information on this Taiwanese humpback dolphin's foraging behavior 
and specific diet is limited, but the dolphins seem to have an 
opportunistic diet comprised primarily of estuarine fish (e.g., 
sciaenids, mugilids, congrids, clupeoids), and either do not or rarely 
feed on cephalopods and crustaceans (Wang et al., 2016). While the 
subspecies does not seem to show the same attraction to fishing vessels 
as the nearby Pearl River estuary (PRE) population, some evidence 
(e.g., net entanglements and observations of individuals feeding around 
and behind set gillnets and trawl nets, respectively) indicate that 
Taiwanese humpback dolphins may opportunistically feed in proximity to 
deployed fishing gear (Slooten et al., 2013; Wang et al., 2016). As is 
common to the species as a whole, the Taiwanese subspecies uses 
echolocation and passive listening to find its prey.

Reproduction and Growth

    Little is known about the life history and reproduction of the 
Taiwanese humpback dolphin, and estimating life history parameters for 
the subspecies has proven difficult due to the lack of carcasses 
available for study (Wang et al., 2016). A recent analysis of life 
history patterns for individuals in the PRE population may offer an 
appropriate proxy for understanding life history of the Taiwanese 
humpback dolphin, as the PRE population similarly inhabits estuarine 
and freshwater-influenced environments affected by comparable threats 
of pollution, as well as industrial development and fishing activity 
(Jefferson et al., 2012). Additionally, life history traits of the PRE 
population are similar to the South African population, suggesting that 
some general assumptions of productivity can be gathered, even on the 
genus-level (Jefferson and Karczmarski, 2001; Jefferson et al., 2012). 
However, it should be noted that environmental factors (e.g., food 
availability, habitat status) may affect important rates of 
reproduction and generation time in different populations, and thus 
comparisons should be regarded with some caution.
    Maximum longevity for PRE and South African populations is 39 and 
40 years, respectively (Jefferson et al., 2012; Jefferson and 
Karcsmarski, 2001); therefore, we assume that the Taiwanese humpback 
dolphin experiences a similar life expectancy. Likewise, we also expect 
the Taiwanese humpback dolphin to have an age at sexual maturity for 
females similar to that for the PRE and South African populations (12-
14 years). In general, it has been assumed that the Taiwanese 
subspecies experiences long calving intervals, between 3 and 5 years 
(Jefferson et al., 2012). A recent study on the reproductive parameters 
of the Taiwanese humpback dolphin confirmed this assumption, and

[[Page 28805]]

estimated the mean calving interval (defined as the period between the 
estimated birth months of two successive calves) to be 3.26 years 
 SD 1.23 years (Chang et al., 2016). However, it is 
important to note that the results of this study are based on only 4 
years of data; therefore, females with potentially longer calving 
intervals would not have been observed or recorded. Taiwanese humpback 
dolphin births occur throughout the year, but decrease in late summer 
and through mid-winter, with 69 percent of the estimated months of 
birth occurring in spring and summer (Chang et al., 2016). In terms of 
survival, between 1 and 3 calves survive annually to the age of 1-year 
(mean = 2.75), with survival of calves declining across the initial 3 
years of life, from 0.778 (at 6 months) to 0.667 (at 1 year), and from 
0.573 to 0.563 at ages of 2 and 3 years, respectively (Chang et al., 
2016). Chang et al. (2016) hypothesized that the relatively low calf 
survival observed in the Taiwanese humpback dolphin population is more 
likely due to anthropogenic factors (e.g., fisheries interactions and 
habitat destruction) than natural causes. Overall, the Taiwanese 
humpback dolphin is likely long-lived, slow to mature, and has low 
recruitment rates and long calving intervals. These life history 
parameters indicate slow population growth, which contributes to a 
limited capacity for the subspecies to exhibit resilience to 
anthropogenic stressors (Chang et al., 2016).

Population Structure

    No genetic data exist for the Taiwanese humpback dolphin; 
therefore, the genetic connectivity within the population cannot be 
directly assessed. However, in such a small population, social behavior 
and habitat connectivity may provide clues to the connectivity of the 
population as a whole. In general, humpback dolphin (Sousa spp.) 
populations are known for having generally weak, fluctuating 
associations in `fission-fusion' societies (i.e., social groups that 
change in size and composition as time passes and individuals move 
throughout the environment; Dungan, 2016; Wang et al., 2016; Dungan, 
2012; Jefferson, 2000). However, a recent study of association patterns 
in Taiwanese humpback dolphins found that the Taiwanese subspecies 
exhibits stronger, persistent relationships among individuals, 
particularly among cohorts of mother-calf pairs (Dungan et al., 2016), 
with a unique level of stability in the population compared to other 
humpback dolphin populations (Wang et al., 2016). This high social 
cohesion is most likely related to cooperative calf rearing, wherein 
raising offspring with the assistance of peers or kin can increase 
offspring survivorship and thereby increase the fitness of the 
population (Dungan et al., 2016). This behavior is thought to be an 
adaptive response to the dolphin's degraded, geographically restricted 
environment (which makes it difficult for mothers to support offspring 
on their own), and to their small population size (which has likely 
increased the relatedness of individuals) (Dungan, 2011). Calves and 
their inferred mothers seem to have central positions in the social 
network, which suggests that mother-calf pairs may be the key 
underlying factor for overall network structure (Dungan et al., 2016). 
Given the subspecies' unique cohesive social network, persisting 
associations, and the reliance on cooperative rearing behaviors of 
mother-calf groups for reproductive fitness and survival, disruption of 
these social patterns could have significant ramifications regarding 
the dolphin's ability to reproduce as well as calf survivorship (Dungan 
et al., 2016), which is already reportedly low (Chang et al., 2016).

Population Abundance and Trends

    There are only two formal estimates of abundance for the Taiwanese 
humpback dolphin. The first study estimated a population size of 99 
individuals (coefficient of variation (CV) = 52 percent, 95 percent 
confidence interval (CI) = 37-266) based on surveys that used line 
transects to count animals from 2002 to 2004 (Wang et al., 2007b). A 
new estimate of population abundance with data collected between 2007 
and 2010 using mark-recapture methods of photo identification allowed 
for higher-precision measurements (Wang et al., 2012). Yearly 
population estimates from this study ranged from 54 to 74 individuals 
in 2009 and 2010, respectively (CV varied from 4 percent to 13 
percent); these estimates were 25 to 45 percent lower than those from 
2002-2004 (Wang et al., 2012). Carrying capacity for the Taiwanese 
humpback dolphin has been estimated at 250 individuals (which was set 
higher than the highest point estimate abundance from Wang et al. 
(2012)), as extrapolated from the mean density estimate for the 
population (Ara[uacute]jo et al., 2014); this estimate suggests that 
the population abundance has been reduced from historical levels.
    An analysis of potential biological removal (PBR), which, under the 
Marine Mammal Protection Act (MMPA), is a measure of the maximum number 
of individuals that can be removed from a population without depleting 
it (Wade, 1998), was conducted to assess the sustainability and 
stability of the Taiwanese humpback dolphin in the face of present 
threats, and their projected future trends (Slooten et al., 2013). 
Using the most current abundance estimate, and assuming that the 
Taiwanese humpback dolphin population is a closed and discrete 
population based on information provided in Wang et al. (2012), Slooten 
et al. (2013) assessed the number of individuals in the population that 
may be lost due to occurrences other than natural mortality and still 
allow for population stability and recovery. The authors calculated 
that a sustainable population could withstand no more than one human-
caused dolphin death every 7 to 7.6 years. Thus, even a single human-
caused mortality per year would exceed the PBR by a factor of seven 
(Slooten et al., 2013). Their assessment took into account all non-
natural mortality including fishing, pollution, vessel strikes, habitat 
destruction, and other human activities, and determined that current 
removal of individuals from the population exceeds the PBR necessary 
for population stability which would prevent decline, support natural 
population growth, and allow for improved status (Slooten et al., 
2013). Given the population's mortality rate of 1.5 percent (Wang et 
al., 2012), current rates of population decline are likely 
    An extremely low population size estimate (fewer than 100 
individuals) is well supported by current available data, and recent 
population viability analyses (PVAs) suggest that the population is 
declining due to the synergistic effects of habitat degradation and 
detrimental fishing interactions (Ara[uacute]jo et al., 2014; Huang et 
al., 2014). Ara[uacute]jo et al. (2014) modeled population trajectory 
over 100 years using demographic factors alongside different levels of 
mortality attributed to bycatch, and loss of carrying capacity due to 
habitat loss/degradation. The model predicted a high probability of 
ongoing population decline under all scenarios. For instance, 
population size was predicted to be smaller than the initial size in 
more than 76 percent of all model runs, with the final population size 
predicted to be <1 individual (i.e., extinction) in 66 percent of all 
model runs (Ara[uacute]jo et al., 2014). Another PVA was performed by 
using an individual-based model to account for parametric uncertainty 
and demographic stochasticity (Huang et al., 2014). Although this model 
showed wide

[[Page 28806]]

variation in population growth estimates (ranging from a significant 
decline of -0.113 to a moderate increase of 0.0317), the end result for 
the subspecies was still an overall decline, with 69.4 percent of 
simulations predicting a population decline of greater than 25 percent 
within one generation (i.e., 22 years) and the majority of simulations 
(54 percent) predicting local extinction within 100 years (Huang et 
al., 2014).
    Overall, although the two PVA studies differed in their findings 
with regard to the relative importance of bycatch and habitat loss 
threats, both assessments concluded that the subspecies is in serious 
danger of going extinct (Wang et al., 2016). Ultimately, strong 
evidence suggests that the Taiwanese humpback dolphin population size 
is critically small, and rates of decline are high and likely 
unsustainable. Further, it is clear that loss of only a single 
individual within the population per year would substantially reduce 
population growth rate and is thus unsustainable (Dungan et al., 2011, 
Slooten et al., 2013)

Assessment of Extinction Risk

    The ESA (section 3) defines an endangered species as ``any species 
which is in danger of extinction throughout all or a significant 
portion of its range.'' A threatened species is defined as ``any 
species which is likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range.'' Neither we nor the USFWS have developed formal policy guidance 
about how to interpret the definitions of threatened and endangered 
with respect to what it means to be ``in danger of extinction.'' We 
consider the best available information and apply professional judgment 
in evaluating the level of risk faced by a species in deciding whether 
the species is threatened or endangered. We evaluate demographic risks, 
such as low abundance and productivity, and threats to the species, 
including those related to the factors specified in ESA section 
    For purposes of assessing extinction risk for the Taiwanese 
humpback dolphin, we reviewed the best available information on the 
species and evaluated the overall risk of extinction facing the 
Taiwanese humpback dolphin, now and in the foreseeable future. The term 
``foreseeable future'' was discussed qualitatively in the status review 
report and defined as the timeframe over which threats could be 
projected with a reasonable amount of confidence. After considering the 
life history of the Taiwanese humpback dolphin, availability of data, 
and types of threats, we determined that a reasonable foreseeable 
future should extend out several decades (>50 years). The foreseeable 
future timeframe is also a function of the reliability of available 
data regarding the identified threats and extends only as far as the 
data allow for making reasonable predictions about the species' 
response to those threats. Given the Taiwanese humpback dolphin's life 
history traits, including longevity estimated to be upwards of 40 
years, estimated maturity range of 12-14 years, low reproductive rates 
and long calving intervals of >3 years, it would likely take more than 
a few decades (i.e., multiple generations) for any management actions 
to be realized and reflected in population abundance indices. 
Similarly, the impact of present threats to the subspecies could be 
realized in the form of noticeable population declines within this time 
frame, as demonstrated by the very low PBR estimate for the dolphin and 
current mortality rate of 1.5 percent. As the main operative threats to 
the subspecies include habitat destruction and entanglement in fishing 
gear, this time frame would allow for reliable predictions regarding 
the impact of current levels of fishery-related mortality and the 
previously discussed impacts of habitat destruction as a result of land 
reclamation and other activities on the biological status of the 
Taiwanese humpback dolphin.
    In determining the extinction risk of a species (and in this case, 
a subspecies), it is important to consider both the demographic risks 
facing the species as well as current and potential threats that may 
affect the species' status. To this end, a demographic risk analysis 
was conducted for the Taiwanese humpback dolphin. A demographic risk 
analysis is an assessment of the manifestation of past threats that 
have contributed to the species' current status and informs the 
consideration of the biological response of the species to present and 
future threats. This analysis evaluated the population viability 
characteristics and trends available for the dolphin, such as 
abundance, growth rate/productivity, spatial structure and 
connectivity, and diversity, to determine the potential risks these 
demographic factors pose to the subspecies. The information from this 
demographic risk analysis was considered alongside the information 
previously presented on threats to the subspecies, including those 
related to the factors specified by the ESA section 4(a)(1)(A)-(E) (and 
summarized in a separate Threats Assessment section below) and used to 
determine an overall risk of extinction for the Taiwanese humpback 
dolphin. Thus, scientific conclusions about the overall risk of 
extinction faced by the Taiwanese humpback dolphin under present 
conditions and in the foreseeable future are based on our evaluation of 
the subspecies' demographic risks and section 4(a)(1) threat factors. 
Our assessment of overall extinction risk considered the likelihood and 
contribution of each particular factor, synergies among contributing 
factors, and the cumulative impact of all demographic risks and threats 
on the subspecies.
    Section 4(b)(1)(A) of the ESA requires the Secretary, when making a 
listing determination for a species, to take into consideration those 
efforts, if any, being made by any State or foreign nation, or any 
political subdivision of a State or foreign nation, to protect the 
species. Therefore, prior to making a listing determination, we also 
assess such protective efforts to determine if they are adequate to 
mitigate the existing threats.

Evaluation of Demographic Risks


    We identified the critically low population abundance of the 
Taiwanese humpback dolphin as the demographic factor contributing most 
heavily to the subspecies' risk of extinction. With fewer than 100 
individuals and low productivity, even a single human-caused mortality 
per year is expected to negatively impact the subspecies' continued 
viability. For example, current annual mortality is estimated at 1.5 
percent (Wang et al., 2012) and recent PVAs, which model future 
scenarios taking into account increasing threats of fishing and habitat 
loss, confirm the unsustainable decline of the population 
(Ara[uacute]jo et al., 2014; Huang and Karczmarski, 2014; Huang et al., 
2014). In fact, both available PVA assessments conclude that the 
subspecies is in danger of going extinct (Wang et al., 2016). Overall, 
the small and declining population size of the Taiwanese humpback 
dolphin contributes to a high risk of extinction, which is compounded 
by a variety of ongoing threats to the population and its habitat.

Growth Rate/Productivity

    The Taiwanese humpback dolphin is associated with a slow rate of 
reproduction, long calving intervals, low recruitment rates and a long 
period of female-calf association. A recent study on the reproductive 
parameters of

[[Page 28807]]

the Taiwanese humpback dolphin indicates low calf survival rate and 
fecundity (Chang et al., 2016). For the Taiwanese humpback dolphin, low 
fecundity is likely caused by current threats of habitat contamination, 
stress, and prey disruption (Chang et al., 2016). As such, ongoing 
exposure to pollution and stress derived from interactions with 
anthropogenic activity may act to further reduce reproductive rates of 
this subspecies in the future. Trends of decreasing reproductive rate 
are likely to prevent the population's adaptability to stress and 
impede its ability to increase population levels, even if mitigation 
efforts are made to address other threats such as bycatch and habitat 
destruction. Overall, the Taiwanese humpback dolphin's reproductive 
rate may be expected to decrease over time without efforts to mitigate 
habitat contamination and stress due to anthropogenic activity 
occurring throughout the population's range. For the Taiwanese humpback 
dolphin, a low rate of reproduction and fecundity now, and likely 
reductions in those rates in the future, contribute to a high risk of 

Spatial Structure/Connectivity

    As previously discussed, genetic data are not available for the 
Taiwanese humpback dolphin; therefore, the genetic connectivity within 
the population cannot be directly assessed. In such a small population, 
however, social behavior and habitat connectivity may provide clues to 
the connectivity of the population as a whole. For the Taiwanese 
humpback dolphin, habitat includes a very narrow strip of near shore 
waters. Analysis of social behavior of the population has revealed 
significant and high levels of interconnectedness and gregarious 
behavior across this habitat range (Dungan, 2011; Dungan et al., 2016). 
The population is not subdivided into smaller social groups, as is the 
case for larger mainland Chinese populations (Dungan, 2011). Rather, 
the Taiwanese humpback dolphin exhibits high social cohesion relating 
to its strong population isolation, low abundance, confined geographic 
distribution, and anthropogenic stressors that have diminished the 
biological productivity of Taiwan's west coast over the last ~60 years 
(Dungan et al., 2016; Dungan, 2011). As such, the subspecies' social 
structure may be unusual relative to other S. chinensis populations in 
that individual dolphins appear to be using stronger, longer-lasting 
relationships in order to cope with these environmental and demographic 
differences (Dungan et al., 2016).
    As previously discussed, the high social cohesion observed in the 
Taiwanese humpback dolphin is most likely related to cooperative calf 
rearing; this behavior is thought to be an adaptive response to the 
dolphin's degraded, geographically restricted environment (which makes 
it difficult for mothers to support offspring on their own), and to 
their small population size (which has likely increased the relatedness 
of individuals) (Dungan, 2011). The social structure of this small 
population may be disrupted by several factors. For instance, damming 
of freshwater input or construction and land reclamation preventing the 
transit of individuals across its near shore range may lead to genetic 
and social fragmentation. Currently, the direct impact of habitat 
alteration on the genetic and social connectivity of the Taiwanese 
humpback dolphin is based on limited data. Disruption of social 
structure through mortality or habitat fragmentation may hinder the 
transfer of information and destabilize the community structure that 
aids in the adaptability of the small population in the future. Current 
threats to habitat, fishing entanglement, and direct mortality continue 
to increase, and may disrupt the social stability and physical 
connectivity among individuals of the subspecies, particularly through 
the deaths of breeding females. However, the extent to which these 
effects directly impact the connectivity of the small and isolated 
population remains uncertain. Based on the narrow habitat range and 
isolated nature of the population, with high within-population 
connectivity, continued alteration and fragmentation of this 
connectivity due to increasingly constricted habitat may hinder its 
future ability to adapt to threats, and, therefore, contributes 
moderately to the subspecies' risk of extinction.


    While data do not exist to address the genetic diversity of the 
Taiwanese humpback dolphin, there are several reasons to believe that 
diversity is reduced in the subspecies. First, with fewer than 100 and 
possibly fewer than 75 individuals in this reproductively isolated 
subspecies (which is well below the minimum population size (i.e., at 
least 250 individuals) required for marine mammals to resist stochastic 
genetic diversity loss (Huang et al., 2014)), the gene pool may be 
experiencing critical bottlenecks. Next, social structure is highly 
connected in the population. This suggests that genetic substructure 
within the population does not exist, and diversification within the 
population is not supported by current environmental or behavioral 
mechanisms. Low diversity may contribute to low capacity for the 
population to adapt to changes in the marine environment projected in 
future climate scenarios. The combination of low diversity and small 
population size most likely increases the population's vulnerability to 
current and increasing threats. Insufficient data are available to 
directly determine the effect of small population size on the genetic 
diversity of the population. However, although insufficient data are 
available, evidence from abundance and social structure suggest that 
diversity is likely low, and may contribute moderately to the 
extinction risk of the subspecies.

Summary of Factors Affecting the Taiwanese Humpback Dolphin

    As described above, section 4(a)(1) of the ESA and NMFS' 
implementing regulations (50 CFR 424.11(c)) state that we must 
determine whether a species (or in this case, a subspecies) is 
endangered or threatened because of any one or a combination of the 
following factors: The present or threatened destruction, modification, 
or curtailment of its habitat or range; overutilization for commercial, 
recreational, scientific, or educational purposes; disease or 
predation; the inadequacy of existing regulatory mechanisms; or other 
natural or manmade factors affecting its continued existence. We 
evaluated whether and the extent to which each of the foregoing factors 
contributed to the overall extinction risk of the Taiwanese humpback 
dolphin. We summarize information regarding each of these threats below 
according to the factors specified in section 4(a)(1) of the ESA. The 
best available information indicates that habitat destruction, 
modification, or curtailment of the subspecies' habitat or range (e.g., 
land reclamation, fresh water diversion, and pollution) and other 
natural or manmade factors (e.g., bycatch and fisheries entanglement 
and vessel strikes) contribute significantly to the subspecies' risk of 
extinction. We also determined that the inadequacy of existing 
regulatory mechanisms to control these threats is also contributing 
significantly to the dolphin's extinction risk. We determined that 
overutilization for commercial, recreational, scientific or educational 
purposes, disease, or predation are not operative threats on the 
species, although we do recognize that these threats may act 
synergistically with the more high-risk threats. See Whittaker and 
Young (2017) for additional discussion of all ESA section 4(a)(1) 
threat categories.

[[Page 28808]]

Destruction, Modification, or Curtailment of the Species Habitat or 

    As previously discussed in the Range, Distribution and Habitat Use 
section of this proposed rule, the Taiwanese humpback dolphin is an 
obligatory shallow water inshore species known for its restricted 
distribution and narrow habitat selectivity; thus, degradation of 
coastal habitats can have significant consequences for the subspecies, 
including impacts to persistence and distribution of the subspecies 
(Karczmarski et al., 2016). Like many estuarine habitats, that of the 
Taiwanese humpback dolphin is negatively impacted by highly 
concentrated human activity. In fact, out of Taiwan's human population 
of 23 million, approximately 90 percent live in counties bordering the 
west coast of Taiwan, and thus abutting the Taiwanese humpback 
dolphin's habitat (Ross et al., 2010). In addition to high population 
density, the coastal region is associated with persistent industrial 
development, land reclamation, and freshwater diversion, all of which 
destroy and degrade estuarine habitat upon which the Taiwanese humpback 
dolphin depends (Sheehy, 2009; Thamarasi, 2014). Below, we discuss 
several factors that may be contributing to the destruction, 
modification, or curtailment of the Taiwanese humpback dolphin's 
habitat and/or range, including coastal development/land reclamation, 
freshwater diversion, and contaminants/pollutants.
    Land reclamation due to industrial activity and coastal development 
contributes to widespread loss and degradation of Taiwanese humpback 
dolphin habitat. Over the past three decades, the west coast of Taiwan 
has undergone large alterations of coastal environments due to 
embankment, land reclamation, coastal construction, and shoreline 
development, including the construction of break-walls and dredging 
activities. These activities have increased over the last 50 years and 
are expected to continue into the future, largely unchecked (Wang et 
al., 2004a; Wang et al., 2007a; Karczmarski et al., 2016). In fact, 
recent studies have documented extensive loss of native estuarine 
habitat across the Taiwanese humpback dolphin's range. For example, 
from 1995 to 2007, actions taken to control for erosion and flooding, 
as well as the expansion of structures such as fishing ports, power 
plants, and other public facilities, resulted in a 20 percent decline 
in natural coastline within the Taiwanese humpback dolphin's habitat 
(Wang et al., 2016).
    Another study estimated that land reclamation activities since 1972 
have destroyed over 222 km\2\ of habitat along the western coast of 
Taiwan, equating to 23 percent and 40 percent of dolphin habitat and 
foraging habitat, respectively (Karczmarski et al., 2016). However, the 
authors note that this is likely an underestimation of true impacts, as 
the study only considered habitat loss due to land reclamation and did 
not account for other impacts to the dolphin's habitat (Karczmarski et 
al., 2016). Results of this study indicate that the dolphin likely had 
a continuous distribution prior to any land reclamation activities, 
whereas the subspecies' current distribution appears fragmented into 
two zones separated by an area of potential avoidance. Therefore, 
Karczmarski et al. (2016) concluded that the current discontinuous 
distribution of Taiwanese humpback dolphins is likely due to varying 
levels of habitat degradation rather than ``natural patchiness of their 
    In contrast, Dares et al. (2017) found that Taiwanese humpback 
dolphins exhibited temporal and spatial variation in mean densities 
across their range, and that dolphin density was not directly linked to 
any environmental factors (e.g., depth, sea surface temperature, 
salinity, and proximity to the nearest source of fresh water). In fact, 
all metrics analyzed in the study, including dolphin sightings, dolphin 
density, and mother-calf pairs, were higher in waters adjacent to major 
reclamation projects as compared to more natural waters where major 
reclamation activities had not occurred. Unlike other cetacean species, 
Taiwanese humpback dolphins are confined to a relatively small amount 
of suitable habitat and restricted to shallow estuarine waters; 
therefore, the dolphins do not have the option to relocate to other 
areas when high quality habitats are degraded or lost to reclamation 
activities (Dares et al., 2017). Therefore, the authors conclude that 
``rather than a real preference for waters adjacent to reclaimed 
coastlines'' the patterns observed in the study are likely because the 
locations of these large construction sites and activities are in close 
proximity to the two largest estuaries in the range of the subspecies 
(Dares et al., 2017).
    Despite the differences in distribution and habitat use observed in 
these recent studies, the large elimination of suitable habitat 
negatively affects the Taiwanese humpback dolphin in several ways. 
First, habitat fragmentation due to high levels of industrial 
development may reduce connectivity among estuaries along the narrowly 
distributed range of the population. This can physically limit the 
ability of individuals to associate with each other, which could have 
detrimental impacts on the dolphin's reproductive output and calf 
survivorship, particularly given the subspecies' high social cohesion 
and dependence on cooperative calf-rearing behaviors (Dungan et al., 
2016). Next, waste discharge from industrial activity leads to water 
and sediment contamination. Given the extremely limited availability of 
suitable habitat for the dolphin, use of lower quality habitat near 
coastal developments because of land reclamation can also expose the 
dolphins to areas of higher effluent discharge and pollutants (Dares et 
al., 2017). Finally, dredging and hydraulic sand fill methods used 
frequently for industrial land reclamation in the area not only 
encroach upon limited habitat, but also have the potential to disrupt 
the distribution of vital prey species of the population (Ross et al., 
2010; Dungan et al., 2011).
    In addition to land reclamation, fresh water diversion likely has 
significant impacts to the Taiwanese humpback dolphin, as the 
subspecies is dependent upon freshwater inflow to support the 
productivity and ecosystem health of its estuarine habitat. This 
habitat need of freshwater inflow for the Taiwanese humpback dolphin is 
similar to that shown for the PRE population of humpback dolphins in 
mainland China, where freshwater inflow has been shown to support 
steady estuarine ecosystem production upon which the dolphin relies for 
prey (Jefferson and Hung, 2004). This freshwater flow is drastically 
reduced by dams, flood control, and river diversions related to 
industrial development and diversion for agricultural and municipal 
purposes (Dungan et al., 2011). In Taiwan, freshwater flow from all 
major rivers to estuaries has decreased by as much as 80 percent due to 
anthropogenic diversion (Ross et al., 2010). Landsat data also show a 
drastic reduction and weakening of annual discharge from major rivers 
along Taiwan's west coast since 1972, as indicated by the reduced width 
of the channel and alluvial fans at river mouths (Karczmarski et al., 
2016). Dams are already in place for many rivers in Western Taiwan, and 
have resulted in widespread loss of estuarine mudflat habitat, which is 
vital to Taiwanese humpback dolphin foraging and productivity. For 
example, the Coshui (Juoshuei) River that once

[[Page 28809]]

supplied sediment to the Waisanding sand bar has been diverted and 
restricted by the Formosa Petrochemical Corporation plant, resulting in 
shifts and shrinking of the sand bar (Chen, 2006). Taiwanese dams and 
their total capacity have increased exponentially over the past 
century, resulting in significant loss and alteration of natural 
estuarine systems. Finally, pollution and habitat contamination pose a 
threat to the health of long-lived species such as the humpback 
dolphin. Due to concentrated industrial and human activity, high levels 
of pollution are discharged into the habitat of the Taiwanese humpback 
dolphin (Wang et al., 2007a). The sources of these pollutants include 
marine boat repair, fish processing, fueling stations, ship dumping, 
pipeline leakage, municipal and residential waste, industrial effluent, 
and livestock runoff (Ross et al., 2010). The discharge of toxic 
pollutants into coastal waters of Taiwan is largely unregulated. For 
instance, an estimated 740,000 tons of waste oil from boats enters the 
marine environment in Taiwan each year (Wang et al., 2007b). In 
addition, over 70 percent of wastewater is discharged into river 
systems untreated, and subsequently runs off into near shore estuarine 
habitat (Chen et al., 2007). Particularly damaging are persistent 
organic, heavy metal, and trace metal pollutants which negatively 
interact with cetacean development and reproduction and are associated 
with carcinogenic and teratogenic properties (Reijnders, 2003; Ramu et 
al., 2005). These toxins have been found to accumulate and become 
concentrated in the marine sediment off the coast of Taiwan affected by 
freshwater input, impacting the Taiwanese humpback dolphin habitat 
(Chen et al., 2007; Hung et al., 2010). Even toxins which were banned 
in the 1980s, such as polychlorinated biphenyls (PCBs), remain present 
in poorly maintained machinery and industrial equipment, thus their 
accumulation is expected to continue in the future (Chou et al., 2004).
    Pollution can affect the Taiwanese humpback dolphin in two ways: 
Directly influencing the health of the animal or influencing prey that 
the dolphin later ingests, thus leading to bioaccumulation of toxins in 
the dolphin. To date, only one study has analyzed the potential 
bioaccumulation of toxins specifically for the Taiwanese humpback 
dolphin population. Riehl et al. (2012), using a life-history based 
contaminant accumulation model for marine mammals, estimated that 68 
percent of the population is at risk for immunotoxicity based on a 17 
mg/kg lipid weight (LW) threshold for immunotoxicity (noting that there 
are several lower level thresholds shown to impact the health of marine 
mammals). Model outputs using a ``best-case'' scenario (e.g., diet of 
100 percent Johnius spp.) resulted in average adult males reaching the 
threshold concentration just prior to turning 9.3 years of age. In 
contrast, the average adult female would only acquire enough PCBs to 
reach concentrations of 2.84 mg/kg LW due to offloading much of their 
body burden to their offspring after giving birth (Riehl et al., 2012). 
Although the study was based on limited species-specific data inputs to 
the model, humpback dolphins in the PRE, affected by similar threats of 
industrial development and habitat contamination, have demonstrated 
elevated concentrations of organochlorines including PCBs, 
hexachlorocyclohexanes (HCHs), and dichlorodiphenyltrichloroethanes 
(DDTs) (Parsons, 2004; Ramu et al., 2005; Jefferson et al., 2006). For 
example, in humpback dolphins off the coast of Hong Kong, the 
concentration of DDTs was as high as 470 [mu]g/g LW, and PCBs as high 
as 78 [mu]g/g (Ramu et al., 2005). Toxicity analysis (which compares 
these concentrations with known toxic effects from other marine 
mammals) strongly suggests that these chemicals impair reproduction and 
suppress immune function in the Indo-Pacific humpback dolphin (Ramu et 
al., 2005). This is particularly concerning given the already low 
reproductive rate of the dolphin.

Overutilization for Commercial, Recreational, Scientific or Educational 

    We assessed two factors that may contribute to the overutilization 
of the subspecies: Whale watching and scientific research. While some 
whale watching and recreational observation of marine mammals occurs 
off the coast of Taiwan, it is unlikely that these activities 
contribute heavily to the extinction risk for the Taiwanese humpback 
dolphin relative to other threats. However, some tours targeting the 
Taiwanese humpback dolphin have been permitted to operate despite 
recommendations against any boat-based dolphin watch tour targeting the 
subspecies (Wang, pers. comm., 2017; Wang et al., 2007a). Therefore, 
while whale watching tours on their own are unlikely to pose a 
significant threat to the dolphin, any additional stressor on the 
population likely acts synergistically with other more prominent 
threats and contributes to the subspecies' extinction risk.
    It is also unlikely that scientific monitoring has a negative 
impact on the Taiwanese humpback dolphin. The dolphin was only first 
observed in 2002, and since then several scientific surveys have sought 
to characterize its status and abundance. The low frequency of these 
surveys, and reliance on non-invasive photo identification, are 
unlikely to pose serious threats to the subspecies.

Inadequacy of Existing Regulatory Mechanisms

    There are few regulations in place for the protection of the 
Taiwanese humpback dolphin. For example, the Taiwanese humpback dolphin 
is listed under Taiwan's Wildlife Conservation Act as a Level I 
protected species, which grants species the highest level of legal 
protection. Article 4 of the Act designates humpback dolphins as 
``protected wildlife'', and Article 18 states that these animals are 
``not to be disturbed, abused, hunted [or] killed'' (Wang et al., 
2016). Nonetheless, there appear to be no associated regulatory or 
enforcement actions for the prevention of bycatch and entanglement of 
the population, or extensive habitat degradation (Wang et al., 2016). 
For example, several years after Ross et al. (2010) published 
recommendations for legally protecting the confirmed and suitable 
habitat for the Taiwanese humpback dolphins, the Forestry Bureau of 
Taiwan proposed ``Major Wildlife Habitat'' for the dolphins in 2014; 
however, the proposed protected area did not cover the minimum area 
recommended for protection (Wang et al., 2016). Given the already 
restricted amount of suitable habitat available to the dolphin, 
providing legal protection for an area that does not cover the 
subspecies' entire distribution may put the dolphins at risk of 
encountering increased threats occurring just outside the protected 
area (also known as the ``edge effect''; see original citations in Wang 
et al., 2016). Furthermore, regardless of potential inadequacies of the 
proposed protected area, the ``Major Wildlife Habitat'' proposal has 
not yet been implemented (Wang et al., 2016). Therefore, based on 
current knowledge of the population, and despite providing the highest 
level of legislative protection, the Wildlife Conservation Act appears 
inadequate to control for the primary threats to the species and has 
thus far proven unsuccessful in slowing population decline.
    While many recommendations have been made to guide the future 
conservation and recovery of the

[[Page 28810]]

population (Wang et al., 2004a; Wang et al., 2007a; Ross et al., 2010; 
Ross et al., 2011), no current regulatory mechanisms are in place to 
address the major threats to the subspecies and its future viability. 
Development and industrialization of the region are largely 
unregulated. Likewise, fishing and marine mammal bycatch are also 
    Therefore, based on the foregoing information, we conclude that 
existing regulations for the Taiwanese humpback dolphin are inadequate. 
That is, the laws that are in place currently are not effectively 
controlling for the main identified threats to the species (e.g., 
habitat destruction and fishing interactions) and will likely not 
prevent future population decline.

Other Natural or Manmade Factors Affecting Its Continued Existence

    We assessed several potential threats that fall under the category 
of Other Natural or Manmade Factors, including bycatch and entanglement 
in fishing gear, vessel strikes, acoustic disturbance, and climate 
change. Among these threats, injury and mortality due to bycatch and 
entanglement in fishing gear and vessel strikes were by far the most 
significant threats to the continued existence of the Taiwanese 
humpback dolphin. We discuss these threats in detail below. Detailed 
information on the other threats (i.e., acoustic disturbance and 
climate change) can be found in the draft status review report 
(Whittaker and Young, 2017).
    As noted previously, entanglement and mutilation due to 
interactions with fishing gear are likely the most serious direct and 
immediate threat to the Taiwanese humpback dolphin (Wang et al., 2016; 
Wang et al., 2017). Bycatch poses a significant threat to small 
cetaceans in general, where entanglement in fishing gear results in 
widespread injury and mortality (Read et al., 2006). Taiwanese 
fisheries reports indicate that entanglement in fishing gear kills 
thousands of small cetaceans in the region (Chou, 2006). Although there 
are many types of fishing gear used throughout the subspecies' habitat, 
the two fishing gear types most hazardous to small cetaceans are 
gillnets and trammel nets, thousands of which are set in coastal waters 
off western Taiwan (Dungan et al., 2011; Slooten et al., 2013).
    Injury due to entanglement is evident in the Taiwanese humpback 
dolphin population, identified by characteristic markings on the body, 
including constrictive line wraps, and direct observation of gear 
wrapped around the dolphin (Slooten et al., 2013). One study determined 
that over 30 percent of the Taiwanese humpback dolphin population 
exhibits evidence of fisheries interactions including wounds, scars, 
and entanglement (Wang et al., 2007a; Slooten et al., 2013), with 59.2 
percent of injuries (lethal and non-lethal) observed confirmed to have 
originated from fisheries interactions (Slooten et al., 2013). In a 
more recent study that expands upon Slooten et al. (2013), Wang et al. 
(2017) determined that nearly 60 percent of the individuals examined in 
the study (n = 78) bore major injuries caused by human activities, with 
93 major injuries recorded on 46 individuals. The authors defined 
``major injuries'' as those that would likely comprise the dolphin's 
health, survivorship or reproductive potential. Not only was a large 
proportion of the population injured, more than half of the individuals 
suffered multiple injuries, with several new injuries observed. 
Consequently, this means that the risk of injury by human activities is 
ongoing. In fact, from 2007 to 2015, 11 new human-caused injuries were 
recorded on 9 individuals. Therefore, the population incurred a minimum 
of 1.38 new injuries each year of the study, which resulted in a total 
major injury rate of 1.13 individuals/year (Wang et al., 2017). 
However, the authors note that despite the fact that all metrics 
evaluated in the study were high, they were still likely underestimates 
of the total impacts. For example, fatal injuries in which the animal 
dies immediately or soon after could not be considered and thus were 
not factored into the overall measure of impact. Two individuals have 
been found dead since 2009 with indications of gillnet entanglement 
injuries (Wang et al., 2017) and thus far, there has been no action to 
reduce any of the major threats identified more than a decade ago at 
the first workshop on the conservation and research needs of the 
subspecies (Wang et al., 2004a; Wang et al., 2017). Overall, without 
immediate actions to control for threats from local fisheries 
(especially net fisheries) and other major threats identified to the 
subspecies, the Taiwanese humpback dolphin likely faces imminent 
extinction (Wang et al., 2017).
    In addition to direct effects of fishing activity on the Taiwanese 
humpback dolphin, indirect effects of fishing include: Depletion of 
prey resources, pollution, noise disturbance, altered behavioral 
responses to prey aggregation in fishing gear, and potential changes to 
social structure arising from the deaths of individuals. Individuals of 
the Taiwanese humpback dolphin have shown potential evidence of 
disturbance due to such effects (Slooten et al., 2013). For example, 
recent surveys have observed dolphins with emaciated and poor body 
condition, suggesting declines in prey abundance, increased foraging 
effort, or disease (Slooten et al., 2013). While most Taiwanese 
humpback dolphin prey species are small and not commercially valuable 
(Barros et al., 2004), decreases in their abundance due to bycatch and 
subsequent fishmeal production may lead to over-exploitation, and 
reduce prey availability for the dolphin (Slooten et al., 2013). 
Increased prey aggregation due to fishing can also attract mothers and 
calves, putting them at greater risk of entanglement and injury; this 
has been observed in the PRE population, and is most likely behavior 
common to the Taiwanese humpback dolphin as well (Jefferson, 2000). 
Finally, death and injury of individuals due to fishing activity can 
disrupt social structure, which may affect the survival of calves or 
transfer of generational information throughout the social network. For 
example, loss of a mature female may impact the trajectory of learning 
and survival techniques passed on to a calf in its first several years.
    In addition to bycatch and entanglement, fishing activities can 
affect dolphins by increasing the likelihood of vessel strikes due to 
increased boat traffic. The waters off Taiwan are highly concentrated 
with human boat activity, including transportation, industrial 
shipping, commercial fishing, sand extraction, harbor dredging, and 
commercial dolphin watching. This activity is unmitigated, and its 
concentration has increased dramatically over the past few decades. In 
fact, the trend in boating and fishing activity in the region has 
increased by more than 750 percent since the 1950s, and its increase is 
expected to continue into the foreseeable future (Huang and Chuang, 
2010). Fishing vessels alone contribute a large fraction of this 
boating activity; an estimated 6,300 fishing vessels are currently 
active inside the dolphins' habitat (operating from ports in the six 
coastal counties fronting the dolphins' habitat), and 45 percent of 
them are regularly engaged in fishing coastal waters (Slooten et al., 
2013). The fleet is over-capitalized due to technological improvements, 
and thus fishing pressure and negative interactions between fishing 
gear/vessels and cetaceans are increasing (Wang et al., 2007b). 
Additionally, this traffic is

[[Page 28811]]

unregulated, and poses a threat to the limited and narrow habitat 
available to the subspecies. The noise from these vessels may be 
disorienting for the dolphins, which rely upon acoustic sensory systems 
to communicate, forage, and interact with their environment, and thus 
increase the potential for a strike. In addition, individuals, 
especially females and calves, may be attracted to fishing vessels due 
to elevated prey concentration, which can lead to mortality via vessel 
strike. Humpback dolphins off the coast of Hong Kong, which interact 
with comparable levels of vessel traffic and face similar threats to 
habitat, have demonstrated unmistakable evidence of propeller cuts on 
their bodies, and vessel strikes have been determined as the conclusive 
cause of mortality in a high proportion of stranding incidents 
(Jefferson, 2000).
    Aside from direct mortality, interaction with vessel traffic may 
alter behavior of the dolphin, causing stress, reducing foraging 
efficiency, increasing the threat of predation, and altering behaviors 
that support its productivity. For instance, in individuals off the 
coast of Hong Kong, mother-calf pairs demonstrated the greatest level 
of disturbance by vessel traffic; it has been hypothesized that 
separation of the calf due to vessel disturbance could easily increase 
risk of predation, aside from the direct injury of a vessel strike (Van 
Parijs and Corkeron, 2001).

Overall Extinction Risk Summary

    We identified several threats that likely affect the continued 
survival of the Taiwanese humpback dolphin, including destruction, 
modification, and curtailment of its habitat (e.g., land reclamation, 
industrial, agricultural, and municipal pollution, and river 
diversion), and other natural or manmade factors, such as bycatch and 
entanglement in fishing gear, vessel strikes, and acoustic disturbance. 
Of these threats, destruction and modification of habitat through land 
reclamation, river flow diversion, and pollution, as well as 
entanglement and bycatch pose the highest risk of extinction for the 
Taiwanese humpback dolphin. These threats are immediate, and intensity 
of these threats is likely to increase in the future. Regulations to 
mitigate these threats are not currently in place, and plans for 
mitigation have not yet been implemented. The analysis of demographic 
factors above identified several characteristics that elevate the 
population's vulnerability to these threats. For example, heavily 
diminished and declining population size drastically elevates the 
impact of even a single mortality event. Evidence suggests that 
diversity of the population is low, which reduces the resiliency of the 
population to threats and changes in its habitat. The population 
appears to be cohesive, most likely due to low population size and the 
narrow extent of its habitat. The potential for future disruption of 
social structure due to habitat fragmentation may heavily impact the 
transfer of generational information, calf survival, and foraging 
success. Finally, the population exhibits naturally low rates of 
reproduction and productivity, and data suggest that stress and habitat 
pollution act to further reduce the population's fecundity and 
productivity. Given these demographic characteristics, the 
aforementioned threats work synergistically to disrupt social 
structure, increase stress, limit food availability, and reduce 
fecundity while resulting in direct loss through mortality, injury, and 
prevention of population recovery. Due to the immediacy and intensity 
of threats, and demographic characteristics increasing the 
vulnerability of the population, we have concluded that the Taiwanese 
humpback dolphin has an overall high risk of extinction.

Conservation Efforts

    Section 4(b)(1)(A) of the ESA requires the Secretary, when making a 
listing determination for a species, to take into account those 
efforts, if any, being made by any State or foreign nation to protect 
the species.
    Non-governmental organizations (NGOs), scientists, activists and 
residents of Taiwan have invested significant amounts of time and 
resources into the conservation of the Taiwanese humpback dolphin (Wang 
et al., 2016). For example, a series of workshops have been conducted 
to discuss the conservation of the Taiwanese humpback dolphin. These 
took place in 2004, 2007, 2011 and 2014, bringing together scientists, 
policy makers, and international partners to discuss conservation 
options for the subspecies. The overarching goals of each workshop were 
to define the conservation status, current threats, and outline 
potential conservation measures that would best help to improve the 
status of the subspecies. Since these workshops, research on the 
population has increased greatly, and understanding of the subspecies' 
abundance and population trends have improved. However, actions have 
yet to be taken by the local government to reduce any of the major 
existing threats faced by the subspecies (Wang et al., 2016). We could 
not find any additional information on protective efforts for the 
Taiwanese humpback dolphin that would reduce its current risk of 

Proposed Determination

    Section 4(b)(1) of the ESA requires that we make listing 
determinations based solely on the best scientific and commercial data 
available after conducting a review of the status of the species and 
taking into account those efforts, if any, being made by any state or 
foreign nation, or political subdivisions thereof, to protect and 
conserve the species. We have independently reviewed the best available 
scientific and commercial information, including the petition, public 
comments submitted on the 90-day finding (81 FR 1376; January 12, 
2016), the draft status review report (Whittaker and Young, 2017), and 
other published and unpublished information, and we have consulted with 
species experts and individuals familiar with the Taiwanese humpback 
dolphin subspecies. We considered each of the section 4(a)(1) factors 
to determine whether it contributed significantly to the extinction 
risk of the species on its own. We also considered the combination of 
those factors to determine whether they collectively contributed 
significantly to the extinction risk of the species. Therefore, our 
determination set forth below is based on a synthesis and integration 
of the foregoing information, factors and considerations, and their 
effects on the status of the subspecies throughout its range.
    We conclude that the Taiwanese humpback dolphin is presently in 
danger of extinction throughout its range. We summarize the factors 
supporting this conclusion as follows: (1) The best available 
information indicates that the subspecies has a critically small 
population of less than 100 individuals, which is likely declining; (2) 
the Taiwanese humpback dolphin has a very restricted range, occurring 
only in the shallow waters off the western coast of Taiwan; (3) the 
subspecies possesses life history characteristics that increase its 
vulnerability to threats, including that it is long-lived and has a 
late age of maturity, slow population growth, and low rate of 
reproduction and fecundity; (4) the subspecies is confined to limited 
habitat in a heavily impacted area of coastline where ongoing habitat 
destruction (including coastal development, land reclamation, and fresh 
water diversion) contributes to a high risk of extinction; (5) the 
Taiwanese humpback dolphin is

[[Page 28812]]

experiencing unsustainable rates of fisheries interactions, including 
mortality and major injuries due to bycatch and entanglement in fishing 
gear; and (6) existing regulatory mechanisms are inadequate for 
addressing the most important threats of habitat destruction and 
fisheries interactions.
    As a result of the foregoing findings, which are based on the best 
scientific and commercial data available, we conclude that the 
Taiwanese humpback dolphin is presently in danger of extinction 
throughout all of its range. Accordingly, the Taiwanese humpback 
dolphin meets the definition of an endangered species, and thus 
warrants listing as an endangered species at this time.

Effects of Listing

    Conservation measures provided for species listed as endangered or 
threatened under the ESA include the development and implementation of 
recovery plans (16 U.S.C. 1533(f)); designation of critical habitat, if 
prudent and determinable (16 U.S.C. 1533(a)(3)(A)); a requirement that 
Federal agencies consult with NMFS under section 7 of the ESA to ensure 
their actions do not jeopardize the species or result in adverse 
modification or destruction of designated critical habitat (16 U.S.C. 
1536); and, for endangered species, prohibitions on the import and 
export of any endangered species; the sale and offering for sale of 
such species in interstate or foreign commerce; the delivery, receipt, 
carriage, shipment, or transport of such species in interstate or 
foreign commerce and in the course of a commercial activity; and the 
``take'' of such species within the U.S., within the U.S. territorial 
sea, or on the high seas (16 U.S.C. 1538). Recognition of the species' 
imperiled status through listing may also promote conservation actions 
by Federal and state agencies, foreign entities, private groups, and 

Identifying Section 7 Consultation Requirements

    Section 7(a)(2) (16 U.S.C. 1536(a)(2)) of the ESA and NMFS/FWS 
regulations require Federal agencies to confer with us on actions 
likely to jeopardize the continued existence of species proposed for 
listing, or that result in the destruction or adverse modification of 
proposed critical habitat. If a proposed species is ultimately listed, 
Federal agencies must consult on any action they authorize, fund, or 
carry out if those actions may affect the listed species or its 
critical habitat and ensure that such actions are not likely to 
jeopardize the continued existence of the species or result in adverse 
modification or destruction of critical habitat should it be 
designated. It is unlikely that the listing of this subspecies under 
the ESA will increase the number of section 7 consultations because the 
subspecies occurs outside of the United States and is unlikely to be 
affected by Federal actions.

Critical Habitat

    Critical habitat is defined in section 3 of the ESA (16 U.S.C. 
1532(3)) as: (1) The specific areas within the geographical area 
occupied by a species, at the time it is listed in accordance with the 
ESA, on which are found those physical or biological features (a) 
essential to the conservation of the species and (b) that may require 
special management considerations or protection; and (2) specific areas 
outside the geographical area occupied by a species at the time it is 
listed upon a determination that such areas are essential for the 
conservation of the species. ``Conservation'' means the use of all 
methods and procedures needed to bring the species to the point at 
which listing under the ESA is no longer necessary. Section 4(a)(3)(A) 
of the ESA (16 U.S.C. 1533(a)(3)(A)) requires that, to the extent 
prudent and determinable, critical habitat be designated concurrently 
with the listing of a species. However, critical habitat cannot be 
designated in foreign countries or other areas outside U.S. 
jurisdiction (50 CFR 424.12(g)). The Taiwanese humpback dolphin is 
endemic to Taiwan and does not occur within areas under U.S. 
jurisdiction. There is no basis to conclude that any unoccupied areas 
under U.S. jurisdiction are essential for the conservation of the 
subspecies. Therefore, we do not intend to propose any critical habitat 
designations for the subspecies.

Public Comments Solicited on Listing

    To ensure that the final action resulting from this proposal will 
be as accurate and effective as possible, we solicit comments and 
suggestions from the public, other governmental agencies, the 
scientific community, industry, environmental groups, and any other 
interested parties. Comments are encouraged on this proposal (See DATES 
and ADDRESSES). Specifically, we are interested in new or updated 
information regarding: (1) The range, distribution, and abundance of 
the Taiwanese humpback dolphin; (2) the genetics and population 
structure of the Taiwanese humpback dolphin; (3) habitat within the 
range of the Taiwanese humpback dolphin that was present in the past, 
but may have been lost over time; (4) any threats to the Taiwanese 
humpback dolphin (e.g., fishing gear entanglement, habitat destruction, 
etc.); (5) current or planned activities within the range of the 
Taiwanese humpback dolphin and their possible impact on the subspecies; 
(6) recent observations or sampling of the Taiwanese humpback dolphin; 
and (7) efforts being made to protect the Taiwanese humpback dolphin.

Role of Peer Review

    In December 2004, the Office of Management and Budget (OMB) issued 
a Final Information Quality Bulletin for Peer Review establishing 
minimum peer review standards, a transparent process for public 
disclosure of peer review planning, and opportunities for public 
participation. The OMB Bulletin, implemented under the Information 
Quality Act (Pub. L. 106-554), is intended to enhance the quality and 
credibility of the Federal government's scientific information, and 
applies to influential scientific information or highly influential 
scientific assessments disseminated on or after June 16, 2005. To 
satisfy our requirements under the OMB Bulletin, we obtained 
independent peer review of the status review report. Independent 
specialists were selected from the academic and scientific community 
for this review. All peer reviewer comments were addressed prior to 
dissemination of the final status review report and publication of this 
proposed rule.


    A complete list of all references cited herein is available upon 


National Environmental Policy Act

    Section 4(b)(1)(A) of the ESA restricts the information that may be 
considered when assessing species for listing and sets the basis upon 
which listing determinations must be made. Based on the requirements in 
section 4(b)(1)(A) of the ESA and the opinion in Pacific Legal 
Foundation v. Andrus, 675 F. 2d 825 (6th Cir. 1981), we have concluded 
that ESA listing actions are not subject to the environmental 
assessment requirements of the National Environmental Policy Act 

Executive Order 12866, Regulatory Flexibility Act, and Paperwork 
Reduction Act

    As noted in the Conference Report on the 1982 amendments to the 
ESA, economic impacts cannot be considered

[[Page 28813]]

when assessing the status of a species. Therefore, the economic 
analysis requirements of the Regulatory Flexibility Act are not 
applicable to the listing process.
    In addition, this proposed rule is exempt from review under 
Executive Order 12866. This proposed rule does not contain a 
collection-of-information requirement for the purposes of the Paperwork 
Reduction Act.

Executive Order 13132, Federalism

    In accordance with E.O. 13132, we determined that this proposed 
rule does not have significant Federalism effects and that a Federalism 
assessment is not required. Given that this subspecies occurs entirely 
outside of U.S. waters, there will be no federalism impacts because 
listing the subspecies will not affect any state programs.

List of Subjects in 50 CFR Part 224

    Endangered and threatened species, Exports, Imports, 

    Dated: June 20, 2017.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For the reasons set out in the preamble, 50 CFR part 224 is 
proposed to be amended as follows:


1. The authority citation for part 224 continues to read as follows:

    Authority: 16 U.S.C. 1531-1543 and 16 U.S.C 1361 et seq.

2. In Sec.  224.101, amend the table in paragraph (h), by adding an 
entry, by common name, ``Dolphin, Taiwanese humpback'' under ``Marine 
Mammals'' in alphabetical order, to read as follows:

Sec.  224.101  Enumeration of endangered marine and anadromous species.

* * * * *
    (h) * * *

                            Species \1\
--------------------------------------------------------------------  Citation(s) for     Critical
                                                    Description of        listing         habitat     ESA rules
          Common name            Scientific name     listed entity    determination(s)
                                                  * * * * * * *
Marine Mammals..................................................................................................
                                                  * * * * * * *
Dolphin, Taiwanese humpback...  Sousa chinensis    Entire            [Insert Federal             NA           NA
                                 taiwanensis.       subspecies.       Register page
                                                                      where the
                                                                      begins], [date
                                                                      of publication
                                                                      when published
                                                                      as a final rule].
                                                  * * * * * * *
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement,
  see 61 FR 4722; February 7, 1996), and evolutionarily significant units (ESUs) (for a policy statement, see 56
  FR 58612; November 20, 1991).

[FR Doc. 2017-13250 Filed 6-23-17; 8:45 am]