Endangered and Threatened Wildlife and Plants; Notice of 12-Month Finding on Petition To List the Smooth Hammerhead Shark as Threatened or Endangered Under the Endangered Species Act
Federal Register, Volume 81 Issue 124 (Tuesday, June 28, 2016)
Federal Register Volume 81, Number 124 (Tuesday, June 28, 2016)
Notices
Pages 41934-41958
From the Federal Register Online via the Government Publishing Office www.gpo.gov
FR Doc No: 2016-15200
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
Docket No. 150506425-6516-02
RIN 0648-XD941
Endangered and Threatened Wildlife and Plants; Notice of 12-Month Finding on Petition To List the Smooth Hammerhead Shark as Threatened or Endangered Under the Endangered Species Act
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of 12-month finding and availability of status review document.
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SUMMARY: We, NMFS, announce a 12-month finding on a petition to list the smooth hammerhead shark (Sphyrna zygaena) as threatened or endangered under the Endangered Species Act (ESA). We have completed a comprehensive status review of the smooth hammerhead shark in response to this petition. Based on the best scientific and commercial information available, including the status review report (Miller 2016), we have determined that the species does not warrant listing at this time. We conclude that the smooth hammerhead shark is not currently in danger of extinction throughout all or a significant portion of its range and is not likely to become so within the foreseeable future.
DATES: This finding was made on June 28, 2016.
ADDRESSES: The status review report for the smooth hammerhead shark is available electronically at: http://www.fisheries.noaa.gov/pr/species/fish/smooth-hammerhead-shark.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: Smooth Hammerhead Shark 12-month Finding.
FOR FURTHER INFORMATION CONTACT: Maggie Miller, NMFS, Office of Protected Resources, (301) 427-8403.
SUPPLEMENTARY INFORMATION:
Background
On April 27, 2015, we received a petition from Defenders of Wildlife to list the smooth hammerhead shark (Sphyrna zygaena) as threatened or endangered under the ESA throughout its entire range, or, as an alternative, to list any identified Distinct Population Segment (DPS) as threatened or endangered. The petitioners also requested that critical habitat be designated for the smooth hammerhead under the ESA. In the case that the species does not warrant listing under the ESA, the petition requested that the species be listed based on its similarity of appearance to the listed DPSs of the scalloped hammerhead shark (Sphyrna lewini). On August 11, 2015, we published a positive 90-
day finding (80 FR 48053) announcing that the petition presented substantial scientific or commercial information indicating the petitioned action of listing the species may be warranted and explained the basis for that finding. We also announced the initiation of a status review of the species, as required by Section 4(b)(3)(a) of the ESA, and requested information to inform the agency's decision on whether the species warranted listing as endangered or threatened under the ESA.
Listing Species Under the Endangered Species Act
We are responsible for determining whether smooth hammerhead sharks are threatened or endangered under the ESA (16 U.S.C. 1531 et seq.). To make this determination, we first consider whether a group of organisms constitutes a ``species'' 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'' is not currently at risk of extinction, but is likely to become so in the foreseeable future. The 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 one or a combination 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 species. In evaluating the efficacy of existing domestic protective efforts, we rely on the Services' joint Policy on Evaluation of Conservation Efforts When Making Listing Decisions (``PECE''; 68 FR 15100; March 28, 2003) for any conservation efforts that have not been implemented, or have been implemented but not yet demonstrated effectiveness.
Status Review
The status review for the smooth hammerhead shark was conducted by a NMFS biologist in the Office of
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Protected Resources (Miller 2016). The status review examined the entire species' status throughout its range and also evaluated if any portion of the smooth hammerhead shark's range was significant as defined by the Services Significant Portion of its Range (SPR) Policy (79 FR 37578; July 1, 2014).
In order to complete the status review, information was compiled on the species' biology, ecology, life history, threats, and status from information contained in the petition, our files, a comprehensive literature search, and consultation with experts. We also considered information submitted by the public in response to our petition finding. In assessing extinction risk of the smooth hammerhead shark, we considered the demographic viability factors developed by McElhany et al. (2000). The approach of considering demographic risk factors to help frame the consideration of extinction risk has been used in many of our status reviews, including for Pacific salmonids, Pacific hake, walleye pollock, Pacific cod, Puget Sound rockfishes, Pacific herring, scalloped and great hammerhead sharks, and black abalone (see http://www.nmfs.noaa.gov/pr/species/ for links to these reviews). In this approach, the collective condition of individual populations is considered at the species level according to four viable population descriptors: Abundance, growth rate/productivity, spatial structure/
connectivity, and diversity. These viable population descriptors reflect concepts that are well-founded in conservation biology and that individually and collectively provide strong indicators of extinction risk (NMFS 2015b).
The 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 status review report was peer reviewed by three independent specialists selected from the academic and scientific community, with expertise in shark biology, conservation and management, and knowledge of smooth hammerhead sharks. The peer reviewers were asked to evaluate the adequacy, appropriateness, and application of data used in the status review, including the extinction risk analysis. All peer reviewer comments were addressed prior to dissemination of the final status review report and publication of this determination.
We subsequently reviewed the status review report, its cited references, and peer review comments, and believe the status review report, upon which this 12-month finding is based, provides the best available scientific and commercial information on the smooth hammerhead shark. Much of the information discussed below on smooth hammerhead shark biology, distribution, abundance, threats, and extinction risk is attributable to the status review report. However, in making the 12-month finding determination, we have independently applied the statutory provisions of the ESA, including evaluation of the factors set forth in Section 4(a)(1)(A)-(E) and our regulations regarding listing determinations. The status review report is available on our Web site (see ADDRESSES section) and the peer review report is available at http://www.cio.noaa.gov/services_programs/prplans/PRsummaries.html. Below is a summary of the information from the report and our analysis of the status of the smooth hammerhead shark. Further details can be found in Miller (2016).
Description of the Petitioned Species
Taxonomy and Species Description
All hammerhead sharks belong to the family Sphyrnidae and are classified as ground sharks (Order Carcharhiniformes). Most hammerheads belong to the Genus Sphyrna with one exception, the winghead shark (Eusphyra blochii), which is the sole species in the Genus Eusphyra. The smooth hammerhead was first described in 1758 by Karl Linnaeus and named Squalus zygaena; however, this name was later changed to the current scientific species name of Sphyrna zygaena (Linneaus 1758) (Bester n.d.).
The hammerhead sharks are recognized by their laterally expanded head that resembles a hammer (hence the common name ``hammerhead''). In comparison to the other hammerhead sharks, the head of the smooth hammerhead shark has a scalloped appearance but a rounded un-notched anterior margin (which helps to distinguish it from scalloped hammerhead sharks) and depressions opposite each nostril. The smooth hammerhead also has a ventrally located and strongly arched mouth with smooth or slightly serrated teeth (Compagno 1984). The body of the shark is fusiform, lacks a mid-dorsal ridge, and has a moderately tall and hooked first dorsal fin and a lower second dorsal fin that is shorter than the notched anal fin (Compagno 1984; Bester n.d.). The color of the smooth hammerhead shark ranges from a dark olive to greyish-brown and fades into a white underside, which is different than most other hammerhead species whose colors are commonly brown (Bester n.d.).
Range and Habitat Use
The smooth hammerhead shark is a circumglobal species, found worldwide in temperate to tropical waters between 59 degN. and 55 degS. latitudes (CITES 2013). It is thought to be the hammerhead species most tolerant of temperate waters (Compagno 1984). In the northwestern Atlantic Ocean, the range of the smooth hammerhead shark extends from Nova Scotia, Canada to Florida, and partly into the Caribbean; however, the species is said to be rare in Canadian waters and only found offshore in the Gulf Stream (Fisheries and Oceans Canada 2010). Additionally, its presence off the Caribbean Islands cannot be confirmed, although these waters are noted to be part of its range in Compagno (1984). In the southwestern Atlantic, the smooth hammerhead shark range extends from Brazil to southern Argentina, and in the eastern Atlantic Ocean, smooth hammerhead sharks can be found from the British Isles to equatorial West Africa and throughout the Mediterranean Sea (Compagno 1984; Bester n.d).
In the Indian Ocean, the shark is found off the coasts of South Africa, within the Persian Gulf, along the southern coast of India, Sri Lanka, and off Indonesia, and along the western and southern coasts of Australia. Its range in the western and central Pacific extends from Japan to Vietnam, including the southeast coast of Australia and waters off New Zealand, the Hawaiian Islands and American Samoa. In the northeastern Pacific, the smooth hammerhead shark range extends from northern California to the Nayarit state of Mexico, and in the southeastern Pacific, the species can be found from Panama to Chile, but is generally rare in Chilean waters (Brito 2004).
The smooth hammerhead shark is a coastal-pelagic and semi-oceanic species and generally occurs close inshore and in shallow waters, most commonly in depths of up to 20 m (CITES 2013). However, the species may also be found over continental and insular shelves to offshore areas in depths as great as 200 m (Compagno 1984; Ebert et al. 2013; Bester n.d.). Smooth hammerhead sharks are highly mobile and may undergo seasonal migrations (toward cooler waters in the summer and the reverse in the winter), with juveniles (of up to 1.5 m in length) occasionally forming large aggregations during these migrations (Compagno 1984; Diemer et al. 2011; Ebert et al. 2013; Bester n.d.).
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Adult smooth hammerhead sharks, on the other hand, are generally solitary (Compagno 1984). Based on available tagging data, the species is able to travel significant distances, with various studies showing estimates of total distance travelled of around 919 km (Kohler and Turner 2001), more than 1,609 km (SWFSC 2015), and around 2,220 km (Clarke et al. 2015).
Diet and Feeding
The smooth hammerhead shark is a high trophic level predator (trophic level = 4.2; Corteacutes (1999)) and opportunistic feeder that consumes a variety of teleosts, small sharks (including its own species), dolphins, skates and stingrays, sea snakes, crustaceans, and cephalopods (Nair and James 1971; Compagno 1984; Bornatowski et al. 2007; Masunaga et al. 2009; Rogers et al. 2012; Galvan-Magana et al. 2013; Bornatowski et al. 2014; Sucunza et al. 2015). Skates and stingrays, in particular, tend to comprise the majority of the species' diet in inshore locations (Nair and James 1971; Bester n.d.), whereas in coastal and shelf waters, cephalopods appear to be an important prey item (Bornatowski et al. 2007; Bornatowski et al. 2014).
Growth and Reproduction
The general life history characteristics of the smooth hammerhead shark are that of a long-lived, slow-growing, and late maturing species. The average size of a smooth hammerhead shark ranges between 2.5-3.5 m in length, but individuals can reach maximum lengths of 5 m and weights of 880 pounds (400 kg) (CITES 2013; Bester n.d.). Based on observed and estimated sizes of smooth hammerhead sharks from both the Atlantic and Pacific oceans, females appear to reach sexual maturity between 250 cm and 290 cm total length (TL). Males are considered sexually mature at smaller sizes than females, with estimates of 210-
250 cm TL from the Atlantic and 250-260 cm TL in the western Pacific. More recent data from the eastern Pacific (specifically the Gulf of California) estimate much smaller maturity sizes for smooth hammerhead sharks, with 50 percent of females and males of the population maturing at 200 cm and 194 cm TL, respectively (Nava Nava and Fernando Marquez-
Farias 2014). Longevity of the species is unknown but thought to be at least 20 years (Bester n.d.), with female and male smooth hammerhead sharks aged up to 18 years and 21 years, respectively, from the eastern equatorial Atlantic Ocean (Coelho et al. 2011).
The smooth hammerhead shark is viviparous (i.e., give birth to live young), with a gestation period of 10-11 months (White et al. 2006) and an assumed annual reproductive periodicity; however this has yet to be verified (Clarke et al. 2015). Possible pupping grounds and nursery areas for this species (based on the presence of pregnant females, neonates, and juveniles) include the Gulf of California, Gulf of Guinea, Strait of Sicily, coastal and inshore waters off Baja California, Venezuela, southern Brazil, Uruguay, Morocco, the southern and eastern cape of South Africa, Kenya (including Ungwana Bay), and New Zealand (Sadowsky 1965; Castro and Mejuto 1995; Buencuerpo et al. 1998; Arocha et al. 2002; Celona and Maddalena 2005; Costa and Chaves 2006; Bizzarro et al. 2009; Cartamil et al. 2011; Coelho et al. 2011; Diemer et al. 2011; CITES 2013; Kyalo and Stephen 2013; Bornatowski et al. 2014; Nava Nava and Fernando Marquez-Farias 2014). Litter sizes range from around 20 to 50 live pups, with an average of around 33 pups, and length at birth is estimated to be between 49-64 cm. The smooth hammerhead shark is estimated to grow an average of 25 cm per year over the first 4 years of its life before slowing down later in its life (Coelho et al. 2011).
Demography
Although there are very few age/growth studies, based on the best available data, smooth hammerhead sharks exhibit life-history traits and population parameters that place the species towards the faster growing end along the ``fast-slow'' continuum of population parameters that have been calculated for 38 species of sharks by Corteacutes (2002, Appendix 2). In an Ecological Risk Assessment study of 20 species caught in Atlantic pelagic fisheries, Corteacutes et al. (2012) found that the smooth hammerhead shark ranked among the most productive species (with the 4th highest productivity rate; r = 0.225) and had one of the lowest vulnerabilities to pelagic longline fisheries. Based on these estimates, smooth hammerhead sharks can be characterized as having ``medium'' productivity (based on categorizations in Musick (1999)), with demographic parameters that provide the species with moderate resilience to exploitation.
Population Structure
Due to sampling constraints, very few studies have examined the population structure of the smooth hammerhead shark. Using mitochondrial DNA (which is maternally inherited) Naylor et al. (2012) found only a single cluster of smooth hammerhead sharks (in other words, no evidence to suggest matrilineal genetic partitioning of the species). This analysis, however, suffered from low sample size, based on only 16 specimens, but covered the longitudinal distribution of the species (Naylor et al. 2012). In contrast, Testerman (2014) analyzed both mitochondrial control region sequences (mtCR; n=303, 1,090 base pair) and 15 nuclear microsatellite loci (n=332) from smooth hammerhead sharks collected from 8 regional areas: Western North Atlantic (n=21); western South Atlantic (n=55); western Indian Ocean (n=63); western South Pacific (n=44); western North Pacific (n=11); eastern North Pacific (n=55); eastern Tropical Pacific (n=15); and eastern South Pacific (n=6). Results from the analysis of mitochondrial DNA indicated significant genetic partitioning, with no sharing of haplotypes, between the Atlantic and Indo-Pacific basins (mtCR phisST=0.8159) (Testerman 2014). Analysis of the nuclear DNA also showed significant genetic structure between ocean basins (nuclear FST=0.0495), with the Atlantic and Indo-Pacific considered to comprise two genetically distinct populations (Testerman 2014). However, additional studies are needed to further refine the population structure of the smooth hammerhead shark and confirm the above results, including, as Testerman (2014) suggests, using samples from individual smooth hammerhead sharks of known size class and gender.
Species Finding
Based on the best available scientific and commercial information described above, we determined that Sphyrna zygaena is a taxonomically-
distinct species and, therefore, meets the definition of ``species'' pursuant to section 3 of the ESA. Below, we evaluate whether Sphyrna zygaena warrants listing under the ESA as an endangered or threatened species throughout all or a significant portion of its range.
Assessment of Extinction Risk
The ESA (Section 3) defines endangered species as ``any species which is in danger of extinction throughout all or a significant portion of its range.'' Threatened species are ``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 any formal policy guidance about how to interpret the definitions of threatened and endangered. For the term ``foreseeable future,'' we define it as the timeframe over which identified threats
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could be reliably predicted to impact the biological status of the species. For the assessment of extinction risk for smooth hammerhead sharks, the ``foreseeable future'' was considered to extend out several decades. Given the species' life history traits, with longevity estimated to be greater than 20 years, maturity at around 8 years, and generation time at around 13 years, it would likely take several decades (i.e., multiple generations) for any recent management actions to be realized and reflected in population abundance indices (e.g., impact of declining shark fin trade). Furthermore, as the main potential operative threat to the species is overutilization by commercial and artisanal fisheries (discussed below), this timeframe (i.e., several decades) would allow for reliable predictions regarding the impact of current levels of fishery-related mortality on the biological status of the species. As depicted in the very limited available catch per unit effort (CPUE) time-series data, trends in the species' abundance can manifest within this time horizon.
In evaluating the level of risk faced by a species in deciding whether the species is threatened or endangered, 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 smooth hammerhead shark and considered alongside the information on threats to the species, including those related to the factors specified by the ESA Section 4(a)(1)(A)-(E). Specific methods on the demographic risk analysis can be found in the status review report, but each demographic factor was ultimately assigned one of three qualitatively-described levels of risk: ``very low or low risk,'' ``medium risk,'' or ``high risk'' (Miller 2016). The information from this demographic risk analysis in conjunction with the available information on threats (summarized below) was interpreted using professional judgement to determine an overall risk of extinction for S. zygaena. Because species-specific information is insufficient, a reliable, quantitative model of extinction risk could not be conducted as this time. The qualitative reference levels of ``low risk,'' ``moderate risk'' and ``high risk'' were used to describe the overall assessment of extinction risk, with detailed definitions of these risk levels found in the status review report (Miller 2016).
Evaluation of Demographic Risks
Abundance
Current and accurate abundance estimates are unavailable for the smooth hammerhead shark. With respect to general trends in population abundance, multiple studies indicate that smooth hammerhead sharks may have experienced population declines over the past few decades, although these studies suffer from very low sample sizes and a lack of reliable data due to the scarcity of the smooth hammerhead sharks in the fisheries data. Catch records also generally fail to differentiate between the Sphyrna species. As such, many of the available studies examining abundance trends have, instead, looked at the entire hammerhead shark complex (scalloped, smooth, and great hammerhead sharks combined). However, attributing the observed declines from these studies to the smooth hammerhead shark population could be erroneous, especially given the distribution and proportion of S. zygaena compared to other hammerhead species. As smooth hammerhead sharks tend to occur more frequently in temperate waters compared to other Sphyrna species, they are likely to be impacted by different fisheries, which may explain the large differences in the proportions that S. zygaena comprise in the available commercial and artisanal ``hammerhead'' catch. In fact, based on the available information (discussed in more detail in the section Overutilization for Commercial, Recreational, Scientific or Educational Purposes), the proportion of smooth hammerhead sharks compared to the other hammerhead species in the fisheries data ranges from 4.60 mug/g and mercury concentration in liver samples averaged 35.89 3.58 mug/g. Similarly, Garciacutea-Hernaacutendez et al. (2007) found high concentrations of mercury in tissues of four smooth hammerhead sharks (size range: 163-280 cm TL) from the Gulf of California, Mexico, with mean mercury concentration in muscle tissue of 8.25 9.05 mug/g. In contrast, Escobar-Sanchez et al. (2010) tested muscle tissue of 37 smooth hammerhead sharks from the Mexican Pacific (Baja California Sur, Mexico; size range: >55-184 cm TL) and found mercury concentrations were below the maximum safety limit of 1 mug/g (average = 0.73 mug/
g; median = 0.10 mug/g). Out of the 37 studied sharks, only one shark had a mercury concentration that exceeded the recommended limit (1.93 mug/g). Likewise, Maz-Courrau et al. (2012) also found ``safe'' concentrations of mercury in smooth hammerhead sharks from the Baja California peninsula. Analysis of muscle tissue samples from 31 smooth hammerhead sharks (mean size = 114 cm TL 19.2) showed an average mercury concentration of 0.98 0.92 mug/g dry weight (range: 0.24-2.8 mug/g). The authors also tested mercury concentrations in four prey species of Pacific sharks (mackerel Scomber japonicus, lantern fish Symbolophorus evermanni, pelagic red crab Pleuroncodes planipes, and giant squid Dosidicus gigas) and found that D. gigas, a common prey item for smooth hammerhead sharks (see Diet and Feeding), had the lowest mercury concentration (0.12 0.05 mug/g). The authors suggest that the transfer of mercury to smooth hammerhead sharks is unlikely to come from feeding on cephalopods; however, these results may very well explain the observed low levels of mercury in smooth hammerhead shark tissues (i.e., because these sharks prefer to feed on cephalopods, bioaccumulation of mercury in tissues would likely be low).
In Atlantic waters, Marsico et al. (2007) also found that smooth hammerhead sharks had relatively low levels of mercury concentrations (in comparison to the recommended 1 mug/g human consumption limit). Based on muscle tissue samples from 5 smooth hammerhead sharks caught off the coast of Santa Catarina, Brazil, average mercury concentration was 0.443 0.299 mug/g with a range of 0.015-0.704 mug/
g. In Indo-Pacific waters, the only information on S. zygaena mercury bioaccumulation is an analysis of muscle tissue from a single smooth hammerhead that was caught off Port Stephens, NSW, Australia (Paul et al. 2003). The smooth hammerhead shark was 232 cm in length and had a muscle tissue mercury concentration of 1.9 mug/g.
Based on the above information, it appears that mercury concentrations may correlate with size of the smooth hammerhead shark, with larger sharks, such as those examined in the Paul et al. (2003), Storelli et al. (2003), and Garciacutea-Hernaacutendez et al. (2007) studies, containing higher mercury concentrations. However, analyses examining this very relationship show conflicting results (Escobar-Sanchez et al. (2010)--no correlation; Maz-Courrau et al. (2012)--significant correlation). Furthermore, the effect of these and other mercury concentrations in smooth hammerhead shark populations, and potential risk to the viability of the species, remains unknown. It is hypothesized that these apex predators can actually handle higher body burdens of anthropogenic toxins due to the large size of their livers which ``provides a greater ability to eliminate organic toxicants than in other fishes'' (Storelli et al. 2003) or may even be able to limit their exposure by sensing and avoiding areas of high toxins (like during K. brevis red tide blooms) (Flewelling et al. 2010). Currently, the impact of toxin and metal bioaccumulation in smooth hammerhead shark populations is unknown. In fact, there is no information on the lethal concentration limits of toxins or metals in smooth hammerhead sharks, or evidence to suggest that current concentrations of environmental pollutants are causing detrimental physiological effects to the point where the species may be at an increased risk of extinction. As such, at this time, the best available information does not indicate that the present bioaccumulation rates and concentrations of environmental pollutants in the tissues of smooth hammerhead sharks are threats significantly contributing to the species' risk of extinction throughout its global range, now or in the foreseeable future.
Threats Assessment Summary
Based on the best available information summarized above and discussed in more detail in the status review (Miller 2016), none of the ESA Section 4(a)(1) factors, either alone or in combination with each other, are identified as threats significantly contributing to the extinction risk of the species. While overutilization poses the largest potential threat to the species, based on the best available data throughout the species' range, present fishery-related mortality rates of the shark do not appear to be affecting the species' demographics to such a degree that cause it to be strongly influenced by stochastic or depensatory processes or on a trajectory toward this point.
In the Atlantic Ocean, where species-specific data is available, the regional and local information indicates that smooth hammerhead sharks tend to be a rare occurrence, observed only sporadically in the fisheries data and in low numbers. In the northwest Atlantic, harvest and bycatch of the species is very low and strong management measures are in place to prevent overfishing of the species. In the southwest Atlantic, while the majority of the catch appears to be juveniles, smooth hammerhead sharks are generally harvested at low levels and comprise a small proportion of the fisheries catch. In the temperate waters of the Mediterranean Sea, smooth hammerhead sharks were historically a common occurrence. However, with the intense coastal fishing and the expansion of the tuna and swordfish longline and drift net fisheries in the 1970s, smooth hammerhead sharks have been fished almost to extinction in the Mediterranean Sea. Fishing pressure remains high in this portion of the species' range, which will likely result in additional fishing mortality and continued declines in the population. However, the Mediterranean comprises only a small portion of the species' range, and given the lack of trends or evidence of significant declines elsewhere in the Atlantic, the available data do not indicate that the overutilization and depletion of the Mediterranean population has significantly affected other S. zygaena populations in the Atlantic.
Similarly, in the Indian and Pacific Oceans, the available data, albeit severely lacking, depict a species that is not regularly caught, or caught in large numbers, by fisheries operating in these regions. The majority of fishing effort, particularly in the Indian Ocean, tends to be concentrated in more tropical waters, thereby decreasing the threat of overutilization by these fisheries on the more temperately-
distributed smooth hammerhead shark. However, in the Western Pacific, there are a number of fisheries operating within the temperate
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portions of this region (e.g., off Japan, Australia, New Zealand) that report regular catches of smooth hammerhead sharks. Based on the available data from these fisheries, including catch time series and CPUE data, no clear trends were found that would suggest overutilization is a significant threat to the species. In the Eastern Pacific, artisanal fisheries are responsible for the majority of the smooth hammerhead catch, and land primarily juveniles of the species. However, based on preliminary information on catch trends (primarily from Peru and Ecuador), there is no evidence to suggest that this level of utilization has or is significantly impacting recruitment to the population.
Furthermore, the number of regulatory and management measures, including hammerhead retention bans and finning regulations, as well as the creation of shark sanctuaries, has been on the rise in recent years. These regulations are aimed at decreasing the amount of sharks being landed or finned just for the shark fin trade and work to dis-
incentivize fishermen from targeting vulnerable shark species. Additionally, with the CITES Appendix II listing, mechanisms are also now in place to monitor and control international trade in the species and ensure that this trade is not detrimental to the survival of the species in the wild. Already it appears that the demand for shark fins is on the decline. While it is unclear how effective these regulations will be in ultimately reducing fishing mortality rates for the smooth hammerhead shark (given their high at-vessel mortality rates), it is likely to decrease fishing pressure on the species, particularly in those fisheries that target the species and by those fishermen that illegally fish for the species solely for the shark fin trade.
Overall, while there is a clear need for further research and data collection on smooth hammerhead sharks, the best available information at this time does not indicate that any of the ESA Section 4(a)(1) factors, or a combination of these factors, are significantly contributing to the extinction risk of the species throughout its global range, now or in the foreseeable future.
Overall Risk Summary
While the species' life history characteristics increase its inherent vulnerability to depletion, and likely contributed to past population declines of varying magnitudes, the best available information suggests that present demographic risks are low. Smooth hammerhead sharks continue to be exploited throughout their range, particularly juveniles of the species. While it is universally acknowledged that information is severely lacking for the species, including basic catch and effort data from throughout the species' range, global, regional, and local population size estimates, abundance trends, life history parameters (particularly from the Pacific and Indian Oceans), and distribution information, the best available data do not indicate that present fishing levels and associated mortality, habitat modification, disease, predation, environmental pollutant levels, or a combination of these factors, are causing declines in the species to such a point that the species is at risk of extinction or likely to become so in the foreseeable future. Thus, guided by the results from the demographic risk analysis and threats assessment, we conclude that the smooth hammerhead shark is currently at a low risk of extinction throughout all of its range.
Significant Portion of Its Range
The definitions of both ``threatened'' and ``endangered'' under the ESA contain the term ``significant portion of its range'' as an area smaller than the entire range of the species which must be considered when evaluating a species risk of extinction. On July 1, 2014, the Services published the SPR Policy, which provides our interpretation and application for how to evaluate whether a species is in danger of extinction, or likely to become so in the foreseeable future, in a ``significant portion of its range'' (79 FR 37578; July 1, 2014).
Because we found that the smooth hammerhead shark is at a low risk of extinction throughout its range, under the SPR Policy, we must go on to evaluate whether the species is in danger of extinction, or likely to become so in the foreseeable future, in a ``significant portion of its range.'' The SPR Policy explains that it is necessary to fully evaluate a particular portion for potential listing under the ``significant portion of its range'' authority only if substantial information indicates that the members of the species in a particular area are likely both to meet the test for biological significance and to be currently endangered or threatened in that area. Making this preliminary determination triggers a need for further review, but does not prejudge whether the portion actually meets these standards such that the species should be listed. To identify only those portions that warrant further consideration, we will determine whether there is substantial information indicating that (1) the portions may be significant and (2) the species may be in danger of extinction in those portions or likely to become so within the foreseeable future. We emphasize that answering these questions in the affirmative is not a determination that the species is endangered or threatened throughout a significant portion of its range--rather, it is a step in determining whether a more detailed analysis of the issue is required (79 FR 37578, at 37586; July 1, 2014).
Thus, the preliminary determination that a portion may be both significant and endangered or threatened merely requires us to engage in a more detailed analysis to determine whether the standards are actually met (79 FR 37578, at 37587). Unless both standards are met, listing is not warranted. The SPR policy further explains that, depending on the particular facts of each situation, we may find it is more efficient to address the significance issue first, but in other cases it will make more sense to examine the status of the species in the potentially significant portions first. Whichever question is asked first, an affirmative answer is required to proceed to the second question. Id. ``If we determine that a portion of the range is not `significant,' we will not need to determine whether the species is endangered or threatened there; if we determine that the species is not endangered or threatened in a portion of its range, we will not need to determine if that portion is `significant' '' Id. Thus, if the answer to the first question is negative--whether that regards the significance question or the status question--then the analysis concludes and listing is not warranted.
As defined in the SPR Policy, a portion of a species' range is ``significant'' ``if the species is not currently endangered or threatened throughout its range, but the portion's contribution to the viability of the species is so important that, without the members in that portion, the species would be in danger of extinction, or likely to become so in the foreseeable future, throughout all of its range'' (79 FR 37578, at 37609). For purposes of the SPR Policy, ``the range of a species is considered to be the general geographical area within which that species can be found at the time FWS or NMFS makes any particular status determination. This range includes those areas used throughout all or part of the species' life cycle, even if they are not used regularly (e.g., seasonal habitats). Lost historical range is relevant to the analysis of the status of the species, but it cannot constitute a significant portion of a species' range'' Id.
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Applying the SPR policy to the smooth hammerhead shark, we first evaluated whether there is substantial information indicating that any portions of the species' range may be significant. After a review of the best available information, we find that the data do not indicate any portion of the smooth hammerhead shark's range as being more significant than another. Smooth hammerhead sharks are highly mobile, with a global distribution, and very few restrictions governing their movements. While the Mediterranean region was recognized as a portion of the species' range in which it is likely at risk of extinction due to threats of overutilization, the Mediterranean represents only a small portion of the global range of the smooth hammerhead sharks. Furthermore, there is no indication that loss of that part of the species' range would constitute a moderate or high extinction risk to the global species, now or in the foreseeable future. As was mentioned previously, the available population and trend data do not indicate that the depletion of the Mediterranean population has significantly affected other S. zygaena populations. Thus, the Mediterranean would not qualify as ``significant'' under the SPR Policy.
Likewise, there is no substantial evidence to indicate that the loss of genetic diversity from one portion of the species' range (such as loss of an ocean basin population) would result in the remaining populations lacking enough genetic diversity to allow for adaptations to changing environmental conditions. Similarly, there is no information to suggest that loss of any portion would severely fragment and isolate the species to the point where individuals would be precluded from moving to suitable habitats or have an increased vulnerability to threats. In other words, loss of any portion of its range would not likely isolate the species to the point where the species would be at risk of extinction from demographic processes, or likely to be so in the foreseeable future, throughout all of its range.
Areas exhibiting source-sink dynamics, which could affect the survival of the species, were not evident in any part of the smooth hammerhead sharks' range. There is also no evidence of a portion that encompasses aspects that are important to specific life history events, but another portion that does not, where loss of the former portion would severely impact the growth, reproduction, or survival of the entire species, now or in the foreseeable future. In fact, potential pupping grounds and nursery areas for the species were identified in all three major ocean basins. In other words, the viability of the species does not appear to depend on the productivity of the population or the environmental characteristics in any one portion.
It is important to note that the overall distribution of the smooth hammerhead shark is still uncertain, considered to be generally patchy but also unknown in large areas, such as the Indian Ocean. As better data become available, the species distribution (and potentially significant portions of its range) will become better resolved; however, at this time, there is no evidence to suggest that any specific portion of the species' range has increased importance over another with respect to the species' survival. As such, we did not identify any portions of the species' range that meet both criteria under the SPR Policy (i.e., the portion is biologically significant and the species may be in danger of extinction in that portion, or likely to become so within the foreseeable future). Therefore, listing is not warranted under the SPR policy.
Distinct Population Segment Analysis
The ESA's definition of ``species'' includes ``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.'' Our DPS Policy clarifies our 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). In the 90-day finding addressing the smooth hammerhead shark petition, we stated that we would consider whether the populations requested by the petitioner qualify as DPSs pursuant to our DPS Policy and warrant listing (80 FR 48052; August 11, 2015).
When identifying a DPS, our DPS policy stipulates two elements that must be considered: (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. In terms of discreteness, the DPS policy states that a population of a vertebrate species may be considered discrete if it satisfies either one of the following conditions: (1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors (quantitative measures of genetic or morphological discontinuity may provide evidence of this separation) or (2) it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of Section 4(a)(1)(D) of the ESA. If a population segment is considered discrete under one or more of the above conditions, then its biological and ecological significance is considered. Significance under the DPS policy is evaluated in terms of the importance of the population segment to the overall welfare of the species. Some of the considerations that can be used to determine a discrete population segment's significance to the taxon as a whole include: (1) Persistence of the population segment in an unusual or unique ecological setting; (2) evidence that loss of the population segment would result in a significant gap in the range of the taxon; (3) evidence that the discrete population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historic range; or (4) evidence that the population segment differs markedly from other populations of the species in its genetic characteristics.
The petition states that the smooth hammerhead shark is comprised of five DPSs: Northeast Atlantic and Mediterranean Sea, Northwest Atlantic, Southwest Atlantic, Eastern Pacific, and Indo-West Pacific. However, the petition provides no boundary lines for these identified population segments. As such, it is difficult to determine the discreteness and significance of these populations without knowing how to separate these populations, such as the Northwest and Southwest Atlantic populations. Therefore, we had to make assumptions regarding the boundary lines. Below we explain where we made assumptions and provide our evaluation of the qualification of these populations as DPSs under our DPS policy.
In terms of discreteness, the petition asserts that the identified populations are ``markedly separate from each other as a result of multiple types of barriers that separate the different populations.'' Specifically, the petition identifies deep ocean areas as areas that contain the ``wrong habitat'' for the species and which act as barriers to movement between the petition's identified populations. The petition cites Bester (undated) and Hayes (2007) as support that the species avoids open-ocean and trans-oceanic movements. Additionally, the petitioner cites Diemer et al. (2011) to support its statement that the smooth hammerhead shark has less vagility, or freedom to move about, compared to
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other shark species, therefore making it unlikely that ``populations will connect or reconnect even if they are only separated by relatively short distances.''
In evaluating the information within Bester (undated), we found no data to suggest that the species cannot make open-ocean or trans-
oceanic movements. In the Hayes (2007) paper, the author notes ``As semi-oceanic species, they hammerhead sharks can be found from continental and insular shelves to deeper water just beyond the shelves, but avoid open-ocean and transoceanic movements (Compagno, 1984).'' This statement refers generally to hammerhead sharks and does not specify species. Additionally, in reviewing the Compagno (1984) reference in Hayes (2007), there is no information to indicate that the species is not capable of these movements. In fact, in describing the habitat and biology of smooth hammerhead sharks, Compagno (1984) states that the species is an ``active, common, coastal-pelagic and semi-
oceanic hammerhead, found . . . at depths from the surface down to at least 20 m and probably much more.'' While the petitioner notes that this species may be less vagile than other species of sharks (that share similar depth ranges), thus suggesting a low potential for mixing of S. zygaena populations, we have no evidence to indicate that any populations of the smooth hammerhead shark are, in fact, markedly separated from other populations of the species.
In our review of the best scientific and commercial information available, we found evidence to indicate that smooth hammerhead sharks are capable of long-distance movements, and, hence, the ability to potentially mix with other populations, with no data to suggest that they could not make trans-oceanic migrations. While the petition only references Diemer et al. (2011) as support for limited maximum and average annual movements, and, thus, low vagility for smooth hammerhead sharks (i.e., 384 km and 141.8 km, respectively), we found three additional studies that provided information on movements of S. zygaena, and whose results indicate that S. zygaena travels significantly farther distances than those reported in the petition. For example, Kohler and Turner (2001) provided available tagging data from recaptured adult smooth hammerhead sharks (n = 6) and found observed maximum distance travelled for S. zygaena to be 919 km, with a maximum speed of 4.8 km/day. In June 2015, NOAA scientists tagged a female smooth hammerhead shark (~213 cm FL) off San Clemente Island, CA. Data from the tag showed that the animal traveled more than 400 miles south to the central Baja Peninsula and then returned north to waters off Ventura, CA, making the total distance traveled equal to more than 1,000 miles (>1,609 km) (SWFSC 2015). Clarke et al. (2015) also noted the ability of the species to travel significant distances, citing a study off New Zealand that found tagged individuals traveled to Tonga, a distance of around 1,200 nm (2,222 km). In fact, Clarke et al. (2015) characterized S. zygaena as the most oceanic of the hammerhead species. This characterization is further supported by Kohler et al. (1998), who showed tagging locations of S. zygaena in the central Atlantic Ocean, between 20deg W. and 30deg W. longitudes, indicating the presence of the species in open-ocean water areas. The presence of smooth hammerhead sharks in oceanic waters is also confirmed by fisheries data from the southwest Atlantic (Amorim et al. 2011), tropical Atlantic Ocean (Matsushita and Matsunaga 2002; Dai et al. 2009), and eastern Pacific Ocean (Romaacuten-Verdesoto 2015). Given the above information on long-distance movements and presence in oceanic waters, we do not find that the populations identified by the petitioner are markedly separate from each other as a consequence of physical or habitat barriers.
The petition also asserts that populations of smooth hammerhead sharks are genetically distinct from each other, but notes that ``there is not extensive species-specific genetic differentiation information available.'' The petition cites Duncan et al. (2006), who examined the global phylogeography of the scalloped hammerhead shark and compared haplotypes of S. lewini to those of nine individuals of S. zygaena. The origin of these 9 S. zygaena samples were only identified as Atlantic (n = 6), Pacific (n = 2) and Indian (n = 1). The authors found high haplotype diversity for smooth hammerhead sharks (similar to the variation in scalloped hammerhead haplotype diversity); however, this analysis was based on very few samples of S. zygaena from non-specific locations and, therefore, provides no information regarding the genetic discreteness of the petitioner's identified populations, particularly between the Northeast Atlantic and Mediterranean Sea, Northwest Atlantic, and Southwest Atlantic populations, and between the Eastern Pacific and Indo-West Pacific populations. Additionally, the Duncan et al. (2006) study examined mitochondrial DNA (mtDNA). Mitochondrial DNA is maternally-inherited, and, as such, differences in mtDNA haplotypes between populations do not necessarily mean that the populations are substantially reproductively isolated from each other because they do not provide any information on males. As demonstrated in previous findings, in species where female and male movement patterns differ (such as philopatric females but wide-ranging males), analysis of mtDNA may indicate discrete populations, but analysis of nuclear (or bi-
parentally inherited) DNA could show homogenous populations as a result of male-mediated gene flow (see e.g.,loggerhead sea turtle, 68 FR 53947, September 15, 2003, and sperm whale, 78 FR 68032, November 13, 2013).
The petitioners also cite to the genetic information provided in Abercrombie et al. (2005) as support of the genetic differentiation between Pacific and Atlantic Ocean smooth hammerhead individuals. However, similar to the discussion above, this analysis was based on very few S. zygaena samples from non-specific locations (n = 7 samples from Atlantic; n = 34 from Pacific) and, therefore, provides no information regarding the genetic discreteness of the petitioner's identified populations, particularly between the Atlantic populations and between the Indo-West and Eastern Pacific populations. Additionally, neither the petitioner, nor the information in the Abercrombie et al. (2005), discuss the relative importance of the differences in the observed amplicons (segments of chromosomal DNA that undergo amplification and contain replicated genetic material) between the Atlantic and Pacific S. zygaena primers (strands of short nucleic acid sequences that serve as starting points for DNA synthesis) in terms of genetic diversity between these populations. Finally, the petition cites fossil records (Lim et al. 2010) as evidence that would support genetic differentiation amongst populations. The Lim et al. (2010) study used samples of S. zygaena from only one location (South Africa) to examine the phylogeny of all hammerhead species. The study provides no information on the genetic differentiation amongst the populations identified by the petitioner.
As discussed previously in this finding, as well as in the smooth hammerhead shark status review (Miller 2016), very few studies have examined the population structure of S. zygaena. In addition to the studies referenced by the petitioner, we evaluated two other available genetic studies (Naylor et al. (2012) and Testerman (2014)) to determine if they provided evidence to
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support the discreteness of the petitioner's identified populations. Similar to the Duncan et al. (2006) study, Naylor et al. (2012) analyzed mtDNA from S. zygaena individuals. This study also suffered from a small sample size (n = 16), but provided specific locations of the analyzed specimens (4 from Gulf of California, 6 from Northwest Atlantic, 3 from Taiwan, and 1 each from Senegal, Vietnam, and Japan). While these samples do not cover all of the identified petitioner's populations (i.e., no samples from the Southwestern Atlantic, Northeastern and Mediterranean, or Eastern Pacific), they provide some limited information for evaluating the discreteness of the Northwestern Atlantic and Indo-Pacific populations. The results from the Naylor et al. (2012) study show a single cluster of smooth hammerhead sharks, with no evidence to suggest matrilineal genetic partitioning of the species. In other words, the available data do not indicate that the identified Northwestern Atlantic population is markedly separate from the Indo-Pacific population due to genetic differentiation.
In contrast, the Testerman (2014) study found statistically significant matrilineal genetic structuring within oceanic basins and significant genetic partitioning between oceanic basins. Specifically, Testerman (2014) analyzed both mitochondrial control region sequences (mtCR; n = 303, 1,090 bp) and 15 nuclear microsatellite loci (n = 332) from smooth hammerhead sharks collected from eight regional areas: Western North Atlantic (n = 21); western South Atlantic (n = 55); western Indian Ocean (n = 63); western South Pacific (n = 44); western North Pacific (n = 11); eastern North Pacific (n = 55); eastern Tropical Pacific (n = 15); and eastern South Pacific (n = 26). Results from the analysis of mtDNA indicated between-basin genetic structuring between the Atlantic and Indo-Pacific basins (mtCR phisST = 0.8159), and shallow genetic variation among individuals from the Atlantic, eastern Tropical/South Pacific, western North Pacific, and western Indian Ocean. Analysis of the nuclear DNA (which is bi-
parentally inherited) also showed significant genetic structure between ocean basins (nuclear FST = 0.0495), with the Atlantic and Indo-Pacific considered to comprise two genetically distinct populations (Testerman 2014). However, unlike the mtDNA results, no significant structure was detected within oceanic basins using the nuclear markers, suggesting evidence of potential female philopatry and male mediated gene flow (Testerman 2014). In other words, the available data support genetic differentiation on a broad scale, between the Atlantic and Indo-Pacific basins, but do not provide genetic evidence of the discreteness of the populations identified by the petitioner. Furthermore, the Testerman (2014) study did not include samples from all of the petitioner's identified populations, including the Northeast Atlantic and Mediterranean population or the eastern Indian Ocean (with the assumption that these individuals are part of the identified Indo-
West Pacific population). Additionally, as Testerman (2014) indicates, more studies are needed, and in particular studies using samples from individual smooth hammerhead sharks of known size class and gender, to further refine the population structure of the smooth hammerhead shark and confirm the above results. Given the best available information, we do not find that the populations identified by the petitioners are markedly separate from each other as a consequence of genetic differences.
Finally, the petition asserts that the populations are ``delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, and regulatory mechanisms exist.'' The petition notes that the range of the smooth hammerhead shark is global, and, as such, extends across international government boundaries and waters regulated by different RFMOs. The petition references its discussion of the ``Inadequacy of Existing Regulatory Mechanisms'' as evidence of the overutilization of the species due to differences in control of exploitation of the species, management of habitat, conservation status, and regulatory mechanisms. The petition argues that because ``various international, national, regional, and RFMO regulations relevant to the species exist throughout all of the aforementioned populations, and since exploitation in these populations varies, they all meet the discreteness requirement.''
We find that the populations identified by the petitioner are not delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, and regulatory mechanisms exist that are significant in light of Section 4(a)(1)(D) of the ESA. Firstly, we note that three of the petitioner's identified populations (the Northeast Atlantic and Mediterranean Sea population, the Northwest Atlantic population, and the Southwest Atlantic population) are governed by the same RFMO, ICCAT. The ICCAT convention area covers all waters of the Atlantic as well as adjacent Seas, including the Mediterranean. In 2010, ICCAT adopted recommendation 10-08 prohibiting the retention onboard, transshipment, landing, storing, selling, or offering for sale any part or whole carcass of hammerhead sharks of the family Sphyrnidae (except for S. tiburo) taken in the Convention area in association with ICCAT fisheries. In other words, these populations are not delimited by international governmental boundaries within which differences in the control of exploitation of the species exist as these populations are all governed under the same RFMO, which presently prohibits the retention and sale of the smooth hammerhead shark in its fisheries. Additionally, the RFMO GFCM, whose convention area covers Mediterranean waters and the Black Sea, passed a similar recommendation based on ICCAT 10-08, further supporting the finding that the regulations governing the exploitation of the Northeast Atlantic and Mediterranean Sea population (e.g., the prohibition of retention and selling of S. zygaena individuals) are no different than those governing the exploitation of the Northwest Atlantic population or Southwest Atlantic population.
Secondly, we did not find evidence of the overutilization of any of the populations identified by the petitioner due to differences in control of the exploitation of the species, management of habitat, conservation status, or regulatory mechanisms across international governmental boundaries. The status review report (Miller 2016) provides a detailed discussion of the threat of overutilization, and presents this analysis by region. These regional discussions encapsulate the petitioner's identified populations, and, therefore, can be used to evaluate whether differences in the control of exploitation exist that are significant in light of Section 4(a)(1)(D) of the ESA. However, since this finding has already discussed, in detail, the threat of overutilization by region (see Overutilization for Commercial, Recreational, Scientific or Educational Purposes section), below we provide the conclusions as they relate to the petitioner's identified populations.
In the Northwest Atlantic, we find that existing regulatory measures have significantly decreased the mortality of hammerhead sharks from both targeted fishing and bycatch mortality on fishing gear for other large coastal shark species, with current levels unlikely to
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lead to overutilization of the species. In the Southwest Atlantic, we find that smooth hammerhead sharks tend to generally be harvested at low levels and that the available species-specific information does not indicate that overutilization is a significant threat presently contributing to the species' risk of extinction in this region. In the Indo-West Pacific, we find that the best available information, including catch time series and CPUE data, does not indicate that present utilization of the species is contributing significantly to its risk of extinction within this region. In the Eastern Pacific, we find that the best available information does not indicate that the species has suffered declines to the point where it is at risk from depensatory processes or that present utilization levels are impacting populations of S. zygaena to such a degree that would significantly increase the species' risk of extinction in this region.
For the Northeastern and Mediterranean population, while we found that the best available information suggests that smooth hammerhead sharks in the Mediterranean Sea have significantly declined, and acknowledge that existing regulatory mechanisms may not be adequate to prevent overutilization of the smooth hammerhead sharks specifically when they occur in the Mediterranean, the same cannot be concluded for those sharks when they occur in the Northeastern Atlantic. Available hammerhead-specific information from the Northeastern Atlantic shows a variable trend in the catch and abundance of hammerhead sharks over the past decade, and without additional information on present abundance levels, distribution information, or catch and overall utilization rates of the smooth hammerhead shark, we found that the best available information does not indicate that overutilization is a threat significantly contributing to the species' risk of extinction in this region. Additionally, as noted previously, the current regulations managing the exploitation of the Northeastern and Mediterranean population are not significantly different across international governmental boundaries.
Given the above findings on the exploitation of the populations identified by the petitioner, as well as the information on the other ESA Section 4(a)(1) factors discussed previously in this finding, we do not find that the petitioner's identified populations are delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, and regulatory mechanisms exist that are significant in light of Section 4(a)(1)(D) of the ESA.
As stated in the joint DPS policy, Congress expressed its expectation that the Services would exercise authority with regard to DPSs sparingly and only when the biological evidence indicates such action is warranted. Based on our evaluation of the best available scientific information, we do not find biological evidence to suggest that any of the populations identified by the petitioner meet the discreteness criterion of the DPS Policy. Because the identified populations are not discrete from each other, we do not need to determine whether the identified populations are significant to the global taxon of smooth hammerhead sharks, per the DPS policy. As such, we find that none of the population segments identified by the petitioner qualify as a DPS under the DPS policy and, therefore, none warrant listing under the ESA.
Similarity of Appearance Listing
The Defenders of Wildlife petition requested that we also consider listing the smooth hammerhead shark as threatened or endangered based on its similarity of appearance to the listed scalloped hammerhead shark DPSs. Section 4 of the ESA (16 U.S.C. 1533(e)) provides that the Secretary may treat any species as an endangered or threatened species even though it is not listed pursuant to Section 4 of the ESA when the following three conditions are satisfied: (1) Such species so closely resembles in appearance, at the point in question, a species which has been listed pursuant to such section that enforcement personnel would have substantial difficulty in attempting to differentiate between the listed and unlisted species; (2) the effect of this substantial difficulty is an additional threat to an endangered or threatened species; and (3) such treatment of an unlisted species will substantially facilitate the enforcement and further the policy of this chapter (16 U.S.C. 1533(e)(A)-(C)).
While we find that the smooth and scalloped hammerhead sharks do closely resemble each other in appearance, we do not find that this resemblance poses an additional threat to the listed scalloped hammerhead shark, nor do we find that treating the smooth hammerhead shark as an endangered or threatened species will substantially facilitate the enforcement of current ESA prohibitions or further the policy of the ESA. As described in the scalloped hammerhead shark final rule (79 FR 38213; July 3, 2014) and critical habitat determination (80 FR 71774; November 17, 2015), the significant operative threats to the listed scalloped hammerhead DPSs are overutilization by foreign industrial, commercial, and artisanal fisheries and inadequate regulatory mechanisms in foreign nations to protect these sharks from the heavy fishing pressure and related mortality in waters outside of U.S. jurisdiction. While three of the listed DPSs have portions of their range within U.S. waters (i.e., the Central and Southwest Atlantic DPS, Eastern Pacific DPS, and Indo-West Pacific DPS), the take and trade of scalloped hammerhead sharks by persons under U.S. jurisdiction were not identified as significant threats to the listed DPSs. In fact, for the threatened scalloped hammerhead shark DPSs (i.e., the Central and Southwest Atlantic DPS and Indo-West Pacific DPS), we determined that prohibiting these activities would not have a significant effect on the extinction risk of those DPSs (79 FR 38213; July 3, 2014). For the Eastern Pacific DPS, while take and trade of this DPS by persons under U.S. jurisdiction were not identified as significant threats, the take prohibitions of section 9(a)(1) of the ESA (16 U.S.C. 1538(a)(1)) automatically apply because it is listed as endangered under the ESA. Overall, interaction with the listed scalloped hammerhead shark DPSs by fishermen under U.S. jurisdiction is negligible.
Additionally, the United States does not have a significant presence in the international fin trade, with U.S. exports and imports of all species of shark fins comprising less than 0.50 percent of the total number of fins globally exported and imported (based on 2009-2013 data from U.S. Census Bureau, available at: http://www.st.nmfs.noaa.gov/commercial-fisheries/foreign-trade/index, and from the FAO, available at: http://www.fao.org/fishery/statistics/global-commodities-production/en). As such, it was determined that any conservation actions for the listed scalloped hammerhead shark DPSs that would bring these DPSs to the point that the measures of the ESA are no longer necessary will need to be implemented by foreign nations.
In terms of the impact of fishing pressure on the listed scalloped hammerhead shark DPSs by U.S. fishermen, as the final rule details, this additional mortality is not viewed as contributing significantly to the identified threats of overutilization and inadequate regulatory measures to the listed DPSs (79 FR 38213; July 3, 2014). This is primarily a result of the negligible interaction between U.S.
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fishermen and the listed scalloped hammerhead shark DPSs, with the listed DPSs rarely caught by persons under U.S. jurisdiction (Miller et al. 2014a). Furthermore, current U.S. fishery regulations prohibiting the landing of scalloped hammerhead sharks also prohibit the landing of smooth hammerhead sharks. For example, in the Atlantic Ocean, including the Caribbean Sea, Atlantic HMS commercially-permitted vessels that have pelagic longline gear on board, and dealers buying from these vessels, have been prohibited from retaining onboard, transshipping, landing, storing, selling, or offering for sale any part or whole carcass of hammerhead sharks of the family Sphyrnidae (except for the S. tiburo) (76 FR 53652; August 29, 2011). As such, there is unlikely to be any enforcement issue requiring officials to distinguish between, for example, endangered Eastern Atlantic DPS of scalloped hammerhead sharks and smooth hammerhead sharks as both species are prohibited from being landed.
In the Pacific, the core range of the endangered Eastern Pacific DPS is outside of U.S. jurisdiction (80 FR 71774; November 17, 2015). Based on the information from the scalloped hammerhead shark status review (Miller et al. 2014a), catch of this DPS by U.S. fishermen is extremely rare. In fact, observer data collected from 1993 to 2015 indicate that no scalloped hammerhead sharks have been observed caught by large U.S. purse seine vessels (>363 mt capacity) operating in the Eastern Pacific Ocean since 2006 (C. Barroso, Fishery Policy Analyst, personal communication 2016). Furthermore, the U.S. States and territories located in the Pacific have passed laws addressing the possession, sale, trade, or distribution of shark fins, which will further discourage landing of scalloped hammerhead sharks. These U.S. states and territories (and year that law was passed) include Hawaii (2010), California (2011), Oregon (2011), Washington (2011), the Commonwealth of the Northern Mariana Islands (2011), Guam (2011), and American Samoa (2012). As such, it is unlikely that U.S. fishermen will be landing hammerhead species in the United States if their fins cannot be traded. Hence, we do not foresee enforcement difficulties related to distinguishing between hammerhead species. As an additional note, the states of Illinois (2012), Maryland (2013), Delaware (2013), New York (2013), and Massachusetts (2014) have also passed similar laws prohibiting the possession, sale, trade, or distribution of shark fins.
With the passage of the U.S. Shark Conservation Act (Pub. L. 111-
348, Jan. 4, 2011), except for smooth dogfish sharks (Mustelus canis), it is also now illegal to ``remove any of the fins of a shark (including the tail) at sea; to have custody, control, or possession of any such fin aboard a fishing vessel unless it is naturally attached to the corresponding carcass; to transfer any such fin from one vessel to another vessel at sea, or to receive any such fin in such transfer, without the fin naturally attached to the corresponding carcass; or to land any such fin that is not naturally attached to the corresponding carcass, or to land any shark carcass without such fins naturally attached.'' As mentioned in the U.S. Shark finning report to Congress (NMFS 2014a), these provisions have improved the ability of U.S. enforcement personnel to enforce shark finning prohibitions in domestic shark fisheries. These shark finning prohibitions also facilitate enforcement of ESA prohibitions as any landed hammerhead shark will have its fins attached to its corresponding carcass. As noted in the NMFS Shark Fin ID Guide, while the first dorsal fins of the smooth and scalloped hammerhead shark are ``almost indistinguishable,'' the pectoral fins differ in coloration and can be ``easily identified'' (Abercrombie et al. 2013). Specifically, in scalloped hammerhead sharks, the ventral surfaces of the pectoral fins have dark patches concentrated at the apex whereas smooth hammerheads lack this dark patch. Since these sharks must be landed with all their fins naturally attached to the carcass, enforcement officials at U.S. ports can use the differences in pectoral fin coloration to differentiate between the species. If the cephalophoil (or head) of the hammerhead shark is also left on the carcass, it provides an additional morphological distinction that can be used to differentiate the species as the smooth hammerhead shark lacks the central indentation that is found on the scalloped hammerhead shark cephalophoil. Regardless, as previously mentioned, there are no ESA take prohibitions for the threatened scalloped hammerhead sharks found in U.S. waters in the Caribbean (Central and Southwest Atlantic DPS) or western Pacific (Indo-West Pacific DPS) and coupled with the other state and Federal fishery regulations that have been implemented in U.S. Atlantic and Pacific waters, it will largely be unnecessary for enforcement personnel to differentiate between landed smooth and scalloped hammerhead sharks for the furtherance of the ESA.
For the reasons above, we do not find it advisable to further regulate the commerce or taking of the smooth hammerhead shark by treating it as an endangered or threatened species based on similarity of appearance to the listed scalloped hammerhead shark DPSs.
Final Determination
Section 4(b)(1) of the ESA requires that NMFS 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 (80 FR 48053; August 11, 2015), the status review report (Miller 2016), and other published and unpublished information, and have consulted with species experts and individuals familiar with smooth hammerhead sharks. We considered each of the statutory factors to determine whether it presented an extinction risk to the species on its own, now or in the foreseeable future, and also considered the combination of those factors to determine whether they collectively contributed to the extinction risk of the species, now or in the foreseeable future. As previously explained, we could not identify any portion of the species' range that met both criteria of the SPR policy. Additionally, we did not find biological evidence that would indicate that the population segments identified by the petitioner qualify as DPSs under the DPS policy. 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 species throughout its entire range.
Based on our consideration of the best available scientific and commercial information, as summarized here and in Miller (2016), we find that the smooth hammerhead shark faces an overall low risk of extinction and conclude that the species is not currently in danger of extinction throughout its range nor is it likely to become so within the foreseeable future. Accordingly, the smooth hammerhead shark does not meet the definition of a threatened or endangered species, and thus, the smooth hammerhead shark does not
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warrant listing as threatened or endangered at this time. This is a final action, and, therefore, we do not solicit comments on it.
References
A complete list of all references cited herein is available upon request (see FOR FURTHER INFORMATION CONTACT).
Authority
The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: June 20, 2016.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine Fisheries Service.
FR Doc. 2016-15200 Filed 6-27-16; 8:45 am
BILLING CODE 3510-22-P
