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Draft 2017 Marine Mammal Stock Assessment Reports

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


Notice; request for comments.


NMFS reviewed the Alaska, Atlantic, and Pacific regional marine mammal stock assessment reports (SARs) in accordance with the Marine Mammal Protection Act. SARs for marine mammals in the Alaska, Atlantic, and Pacific regions were revised according to new information. NMFS solicits public comments on the draft 2017 SARs.


Comments must be received by March 19, 2018.


The 2017 draft SARs are available in electronic form via the internet at​national/​marine-mammal-protection/​draft-marine-mammal-stock-assessment-reports.

Copies of the Alaska Regional SARs may be requested from Marcia Muto, Alaska Fisheries Science Center, NMFS, 7600 Sand Point Way NE, Seattle, WA 98115-6349.

Copies of the Atlantic, Gulf of Mexico, and Caribbean Regional SARs may be requested from Elizabeth Josephson, Northeast Fisheries Science Center, 166 Water St., Woods Hole, MA 02543.

Copies of the Pacific Regional SARs may be requested from Jim Carretta, Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508.

You may submit comments, identified by NOAA-NMFS-2017-0065, by either of the following methods:

Federal e-Rulemaking Portal: Go to​#!docketDetail;​D=​NOAA-NMFS-2017-0065, click the “Comment Now!” icon, complete the required fields, and enter or attach your comments.

Mail: Send comments or requests for copies of reports to: Chief, Marine Mammal and Sea Turtle Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3226, Attn: Stock Assessments.

Instructions: NMFS may not consider comments if they are sent by any other method, to any other address or individual, or received after the end of the comment period. All comments received are a part of the public record and will generally be posted for public viewing on 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).

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Lisa Lierheimer, Office of Protected Resources, 301-427-8402,; Marcia Muto, 206-526-4026,, regarding Alaska regional stock assessments; Elizabeth Josephson, 508-495-2362,, regarding Atlantic, Gulf of Mexico, and Caribbean regional stock assessments; or Jim Carretta, 858-546-7171,, regarding Pacific regional stock assessments.

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Section 117 of the Marine Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.) requires NMFS and the U.S. Fish and Wildlife Service (FWS) to prepare stock assessments for each stock of marine mammals occurring in waters under the jurisdiction of the United States, including the Exclusive Economic Zone. These reports must contain information regarding the distribution and abundance of the stock, population growth rates and trends, estimates of annual human-caused mortality and serious injury (M/SI) from all sources, descriptions of the fisheries with which the stock interacts, and the status of the stock. Initial reports were completed in 1995.

The MMPA requires NMFS and FWS to review the SARs at least annually for strategic stocks and stocks for which significant new information is available, and at least once every three years for non-strategic stocks. The term “strategic stock” means a marine mammal stock: (A) For which the level of direct human-caused mortality exceeds the potential biological removal level or PBR (defined Start Printed Page 60182by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population); (B) which, based on the best available scientific information, is declining and is likely to be listed as a threatened species under the Endangered Species Act (ESA) within the foreseeable future; or (C) which is listed as a threatened species or endangered species under the ESA. NMFS and the FWS are required to revise a SAR if the status of the stock has changed or can be more accurately determined.

Prior to public review, the updated SARs under NMFS' jurisdiction are peer-reviewed within NMFS' Fisheries Science Centers and by members of three regional independent Scientific Review Groups (SRGs), which were established under the MMPA to independently advise NMFS on information and uncertainties related to the status of marine mammals.

The period covered by the 2017 draft SARs is 2011-2015. NMFS reviewed the status of marine mammal stocks as required and revised a total of 67 reports representing 75 stocks in the Alaska, Atlantic, and Pacific regions to incorporate new information. The 2017 revisions consist primarily of updated or revised M/SI estimates and updated abundance estimates. One stock (Gulf of Maine humpback whale) changed in status from non-strategic to strategic, and three stocks (California/Oregon/Washington (CA/OR/WA) Mesoplodont beaked whales, CA/OR/WA Cuvier's beaked whale, and Hawaii pelagic false killer whale) changed in status from strategic to non-strategic. Substantive revisions to the SARs are discussed below. NMFS solicits public comments on the draft 2017 SARs.

Guidelines for Assessing Marine Mammal Stocks (GAMMS)

The MMPA provides only general guidance on assessment methods and on the content of the reports. As a result, NMFS and FWS have held a series of workshops (1994, 1996, 2003, and 2011) to develop guidelines for consistently assessing marine mammal stocks and developing reports. The guidelines were most recently revised in 2016 (NMFS 2016), based on the 2011 GAMMS workshop, after opportunity for the public to review and provide comments (81 FR 10830, March 2, 2016). The 2017 draft reports reflect the first year that the 2016 revised guidelines have been applied.

Humpback Whales

On September 8, 2016, NMFS published a final rule revising the listing status of humpback whales under the ESA (81 FR 62259). We divided the globally listed endangered species into 14 distinct population segments (DPSs), removed the species-level listing, and in its place, listed four DPSs as endangered and one DPS as threatened. Based on their current statuses, the remaining nine DPSs did not warrant listing. Upon the effective date of the final rule, October 11, 2016, humpback whales listed as threatened or endangered retained their depleted status under the MMPA, and humpback whales not listed as threatened or endangered lost their depleted status under the MMPA.

In response to this revision to the humpback whale listing status, NMFS is currently evaluating the humpback whale stock delineations under the MMPA to determine whether we can align the stocks with the DPSs under the ESA. We note that the DPSs established in this final rule that occur in waters under the jurisdiction of the United States do not necessarily equate to the existing MMPA stocks for which Stock Assessment Reports (SARs) have been published in accordance with section 117 of the MMPA (16 U.S.C. 1386). As described in our Federal Register notice requesting comments on the Draft 2016 Marine Mammal Stock Assessment Reports (81 FR 70097, October 11, 2016), until we have completed our review of the MMPA stock delineations, we will treat existing MMPA stocks that fully or partially coincide with a listed DPS as depleted, and stocks that do not fully or partially coincide with a listed DPS as not depleted for management purposes. Therefore, in the interim, we will treat the Western North Pacific, Central North Pacific, and California/Oregon/Washington stocks as endangered and depleted because they partially or fully coincide with ESA-listed DPSs, and we will treat the Gulf of Maine and American Samoa stocks as no longer depleted because they do not coincide with any ESA-listed DPS. Any changes in stock delineation or MMPA section 117 elements (such as PBR or strategic status) will be reflected in future stock assessment reports, and the Scientific Review Groups and the public will be provided opportunity to review and comment.

Alaska Reports

In 2017, NMFS reviewed all 45 stocks in the Alaska region, and updated SARs under NMFS jurisdiction for 18 stocks (13 strategic and 5 non-strategic). Reports for the following strategic stocks were revised for 2017: Steller sea lion, Western U.S.; northern fur seal, Eastern Pacific; beluga whale, Cook Inlet; killer whale, AT1 Transient; harbor porpoise, Southeast Alaska, Gulf of Alaska, and Bering Sea stocks; sperm whale, North Pacific; humpback whale, Western North Pacific and Central North Pacific stocks; fin whale, Northeast Pacific; North Pacific right whale, Eastern North Pacific; and bowhead whale, Western Arctic. Reports for the following non-strategic stocks were revised for 2017: Spotted seal, Alaska; and beluga whale, Beaufort Sea, Eastern Chukchi Sea, Eastern Bering Sea, and Bristol Bay stocks. Information on the remaining Alaska region stocks can be found in the final 2016 reports (Muto et al., 2017).

Most revisions to the Alaska SARs included updates of abundance and/or M/SI estimates, including revised abundance estimates for the Western U.S. stock of Steller sea lions; Eastern Pacific northern fur seals; Alaska spotted seals; Eastern Chukchi Sea, Eastern Bering Sea, and Bristol Bay stocks of beluga whales; and Western Arctic bowhead whales.

Atlantic Reports

In 2017, NMFS reviewed all 116 stocks in the Atlantic region (including the Atlantic Ocean, Gulf of Mexico, and U.S. territories in the Caribbean), and updated SARs for 21 stocks under NMFS jurisdiction (13 strategic and 8 non-strategic). The reports for the following strategic stocks were revised for 2017: North Atlantic right whale, western Atlantic; humpback whale, Gulf of Maine; fin whale, Western North Atlantic (WNA); Bryde's whale, Gulf of Mexico; and 9 common bottlenose dolphin stocks (WNA northern migratory coastal; WNA southern migratory coastal; WNA South Carolina/Georgia coastal; WNA northern Florida coastal; WNA central Florida coastal; northern North Carolina Estuarine System; southern North Carolina Estuarine System; Barataria Bay Estuarine System; and Mississippi Sound, Lake Borgne, Bay Boudreau).

Reports for the following non-strategic stocks were revised for 2017: Minke whale, Canadian east coast; Risso's dolphin, WNA; Atlantic white-sided dolphin, WNA; common dolphin, WNA offshore; harbor porpoise, Gulf of Maine/Bay of Fundy; harbor seal, WNA; gray seal, WNA; and harp seal, WNA. Information on the remaining Atlantic region stocks can be found in the final 2016 reports (Waring et al., 2017).

Most revisions to the Atlantic SARs included updates of abundance and/or M/SI estimates. New abundance estimates are available for the North Start Printed Page 60183Atlantic right whale, western Atlantic; humpback whale, Gulf of Maine; and seven common bottlenose dolphin stocks (5 WNA coastal stocks, and 2 Gulf of Mexico stocks). For the 2017 SAR cycle, NMFS rewrote seven Atlantic common bottlenose dolphin reports (5 WNA coastal stocks, and the Northern North Carolina and Southern North Carolina Estuarine System Stocks) to address general comments from the SRG. Therefore, the reader will not see tracked changes in the draft 2017 reports for these stocks.

The draft 2017 North Atlantic right whale, western Atlantic SAR provides an updated abundance estimate for right whales of 455, based on a new statistical model for estimating abundance (Pace et al., in press). When comparing the minimum abundance estimate from the 2016 SAR, the abundance appears to increase from 440 (final 2016 SAR) to 455 (draft 2017 SAR). However, these estimates are not comparable as they were derived using different methodologies. Prior assessments used counts of different individuals seen in a year, combined with some assumptions about deaths among those animals seen in prior years but not in the current year—the minimum number alive. In recent years, this method has been confounded by a change in right whale behavior: Whales are not being sighted at the times and places where they have historically been found and therefore are less likely to be sighted. The new statistical model for estimating abundance results in an estimate that is more current and more representative of the population trend than the minimum number alive method of the past. The model results of the time-series of abundance estimates show that abundance has slowly declined since 2010, after relatively steady increases since the early 1990s. However, M/SI estimates continue to be calculated based on the number reported. The mortality of female right whales is substantially (~50%) higher than males, and there are presently 1.5 males for each female in the species.

As a result of the humpback whale ESA listing rule (81 FR 62259; September 8, 2016), the Gulf of Maine stock of humpback whales is no longer considered ESA listed or depleted. Based on the most recent line-transect survey, the estimate of abundance for the Gulf of Maine humpback whales is 335, with a minimum population estimate of 239 whales. The previous estimate of 823 was based on data that are now considered outdated (greater than 8 years old) and those data were not included in this most recent abundance estimate; thus, the 2017 abundance estimate is considered negatively biased and likely not a true reflection of the size of the stock. Although the abundance appears to decline from 2016 to 2017, these estimates should not be compared as they were derived using different methodologies and data sets. As a result of the lower abundance estimate, the PBR for the Gulf of Maine humpback whale stock was reduced from 13 to 3.7 whales. The estimate of human-caused M/SI is now above PBR; thus, the stock has changed from non-strategic to strategic. However, because the abundance estimate is fairly imprecise, incomplete in coverage, and known to be negatively biased, the uncertainties associated with this assessment may have produced an incorrect determination of strategic status.

Abundance estimates were updated for the Barataria Bay Estuarine System (BBES) and the Mississippi Sound, Lake Borgne, Bay Boudreau (MS) stocks of common bottlenose dolphins in the draft 2017 SARs. The abundance estimates were derived using a spatially-explicit capture-mark-recapture model using photo-identification data collected during 2010-2014 (McDonald et al., 2017, Hornsby et al., 2017). The best estimate of abundance for the BBES stock of common bottlenose dolphins is 2,306, and the minimum population estimate is 2,138 bottlenose dolphins; both of these estimates were previously listed as “unknown” is the last revised SAR (2015). The updated PBR for the BBES stock of common bottlenose dolphins is 21. The updated best abundance estimate for the MS stock is 3,046, and the minimum abundance estimate is 2,896 (901 and 551, respectively, in the 2015 SAR). The abundance estimate for the MS stock is substantially higher than estimates reported in the 2015 SAR which were derived from aerial surveys. The updated estimate is still an underestimate of total stock size. The resulting PBR for the MS stock is 29 (5.6 in the 2015 SAR). The current best abundance estimate for common dolphins off the U.S. Atlantic coast is 70,184. This estimate, derived from 2011 shipboard and aerial surveys, is the only current estimate available. This estimate is substantially lower than the estimate from the 2015 SAR (173,486), because the previous estimate included data from the 2007 Trans-North Atlantic Sighting survey of Canadian waters. As recommended in the GAMMS (NMFS 2016), estimates older than eight years are unreliable, so this new estimate does not include data from the 2007 Canadian survey. The estimate should not be interpreted as a decline in abundance of this stock, as previous estimates are not directly comparable.

The best estimate of abundance for the western North Atlantic stock of gray seals in Canada is 424,300 (CV = 0.16) using model-based abundance estimates derived from pup surveys. The ratio of total population size to pups in Canada is applied to the count of pups born in U.S. waters in 2016 (6,274), to approximate an Nbest and Nmin for gray seals in the U.S. The best estimate of abundance of gray seals in U.S waters is 26,985 (95% CI: 22,042-33,036) and the minimum abundance in U.S. waters is 25,768. There is uncertainty in these abundance levels in the U.S. because life history parameters that influence the ratio of pups to total individuals in this portion of the population are unknown. Based on the minimum population estimate in U.S. waters, PBR for the portion of the stock in U.S. waters is 1,546. In U.S. waters, human-caused mortality does not exceed PBR.

Pacific Reports

In 2017, NMFS reviewed and considered for revising all 85 stocks in the Pacific region (waters along the west coast of the United States, within waters surrounding the main and Northwestern Hawaiian Islands (NWHI), and within waters surrounding U.S. territories in the Western Pacific), and updated SARs for 36 stocks (10 strategic and 26 non-strategic). The reports for the following strategic stocks were revised for 2017: Hawaiian monk seal; killer whale, Eastern North Pacific Southern Resident; sperm whale, CA/OR/WA; humpback whale, CA/OR/WA; blue whale, Eastern North Pacific; false killer whale, Main Hawaiian Islands (MHI) Insular; sperm whale, Hawaii (HI); blue whale, Central North Pacific; fin whale, HI; and sei whale, HI.

Reports for the following non-strategic stocks were revised for 2017: Baird's beaked whale, CA/OR/WA; Cuvier's beaked whale, CA/OR/WA; Mesoplodont beaked whales, CA/OR/WA; rough-toothed dolphin, HI; Risso's dolphin, HI; common bottlenose dolphin, Hawaiian Islands Stock Complex (five stocks: HI pelagic, Kaua'i and Ni'ihau, O'ahu, 4-Islands region, and Hawaiian Island); pantropical spotted dolphin, Hawaiian Islands Stock Complex (four stocks: HI pelagic, O'ahu, 4-Islands region, and HI Island); striped dolphin, HI pelagic; Fraser's dolphin, HI; melon-headed whale, Hawaiian Islands; pygmy killer whale, HI; false killer whale, NWHI; false killer whale, HI pelagic; killer whale, HI; short-finned pilot whale, HI; Blainville's beaked whale, HI Pelagic; Longman's beaked Start Printed Page 60184whale, HI; Cuvier's beaked whale, HI pelagic; and Bryde's whale, HI. The HI pelagic false killer whale, CA/OR/WA Mesoplodont beaked whales, and CA/OR/WA Cuvier's beaked whale stocks changed from strategic to non-strategic because their five-year mortality and serious injury estimates for 2011-2015 are less than their PBRs. Information on the remaining Pacific region stocks can be found in the final 2016 reports (Carretta et al., 2017).

Several abundance estimates for Pacific stocks were updated in the draft 2017 reports based on a new analysis of a 2010 pelagic line-transect survey within the U.S. Exclusive Economic Zone (EEZ) around the Hawaiian Islands (Bradford et al., 2017a), a mark-recapture photo-ID analysis of MHI Insular false killer whales (Bradford et al., 2017b), and completed 2015 field studies of Hawaiian monk seals (Johanos 2017). The updated estimates of abundance for California Current beaked whales are based on a recent trend-based analysis (Moore and Barlow 2017).

The Hawaii pelagic false killer whale stock changed from “strategic” to “non-strategic” because M/SI is now below PBR. However, the stock status is based on information only from within the U.S. EEZ around Hawaii because that is where the stock's abundance has been assessed, even though the stock's range (and fishery bycatch) extends into the adjacent high seas. Mortality and serious injury of this stock outside the EEZ (where there is no PBR) is not factored into the evaluation of stock status.

New approaches were developed to estimate Hawaiian monk seal abundance, both range-wide and at individual subpopulations. In the draft 2017 SAR, the best estimate of the total population size is 1,324 seals with a minimum abundance estimate of 1,261 (1,272 and 1,205, respectively, in the 2016 SAR). Past reports have concluded that Hawaiian monk seal stock dynamics did not conform to the underlying model for calculating PBR because the stock was declining despite being well below OSP. As a result, PBR for the Hawaiian monk seal was undetermined. The trend since 2013 does not indicate the stock has continued to decline, so that PBR may be determined. For the first time, the monk seal SAR provides a valid calculation for PBR of 4.4.

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Dated: December 14, 2017.

Donna S. Wieting,

Director, Office of Protected Resources, National Marine Fisheries Service.

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[FR Doc. 2017-27281 Filed 12-18-17; 8:45 am]