81 FR 29515 - Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List the Taiwanese Humpback Dolphin as Threatened or Endangered Under the Endangered Species Act

DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration

Federal Register Volume 81, Issue 92 (May 12, 2016)

We, NMFS, announce a 90-day finding on a petition to list the Taiwanese humpback dolphin (Sousa chinensis taiwanensis) range-wide as threatened or endangered under the Endangered Species Act (ESA). We find that the petition and information in our files present substantial scientific or commercial information indicating that the petitioned action may be warranted for the Taiwanese humpback dolphin. We will conduct a status review of the species to determine if the petitioned action is warranted. To ensure that the status review is comprehensive, we are soliciting scientific and commercial information pertaining to the species from any interested party.

[Federal Register Volume 81, Number 92 (Thursday, May 12, 2016)]
[Proposed Rules]
[Pages 29515-29521]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-11014]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Parts 223 and 224

[Docket No. 160413329-6329-01]
RIN 0648-XE571


Endangered and Threatened Wildlife; 90-Day Finding on a Petition 
To List the Taiwanese Humpback Dolphin as Threatened or Endangered 
Under the Endangered Species Act

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

ACTION: 90-day petition finding, request for information.

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SUMMARY: We, NMFS, announce a 90-day finding on a petition to list the 
Taiwanese humpback dolphin (Sousa chinensis taiwanensis) range-wide as 
threatened or endangered under the Endangered Species Act (ESA). We 
find that the petition and information in our files present substantial 
scientific or commercial information indicating that the petitioned 
action may be warranted for the Taiwanese humpback dolphin. We will 
conduct a status review of the species to determine if the petitioned 
action is warranted. To ensure that the status review is comprehensive, 
we are soliciting scientific and commercial information pertaining to 
the species from any interested party.

DATES: Information and comments on the subject action must be received 
by July 11, 2016.

ADDRESSES: You may submit comments, information, or data on this 
document, identified by the code NOAA-NMFS-2016-0041, by either of the 
following methods:
     Electronic Submissions: Submit all electronic public 
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.
    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

[[Page 29516]]

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 
anonymous).
    Copies of the petition and related materials are available on our 
Web site at http://www.fisheries.noaa.gov/pr/species/mammals/dolphins/indo-pacific-humpback-dolphin.html.

FOR FURTHER INFORMATION CONTACT: Chelsey Young, Office of Protected 
Resources, 301-427-8403.

SUPPLEMENTARY INFORMATION: 

Background

    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 petition asserts that new scientific 
and taxonomic information demonstrates that the Taiwanese humpback 
dolphin is actually a subspecies, and states that NMFS must reconsider 
the subspecies for ESA listing. Copies of the petition are available 
upon request (see ADDRESSES).

ESA Statutory, Regulatory, and Policy Provisions and Evaluation 
Framework

    Section 4(b)(3)(A) of the ESA of 1973, as amended (16 U.S.C. 1531 
et seq.), requires, to the maximum extent practicable, that within 90 
days of receipt of a petition to list a species as threatened or 
endangered, the Secretary of Commerce make a finding on whether that 
petition presents substantial scientific or commercial information 
indicating that the petitioned action may be warranted, and to promptly 
publish such finding in the Federal Register (16 U.S.C. 1533(b)(3)(A)). 
When it is found that substantial scientific or commercial information 
in a petition indicates the petitioned action may be warranted (a 
``positive 90-day finding''), we are required to promptly commence a 
review of the status of the species concerned, during which we will 
conduct a comprehensive review of the best available scientific and 
commercial information. In such cases, we conclude the review with a 
finding as to whether, in fact, the petitioned action is warranted 
within 12 months of receipt of the petition. Because the finding at the 
12-month stage is based on a more thorough review of the available 
information, as compared to the narrow scope of review at the 90-day 
stage, a ``may be warranted'' finding does not prejudge the outcome of 
the status review.
    Under the ESA, a listing determination may address a species, which 
is defined to also include subspecies and, for any vertebrate species, 
any DPS that interbreeds when mature (16 U.S.C. 1532(16)). A joint 
NMFS-U.S. Fish and Wildlife Service (USFWS) (jointly, ``the Services'') 
policy clarifies the agencies' interpretation of the phrase ``distinct 
population segment'' for the purposes of listing, delisting, and 
reclassifying a species under the ESA (61 FR 4722; February 7, 1996). A 
species, subspecies, or DPS is ``endangered'' if it is in danger of 
extinction throughout all or a significant portion of its range, and 
``threatened'' if it is likely to become endangered within the 
foreseeable future throughout all or a significant portion of its range 
(ESA sections 3(6) and 3(20), respectively, 16 U.S.C. 1532(6) and 
(20)). Pursuant to the ESA and our implementing regulations, we 
determine whether a species is threatened or endangered based on any of 
the following five section 4(a)(1) 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; and any other natural or manmade factors 
affecting the species' continued existence (16 U.S.C. 1533(a)(1), 50 
CFR 424.11(c)).
    ESA implementing regulations issued jointly by NMFS and USFWS (50 
CFR 424.14(b)) define ``substantial information'' in the context of 
reviewing a petition to list, delist, or reclassify a species as the 
amount of information that would lead a reasonable person to believe 
that the measure proposed in the petition may be warranted. In 
evaluating whether substantial information is contained in a petition, 
the Secretary must consider whether the petition: (1) Clearly indicates 
the administrative measure recommended and gives the scientific and any 
common name of the species involved; (2) contains detailed narrative 
justification for the recommended measure, describing, based on 
available information, past and present numbers and distribution of the 
species involved and any threats faced by the species; (3) provides 
information regarding the status of the species over all or a 
significant portion of its range; and (4) is accompanied by appropriate 
supporting documentation in the form of bibliographic references, 
reprints of pertinent publications, copies of reports or letters from 
authorities, and maps (50 CFR 424.14(b)(2)).
    At the 90-day finding stage, we evaluate the petitioners' request 
based upon the information in the petition including its references and 
the information readily available in our files. We do not conduct 
additional research, and we do not solicit information from parties 
outside the agency to help us in evaluating the petition. We will 
accept the petitioners' sources and characterizations of the 
information presented if they appear to be based on accepted scientific 
principles, unless we have specific information in our files that 
indicates the petition's information is incorrect, unreliable, 
obsolete, or otherwise irrelevant to the requested action. Information 
that is susceptible to more than one interpretation or that is 
contradicted by other available information will not be dismissed at 
the 90-day finding stage, so long as it is reliable and a reasonable 
person would conclude it supports the petitioners' assertions. In other 
words, conclusive information indicating the species may meet the ESA's 
requirements for listing is not required to make a positive 90-day 
finding. We will not conclude that a lack of specific information alone 
negates a positive 90-day finding if a reasonable person would conclude 
that the unknown information itself suggests an extinction risk of 
concern for the species at issue.
    To make a 90-day finding on a petition to list a species, we 
evaluate whether the petition presents substantial scientific or 
commercial information indicating the subject species may be either 
threatened or endangered, as defined by the ESA. First, we evaluate 
whether the information presented in the petition, along with the 
information readily available in our files, indicates that the 
petitioned entity constitutes a ``species'' eligible for listing under 
the ESA. Next, we evaluate whether the information

[[Page 29517]]

indicates that the species faces an extinction risk that is cause for 
concern; this may be indicated in information expressly discussing the 
species' status and trends, or in information describing impacts and 
threats to the species. We evaluate any information on specific 
demographic factors pertinent to evaluating extinction risk for the 
species (e.g., population abundance and trends, productivity, spatial 
structure, age structure, sex ratio, diversity, current and historical 
range, habitat integrity or fragmentation), and the potential 
contribution of identified demographic risks to extinction risk for the 
species. We then evaluate the potential links between these demographic 
risks and the causative impacts and threats identified in section 
4(a)(1).
    Information presented on impacts or threats should be specific to 
the species and should reasonably suggest that one or more of these 
factors may be operative threats that act or have acted on the species 
to the point that it may warrant protection under the ESA. Broad 
statements about generalized threats to the species, or identification 
of factors that could negatively impact a species, do not constitute 
substantial information indicating that listing may be warranted. We 
look for information indicating that not only is the particular species 
exposed to a factor, but that the species may be responding in a 
negative fashion; then we assess the potential significance of that 
negative response.
    Many petitions identify risk classifications made by 
nongovernmental organizations, such as the International Union on the 
Conservation of Nature (IUCN), the American Fisheries Society, or 
NatureServe, as evidence of extinction risk for a species. Risk 
classifications by other organizations or made under other Federal or 
state statutes may be informative, but such classification alone may 
not provide the rationale for a positive 90-day finding under the ESA. 
For example, as explained by NatureServe, their assessments of a 
species' conservation status do ``not constitute a recommendation by 
NatureServe for listing under the U.S. Endangered Species Act'' because 
NatureServe assessments ``have different criteria, evidence 
requirements, purposes and taxonomic coverage than government lists of 
endangered and threatened species, and therefore these two types of 
lists should not be expected to coincide'' (http://www.natureserve.org/prodServices/pdf/NatureServeStatusAssessmentsListing-Dec%202008.pdf). 
Additionally, species classifications under IUCN and the ESA are not 
equivalent; data standards, criteria used to evaluate species, and 
treatment of uncertainty are also not necessarily the same. Thus, when 
a petition cites such classifications, we will evaluate the source of 
information that the classification is based upon in light of the 
standards on extinction risk and impacts or threats discussed above.

Species Description and Taxonomy

    The petitioned population of dolphin (Sousa chinensis taiwanensis) 
is thought to be a subspecies of the Indo-Pacific humpback dolphin, 
Sousa chinensis. The Indo-Pacific humpback dolphin is a broadly 
distributed species within the genus Sousa, family Delphinidae, and 
order Cetacea. It is easy to distinguish from other dolphin species in 
its range, as 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 Taiwanese 
population also has a short dorsal fin with a wide base. However, 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 ca. 30 percent of body width and forms the base of an even 
smaller dorsal fin.
    In general, the Indo-Pacific humpback dolphin is medium-sized, with 
lengths up to 2.8 m, and weighs approximately 250-280 kg (Ross et al., 
1994). They form social groups of about 10 animals, but groups of up to 
30 animals have been documented (Jefferson et al., 1993).
    The petition identifies the Taiwanese humpback dolphin (Sousa 
chinensis taiwanensis) as eligible for listing under the ESA as a 
``subspecies'' of the Indo-Pacific humpback dolphin (Sousa chinensis). 
The taxonomy of the genus Sousa is unresolved and has historically been 
based on morphology, but genetic analyses have recently been used. 
Current taxonomic hypotheses identify Sousa chinensis as one of two 
(Jefferson et al., 2001), three (Rice, 1998), or four (Mendez et al., 
2013) species within the genus. Each species is associated with a 
unique geographic range, though the species' defined ranges vary 
depending on how many species are recognized. Rice (1998) recognizes 
Sousa teuzii in the eastern Atlantic, Sousa plumbea in the western 
Indo-Pacific, and Sousa chinensis in the eastern Indo-Pacific. Mendez 
et al. (2013) recently identified an as-yet unnamed potential new 
species in waters off of northern Australia. Currently, the 
International Union for Conservation of Nature (IUCN) and International 
Whaling Commission (IWC) Scientific Committee recognize only two 
species, Sousa chinensis in the Indo-Pacific, and Sousa teuzii in the 
eastern Atlantic. Most recently, Wang et al. (2015) revised the 
taxonomy of Sousa chinensis and concluded that the Taiwanese humpback 
dolphin (S. chinensis taiwanensis) is a valid subspecies. Specifically, 
Wang et al. (2015) expanded upon a previous study (Wang et al., 2008) 
regarding the pigmentation differences between the Taiwanese humpback 
dolphin and Indo-Pacific humpback dolphin populations inhabiting the 
Jiulong River and Pearl River estuaries from Hong Kong and Fujian in 
China. In the 2008 study, Wang et al. showed that the pigmentation of 
the Taiwanese population is significantly different from that of other 
populations within the taxon (Wang et al., 2008); however, the study 
did not examine the degree of differentiation for purposes of 
determining whether subspecies recognition was warranted. Thus, to 
remedy this oversight, Wang et al. (2015) examined the taxonomy of the 
Indo-Pacific humpback dolphin by comparing spotting densities on the 
bodies and dorsal fins of these adjacent populations and performing a 
discriminant analysis. The study determined that the differentiation in 
pigmentation patterns revealed nearly non-overlapping distributions 
between the dolphins from Taiwanese waters and those from the Jiulong 
River and Pearl River estuaries of mainland China (i.e., the nearest 
known populations). The study stated that the Taiwanese dolphins were 
clearly diagnosable from those of mainland China under the most 
commonly accepted 75 percent rule for subspecies delimitation, with 94 
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). As a result 
of this new information, the Taxonomy Committee of the Society for 
Marine Mammalogy officially revised its list of marine mammal taxonomy 
to include the Taiwanese humpback dolphin as a subspecies.
    While pigmentation of the Taiwanese population is significantly 
different from other populations within the taxon

[[Page 29518]]

(Wang et al., 2008; Wang et al., 2015), whether the pattern is adaptive 
or has genetic underpinnings is still uncertain. In other cetacean 
species, differences in pigmentation have been hypothesized to relate 
to several adaptive responses, allowing individuals to hide from 
predators, communicate with conspecifics (promoting group cohesion), 
and disorient and corral prey (Caro et al., 2011). However, the 
differences in Taiwanese humpback dolphin pigmentation may be a result 
of a genetic bottleneck from the small size of this population (less 
than 100 individuals) and it's possible that the Taiwanese humpback 
dolphin represents a single social and/or family group. Such small 
populations are more heavily influenced by genetic drift than large 
populations (Frankham, 1996). However, Wang et al. (2015) concluded 
that the differences between the Taiwanese dolphins and their nearest 
neighbors are not clinal, but are diagnosably different; the characters 
examined are not those that may be environmentally induced, but instead 
are likely a reflection of genetic and developmental differences. Thus, 
based on the information presented in the petition, which provides 
evidence that the Taiwanese humpback dolphin is indeed a subspecies 
(i.e., a listable entity under the ESA), we will proceed with our 
evaluation of the information in the petition to determine whether S. 
chinensis taiwanensis (referred henceforth as the Taiwanese humpback 
dolphin) may be warranted for listing throughout all or a significant 
portion of its range under the ESA.

Range, Distribution and Movement

    The Taiwanese humpback dolphin has an extremely small, restricted 
range, and is distributed throughout only 512 square km of coastal 
waters off western Taiwan, from estuarine waters of the Houlong and 
Jhonggang rivers in the north, to waters of Waishanding Jhou to the 
South (about 170 km linear distance), with the main concentration of 
the population 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., 2007b). Overall, 
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). 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).
    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 25-30 
meters, and thus deep water is thought to be the specific barrier 
limiting exchange with Chinese mainland populations (Jefferson and 
Karczmarski, 2001). The species as a whole experiences limited mobility 
and its restriction to shallow, near-shore estuarine habitats is a 
significant barrier to movement (Karczmarski et al., 1997; Hung and 
Jefferson, 2004).

Life History

    Little is known about the life history and reproduction of the 
Indo-Pacific humpback dolphin as a species, let alone the Taiwanese 
humpback dolphin as a subspecies. In some cases, comparison of the 
Taiwanese humpback dolphin with other populations may be appropriate, 
but one needs to be cautious about making these comparisons, as 
environmental factors such as food availability and habitat status may 
affect important rates of reproduction and generation time in different 
populations. A recent analysis of life history patterns for individuals 
in the Pearl River Estuary (PRE) population of mainland China may offer 
an appropriate proxy for understanding life history of the Taiwanese 
humpback dolphin population. Life history traits of the PRE population 
are similar to those of 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). 
Maximum longevity for the PRE and South African populations are 38 and 
40 years, respectively; thus, it can be assumed that the Taiwanese 
humpback dolphin experiences a similar life expectancy. In general, it 
is assumed that the population experiences long calving intervals, 
between 3 and 5 years (Jefferson et al., 2012), with gestation lasting 
approximately 10-12 months. It has been suggested that weaning may take 
up to 2 years, and strong female-calf association may last 3-4 years 
(Karczmarski et al., 1997; Karczmarski, 1999). Peak calving activity 
most likely occurs in the warmer months, but exact peak calving time 
may vary geographically (Jefferson et al., 2012). Age at sexual 
maturity is late, estimated between 12 and 14 years.

Analysis of Petition and Information Readily Available in NMFS Files

    The petition contains information on the Taiwanese humpback 
dolphin, including its taxonomy, description, geographic distribution, 
habitat, population status and trends, and factors contributing to the 
species' decline. According to the petition, all five causal factors in 
section 4(a)(1) of the ESA are adversely affecting the continued 
existence of the Taiwanese humpback dolphin: (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) inadequacy of 
existing regulatory mechanisms; and (E) other natural or manmade 
factors.
    In the following sections, we summarize and evaluate the 
information presented in the petition and in our files on the status of 
S. chinensis taiwanensis and the ESA section 4(a)(1) factors that may 
be affecting this species' risk of global extinction. Based on this 
evaluation, we determine whether a reasonable person would conclude 
that an endangered or threatened listing may be warranted for the 
species.

Status and Population Trends

    There have been two formal estimates of abundance for the Taiwanese 
humpback dolphin. The first is based on surveys conducted between 2002 
and 2004 using line transects to track and count animals, which 
resulted in an estimated population size of 99 individuals (coefficient 
of variation (CV) = 52 percent, 95 percent confidence interval = 37-
266) (Wang et al., 2007a). However, the 2007 international workshop on 
the conservation and research needs of the Taiwanese humpback dolphin 
population suggested that the true number of individuals may actually 
be lower than this estimate (Wang et al., 2007b). A re-analysis of 
population abundance conducted on data collected between 2007 and 2010 
used mark-recapture methods of photo identification, permitting higher-
precision measurements. Yearly population estimates from this study 
ranged from 54 to 74 individuals (CV varied from 4 percent to 13 
percent); these estimates were 25 percent to 45 percent lower than 
those from 2002-2004 (Wang et al., 2012). Jefferson (2000) estimated 
that mature individuals comprise 60 percent

[[Page 29519]]

of the population. Based on this proportion, and the largest estimate 
of population size from the most recent study (74 individuals), the 
Taiwanese humpback dolphin is most likely comprised of less than 45 
mature individuals.
    Given the extremely small and isolated nature of the population, 
even a small number of mortalities could potentially have significant 
negative population-level effects. For the Taiwanese humpback dolphin, 
Wang et al. (2012) measured survivorship for the population, which was 
used to determine a mortality rate of 1.5 percent (0.022) 
(Wang et al., 2012; Ara[uacute]jo et al., 2014). Carrying capacity for 
the Taiwanese humpback dolphin has been estimated at 250 individuals (a 
conservative estimate, higher than the highest point estimate of 
abundance from Wang (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. Additionally, a recent population viability analysis 
(PVA) suggests that the population is declining due to the synergistic 
effects of habitat degradation and detrimental fishing interactions 
(Ara[uacute]jo et al., 2014). Ara[uacute]jo et al., (2014) modeled 
population trajectory over 100 years using demographic factors combined 
with 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. 
Ultimately, strong evidence suggests that the population is small, and 
rates of decline are high, unsustainable, and potentially even 
underestimated. Further, it is clear that loss of only a single 
individual within the population per year would substantially reduce 
population growth rate (Dungan et al., 2011).

Analysis of ESA Section 4(a)(1) Factors

    While the petition presents information on each of the ESA section 
4(a)(1) factors, we find that the information presented, including 
information within our files, regarding habitat destruction and 
overutilization of the species as a result of fisheries interactions is 
substantial enough to make a determination that a reasonable person 
would conclude that this species may warrant listing as endangered or 
threatened based on these two factors alone. As such, we focus our 
discussion below on the evidence of habitat destruction and 
overutilization of the species, and present our evaluation of the 
information regarding these factors and their impact on the extinction 
risk of the Taiwanese humpback dolphin. The remaining factors discussed 
in the petition will be thoroughly evaluated in a comprehensive status 
review of the species.

Destruction, Modification, or Curtailment of the Species' Habitat or 
Range

    The Taiwanese humpback dolphin habitat best compares with that of 
populations located off the coast of mainland China. Taiwanese humpback 
dolphins are thought to be restricted to water <30 m deep, and most 
observed sightings have occurred in estuarine habitat with significant 
freshwater input (Wang et al., 2007a). The input of freshwater to S. 
chinensis taiwanensis 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.
    The petition states that the Taiwanese humpback dolphin is 
threatened by habitat destruction and modification and lists multiple 
causes, including reduction of freshwater outflows to estuaries, seabed 
reclamation, coastal development, and pollution (including chemical, 
biological, and noise pollution). Information in our files indicates 
that much of the preferred habitat of the Taiwanese humpback dolphin 
has been altered or may become altered. The near-shore marine and 
estuarine environment in Taiwan is intensively used by humans for 
fishing, sand extraction, land reclamation, transportation, and 
recreation, and is a recipient of massive quantities of effluent and 
runoff (Wang et al., 2007b). However, we do not have sufficient 
information to evaluate what effects many of the activities discussed 
in the petition (e.g., reduced freshwater flows, seabed reclamation) 
are having on the species' status. For example, while several of the 
rivers in western Taiwan have already been dammed or diverted for 
agricultural, municipal, or other purposes (Ross et al., 2010), there 
are no data or information in the petition or our files to indicate how 
reduced water flows to the estuaries are specifically impacting the 
Taiwanese humpback dolphins or their prey.
    In terms of pollution, we do have some information in our files 
indicating that these dolphins are exposed to toxic PCBs and are likely 
negatively affected through ingestion of contaminated prey. The 
Taiwanese humpback dolphin's exposure to land-based pollution and other 
threats is relatively high all along the central western coast of 
Taiwan, because these dolphins are thought to inhabit only a narrow 
strip of coastal habitat. Further, these dolphins have not been 
observed in waters deeper than 25-30 m and are typically sighted in 
waters 15 m deep and within 3 km from shore (Reeves et al., 2008). 
Given the restricted coastal range of the Taiwanese humpback dolphin 
and the extensive industrial and agricultural development in the 
region, food web contamination is likely, with sub-lethal and/or 
cumulative toxic effects having the potential to adversely impact small 
populations (Sheehy, 2010). By measuring PCB concentrations of known 
prey species, Riehl et al. (2011) constructed a bioaccumulation model 
to assess the risk PCBs may be posing to the Taiwanese humpback 
dolphins. Their results indicated that the Taiwanese humpback dolphins 
are at risk of immunotoxic effects of PCBs over their lifetime (Riehl 
et al., 2011). In addition, surveys of 97 Taiwanese humpback dolphins 
conducted from 2006 to 2010 showed that 73 percent had at least one 
type of skin lesion and that 49 percent of the surveyed dolphins were 
diseased (Yang et al., 2011). In another recent study documenting skin 
conditions of the Taiwanese humpback dolphin, 37 percent of individuals 
showed evidence of fungal disease, various lesions, ulcers, and 
nodules. The authors suggest that the high prevalence of compromised 
skin condition may be linked to high levels of environmental 
contamination (Yang et al., 2013). These data suggest the dolphins may 
have weakened immune systems and are consequently more susceptible to 
disease. Overall, evidence suggests that widespread habitat 
contamination may be leading to the bioaccumulation of toxins within 
Taiwanese humpback dolphin individuals; these toxins are known to 
compromise marine mammal reproduction and immune response, and may be 
negatively impacting the health and viability of the population.
    Overall, while we have insufficient information to evaluate some of 
the claims in the petition, we do have sufficient information to 
indicate that pollution is likely having a negative impact on the 
status of the Taiwanese humpback dolphin. Thus, we conclude that the 
information in the petition and in our files presents substantial

[[Page 29520]]

information that the Taiwanese humpback dolphin may warrant listing as 
threatened or endangered because of threats to its habitat.

Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    Information from the petition and in our files suggests that the 
primary threat to the Taiwanese humpback dolphin is overutilization as 
a result of commercial fisheries interactions and bycatch-related 
mortality. 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). 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). 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 (Ross et al., 2010; Slooten et al., 
2013). In a study exploring the impact of fisheries on the Taiwanese 
humpback dolphin, 59.2 percent of injuries (lethal and non-lethal) 
observed were confirmed to have originated from fisheries interactions 
(Slooten et al., 2013). Even in non-lethal interactions, injuries 
sustained due to encounters with fishing gear may lead to mortality via 
immunosuppression, stress, and malnutrition, although these effects are 
not easily measured (Dungan et al., 2011). In total, one third of 32 
photo-identified Taiwanese humpback dolphins had scars thought to have 
been caused by either collisions with ships or interactions with 
fishing gear (Wang et al., 2004). Further, while over 30 percent of the 
Taiwanese humpback dolphin population exhibits evidence of fisheries 
interactions, including wounds, scars, and entanglement (Wang et al., 
2007b; Slooten et al., 2013), this measurement likely underestimates 
the full extent of the threat, and the prevalence of internal damage 
from ingestion of fishing gear cannot be determined using current 
survey methods (Slooten et al., 2013). There are also two unpublished 
reports of dead, stranded Taiwanese humpback dolphins suspected to have 
died as a result of a fisheries interaction (Ross et al., 2010). 
Thousands of vessels fish with gillnets and trammel nets in waters used 
by humpback dolphins along the west coast of Taiwan. In fact, as of 
2009, a total of 6,318 motorized fishing vessels were operating inside 
the dolphins' habitat, corresponding to 32 vessels per km of coastline 
(Slooten et al., 2013). A recent progress report by Wang (2013) reports 
survey data from 2012 that documents individuals observed to have new 
injuries since last surveyed. Further, in an analysis of stranded 
individuals in the waters off Hong Kong, where coastal fishing activity 
is comparable to that off the west coast of Taiwan, the most commonly 
diagnosed causes of death were entanglement in fishing nets and vessel 
collision (Jefferson et al., 2006).
    In addition to direct mortality as a result of entanglement in 
fisheries gear, indirect effects of fishing activities may also be 
negatively impacting 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 caused by fisheries activity. In fact, 
individual Taiwanese humpback dolphins have shown evidence of 
disturbance from all of these effects (Slooten et al., 2013), and 
injuries from fishing gear and boat collisions can compromise the 
health of individuals and their capacity to adjust to other stressors, 
or cause death (Dungan et al., 2011).
    While the petition provides insufficient evidence to quantify the 
impact of fishing activities on the population of Taiwanese humpback 
dolphin, the annual removal of even a few individuals from such a small 
population due to fisheries interactions can disproportionally reduce 
population viability and could eventually lead to the extinction of the 
subspecies (Ross et al., 2010; Dungan et al., 2011; Slooten et al., 
2013). In fact, studies show that to ensure viability of the Taiwanese 
humpback dolphin population, mortality caused by fishing gear must be 
reduced to less than one individual every 7 years (Slooten et al., 
2013). Therefore, based on the information presented in the petition 
and in our files, we conclude that overutilization may be a threat 
negatively impacting the Taiwanese humpback dolphin, such that it is 
cause for concern and warrants further investigation to see if the 
species warrants listing as threatened or endangered under the ESA.
    While the petition identifies numerous other threats to the 
species, including diseases, the inadequacy of existing regulatory 
mechanisms, and other natural or manmade factors (e.g., climate change 
and ocean acidification), we find that the petition and information in 
our files suggests that impacts from habitat destruction and 
overutilization, in and of themselves, may be threats impacting the 
Taiwanese humpback dolphin to such a degree that raises concern that 
this species may be in danger of extinction throughout all or a 
significant portion of its range, or likely to become so in the 
foreseeable future. Thus, when we consider the Taiwanese humpback 
dolphin across its restricted range, based on the available information 
in the petition and in our files, its status is likely in decline, it 
continues to face numerous impacts to its habitat as well as pressure 
from fisheries interactions, and it has significant biological 
vulnerabilities and demographic risks (i.e., extremely low 
productivity; declining abundance; small, isolated population). 
Therefore, we find that the information in the petition and in our 
files would lead a reasonable person to conclude that S. chinensis 
taiwanensis may warrant listing as a threatened or endangered species 
throughout all or a significant portion of its range.

Petition Finding

    After reviewing the information contained in the petition, as well 
as information readily available in our files, and based on the above 
analysis, we conclude the petition presents substantial scientific 
information indicating the petitioned action of listing the Taiwanese 
humpback dolphin (S. chinensis taiwanensis) as a threatened or 
endangered species may be warranted. Therefore, in accordance with 
section 4(b)(3)(B) of the ESA and NMFS' implementing regulations (50 
CFR 424.14(b)(3)), we will commence a status review of the species. 
During the status review, we will determine whether the Taiwanese 
humpback dolphin is in danger of extinction (endangered) or likely to 
become so (threatened) throughout all or a significant portion of its 
range. We now initiate this review, and thus, S. chinensis taiwanensis 
is considered to be a candidate species (69 FR 19975; April 15, 2004). 
Within 12 months of the receipt of the petition (March 9, 2017), we 
will make a finding as to whether listing the Taiwanese humpback 
dolphin as an endangered or threatened species is warranted as required 
by section 4(b)(3)(B) of the ESA. If listing is found to be warranted, 
we will publish a proposed rule and solicit public comments before 
developing and publishing a final rule.

Information Solicited

    To ensure that the status review is based on the best available 
scientific and commercial data, we are soliciting

[[Page 29521]]

information on whether the Taiwanese humpback dolphin is endangered or 
threatened. Specifically, we are soliciting information in the 
following areas: (1) Historical and current distribution and abundance 
of the species throughout its range; (2) historical and current 
population trends; (3) life history and habitat requirements; (4) 
population structure information, such as genetics analyses of the 
species; (5) past, current and future threats, including any current or 
planned activities that may adversely impact the species; (6) ongoing 
or planned efforts to protect and restore the species and its habitat; 
and (7) management, regulatory, and enforcement information. We request 
that all information be accompanied by: (1) Supporting documentation 
such as maps, bibliographic references, or reprints of pertinent 
publications; and (2) the submitter's name, address, and any 
association, institution, or business that the person represents.

References Cited

    A complete list of references is available upon request to the 
Office of Protected Resources (see ADDRESSES).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: May 4, 2016.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
[FR Doc. 2016-11014 Filed 5-11-16; 8:45 am]
 BILLING CODE 3510-22-P