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Table 1
Stock Assessments for 1998
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NOAA Technical Memorandum NMFS-NE-116

U.S. Atlantic Marine Mammal Stock Assessments -- 1998

Gordon T. Waring1, Debra L. Palka1, Phillip J. Clapham1, Steven Swartz2, Marjorie C. Rossman1, Timothy V.N. Cole1, Kathryn D. Bisack1, and Larry J. Hansen3
1National Marine Fisheries Service, 166 Water St., Woods Hole, MA 02543-1026
2National Marine Fisheries Service, 75 Virginia Beach Dr.,Miami, FL 33149-1003
3National Marine Fisheries Service, 219 Ft. Johnson Rd., Charleston, SC 29412

Web version posted September 30, 2002

Citation: Waring GT, Palka DL, Clapham PJ, Swartz S, Rossman MC, Cole TVN, Bisack KD, Hansen LJ. 1999. U.S. Atlantic Marine Mammal Stock Assessments -- 1998. US Dep Commer, NOAA Tech Memo NMFS NE 116; 184 p.

Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office.

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The authors wish to thank and acknowledge Janeen Quintal for her technical assistance throughout the preparation of this report. The authors also wish to acknowledge contributions by the Northeast Fisheries Science Center (NEFSC) Sea Sampling Investigation, Dana Hartley and Kim Thounhurst (Northeast Regional Office), and Blair Mase, Keith Mullin, and Jim Tobias (Southeast Fisheries Science Center). Also, we acknowledge advice and comments provided by NEFSC: Richard Merrick and Fred Serchuk; and the Atlantic Scientific Review Group: Donald Baltz, Solange Brault, Joseph DeAlteris, James Gilbert, Mike Harris, Robert Kenney, Robert MacKinnon, James Mead, Daniel Odell, Andrew Read, Randall Wells, and Graham Worthy. We also thank Paul Wade, NMFS, Office of Protected Species, for his comments and guidance at the SRG review meeting, the Marine Mammal Commission, the Humane Society of the United States, the Blue Water Fishermen’s Association and Hal Caswell (Woods Hole Oceanographic Institution) for their constructive comments and advice.


Under the 1994 amendments of the Marine Mammal Protection Act (MMPA), the National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (USFWS) were required to generate stock assessment reports (SAR) for all marine mammal stocks in waters within the U.S. Exclusive Economic Zone (EEZ). The first reports for the Atlantic (includes the Gulf of Mexico) were published in July 1995 (Blaylock et al. 1995). The MMPA requires NMFS and USFWS to review these reports annually for strategic stocks of marine mammals and at least every 3 years for stocks determined to be non-strategic. The second edition of the SARs (1996 assessments) was published in October 1997 and contained all the previous reports, but major revisions and updating were only completed for strategic stocks (Waring et al. 1997). Updated reports were identified by a 1997 date-stamp at the top right corner at the beginning of each report. The current report contains only assessment reports for the Atlantic stocks, and updated reports are identified by a December 1998 date-stamp. This format was selected to facilitate availability and because the draft 1999 SARs are expected to be available in February 1999.

This report was prepared by staff of the Northeast Fisheries Science Center (NEFSC), and Southeast Fisheries Science Center (SEFSC). NMFS staff presented the reports at the May 1998 meeting of the Atlantic Scientific Review Group (ASRG), and subsequent revisions were based on their contributions and constructive criticism. In July 1998, the revised report was available for a 90-day public comment period. The current version reflects changes made in response to the public comments.

Table 1 contains a summary, by species, of the information included in the stock assessments, and also indicates those that have been revised since the 1997 publication. A total of 27 of the 31 Atlantic stock assessment reports were revised for 1998. Most proposed changes incorporate new information into abundance or mortality estimates. The revised SARs include 15 of the strategic stocks and 12 of the non-strategic stocks relative to the 1996 assessments. Some of the revisions clarified fisheries mortality information which resulted in changes to the status of some stocks. Information on human interactions (fishery and ship strikes) between the North Atlantic right whale and North Atlantic humpback whale stocks were re-reviewed and updated. The 1993 fishery induced mortality of a North Atlantic right whale has been reassigned from the pelagic driftnet fishery to the lobster fishery based on a reexamination of all information. Abundance estimates for humpback whales, Canadian east coast stock of Minke whales, Western North Atlantic stocks of common dolphins, and harbor seals have been revised. The Western North Atlantic stock of Atlantic white-sided dolphins is now considered “strategic” based on incidental mortality in the New England sink gillnet and North Atlantic bottom trawl fisheries. The Western North Atlantic stock of long-finned pilot whales will remain “strategic” based on mortality in the Atlantic squid, mackerel, butterfish trawl fishery. The Western North Atlantic stock of pygmy sperm whale is no longer considered “strategic”. One strategic stock that was not updated, but extensively reviewed by the ASRG was the Western North Atlantic stock (stock complex) of coastal
bottlenose dolphins. New information on observed mortality in the 1995-1996 mid-Atlantic coastal gillnet fishery was presented. One mortality was observed in 1996, and the preliminary mortality estimate was 4.1 (CV = 0.88). Fishery effort data are under review and 1996-1997 mortality estimates will be provided in the draft 1999 assessment report.

This is a working document and individual stock assessment reports will be updated as new information becomes available and as changes to marine mammal stocks and fisheries occur. The authors solicit any new information or comments which would improve future stock assessment reports.


Section 117 of the 1994 amendments to the Marine Mammal Protection Act (MMPA) requires that an annual stock assessment report (SAR) for each stock of marine mammals that occurs in waters under U.S. jurisdiction, be prepared by the National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (FWS), in consultation with regional Scientific Review Groups (SRG). The SRGs are a broad representation of marine mammal and fishery scientists and members of the commercial fishing industry mandated to review the marine mammal stock assessments and provide advice to the Assistant Administrator for NMFS. The reports are then made available on the Federal Register for public review and comment before final publication.

The MMPA requires that each SAR contain several items, including: (1) a description of the stock, including its geographic range; (2) a minimum population estimate, a maximum net productivity rate, and a description of current population trend, including a description of the information upon which these are based; (3) an estimate of the annual human-caused mortality and serious injury of the stock, and, for a strategic stock, other factors that may be causing a decline or impeding recovery of the stock, including effects on marine mammal habitat and prey; (4) a description of the commercial fisheries that interact with the stock, including the estimated number of vessels actively participating in the fishery and the level of incidental mortality and serious injury of the stock by each fishery on an annual basis; (5) a statement categorizing the stock as strategic or not, and why; and (6) an estimate of the potential biological removal (PBR) level for the stock, describing the information used to calculate it. The MMPA also requires that SARs be updated annually for stocks which are specified as strategic stocks, or for which significant new information is available, and once every three years for nonstrategic stocks.

Following enactment of the 1994 amendments, the NMFS and FWS held a series of workshops to develop guidelines for preparing the SARs. The first set of stock assessments for the Atlantic Coast (including the Gulf of Mexico) were published in July 1995 in the NOAA Technical Memorandum series (Blaylock et al. 1995). In April 1996, the NMFS held a workshop to review proposed additions and revisions to the guidelines for preparing SARs (Wade and Angliss 1997). Guidelines developed at the workshop were followed in preparing the 1996 (Waring et al. 1997) and 1998 SARs. A 1997 SAR was not produced.

In this document, major revisions and updating of the SARs were only completed for Atlantic Coast strategic stocks and stocks for which significant new information were available. These are identified by the 1998 date-stamp at the top right corner at the beginning of each report. Gulf of Mexico SARs were not updated from Waring (et al. 1997), therefore were not included in this document. Except for some minor editorial changes, stocks designated by the 1995 or 1997 date-stamp are unchanged from the 1997 document (Waring et al. 1997).

In this document, the status of long-finned pilot whale was changed to non-strategic because the 5-year (1992-1996) mean annual mortality in fishing operations was below PBR.


Blaylock, R. A., J. W. Hain, L. J. Hansen, D. L. Palka, and G. T. Waring. 1995. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments. NOAA Tech. Memo. NMFS-SEFSC-363, 211 pp.

Wade, P. R. and R. P. Angliss. 1997. Guidelines for assessing marine mammal stocks: Report of the GAMMS workshop April 3-5, 1996, Seattle, Washington. NOAA Tech. Memo. NMFS-OPR-12, 93 pp.

Waring, G. T., D. L. Palka, K. D. Mullin, J. H. W. Hain, L. J. Hansen, and K. D. Bisack. 1997. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments. NOAA Tech. Memo. NMFS-NE-114, 250 pp.

NOTE: All documents below are PDF files
Table 1. A summary of Atlantic marine mammal stock assessment reports for stocks of marine mammals under NMFS authority that occupay waters under U.S. jurisdiction
NORTH ATLANTIC RIGHT WHALE (Eubalaena glacialis): Western North Atlantic Stock
HUMPBACK WHALE (Megaptera novaeangliae): North Atlantic Stock
FIN WHALE (Balaenoptera physalus): Western North Atlantic Stock
SEI WHALE (Balaenoptera borealis): Western North Atlantic Stock
MINKE WHALE (Balaenoptera acutorostrata): Canadian East Coast Stock
BLUE WHALE (Balaenoptera musculus): Western North Atlantic Stock
SPERM WHALE (Physeter macrocephalus): Western North Atlantic Stock
DWARF SPERM WHALE (Kogia simus): Western North Atlantic Stock
PYGMY SPERM WHALE (Kogia breviceps): Western North Atlantic Stock
KILLER WHALE (Orcinus orca): Western North Atlantic Stock (1995)
PYGMY KILLER WHALE (Feresa attenuata): Western North Atlantic Stock (1995)
NORTHERN BOTTLENOSE WHALE (Hyperoodon ampullatus): Western North Atlantic Stock
CUVIER'S BEAKED WHALE (Ziphius cavirostris): Western North Atlantic Stock
MESOPLODON BEAKED WHALES (Mesoplodon spp.): Western North Atlantic Stock
RISSO'S DOLPHIN (Grampus griseus): Western North Atlantic Stock
LONG-FINNED PILOT WHALE (Globicephala melas): Western North Atlantic Stock
SHORT-FINNED PILOT WHALE (Globicephala macrorhynchus): Western North Atlantic Stock
WHITE-BEAKED DOLPHIN (Lagenorhynchus albirostris): Western North Atlantic Stock (1997)
WHITE-SIDED DOLPHIN (Lagenorhynchus acutus): Western North Atlantic Stock
COMMON DOLPHIN (Delphinus delphis): Western North Atlantic Stock
ATLANTIC SPOTTED DOLPHIN (Stenella frontalis): Western North Atlantic Stock
PANTROPICAL SPOTTED DOLPHIN (Stenella attenuata): Western North Atlantic Stock
STRIPED DOLPHIN (Stenella coeruleoalba): Western North Atlantic Stock
SPINNER DOLPHIN (Stenella longirostris): Western North Atlantic Stock
BOTTLENOSE DOLPHIN (Tursiops truncatus): Western North Atlantic Offshore Stock
BOTTLENOSE DOLPHIN (Tursiops truncatus): Western North Atlantic Coastal Stock (1997)
HARBOR PORPOISE (Phocoena phocoena): Gulf of Maine/Bay of Fundy Stock
HARBOR SEAL (Phoca vitulina): Western North Atlantic Stock
GRAY SEAL (Halichoerus grypus): Western North Atlantic Stock
HARP SEAL (Phoca groenlandica): Western North Atlantic Stock
HOODED SEAL (Cystophora cristata): Western North Atlantic Stock
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