National Marine Fisheries Service U.S DEPARTMENT OF COMMERCE AFSC PROCESSED REPORT 99.08 Marine Mammal Protection Act and Endangered Species Act lmplementation Program 1 gg8 December 1999 This report does not constitute a puHication and is for infrcrmation only All data herein are to be considered provisiona,l. ERRATA NOTICE This document is being made available in .PDF format for the convenience of users; however, the accuracy and correctness of the document can only be certified as was presented in the original hard copy format. Inaccuracies in the OCR scanning process may influence text searches of the .PDF file. Light or faded ink in the original document may also affect the quality of the scanned document. Marine Mammal Protection Act and Endangered Species Act Implementation program 1998 Edited by: Anita L. Lopez Douglas P. DeMaster Annual Reports ofresearch carried out on the population biologt of marine mammals by the National Marine Mammal Laboratory to meet the 1994 amendmenîs to the Marine Mammal Protection Act and the Endangered Species Act Submitted to: Office of Protected Resources National Marine Fisheries Service 1335 East-West Highway Silver Spring, MD 20910 National Oceanic and Atmospheric Administration National Marine Fisheries Service Alaska Fisheries Science Center National Marine Mammal Laboratory 7600 Sand Point Way Northeast Seattle, WA 9S115-0070 December 1999 Preface Beginning in 1991, the National Marine Mammal Laboratory GllÀ/ßifl.) has been partially funded by the National Marine Fisheries Service's (NÀ/mS) Office of Protected Resources to determine the abundance of selected species in U.S. waters of the eastern North Pacific Ocean. On 30 Ãpril1994, Public Law IO3-238 was enacted allowing significant changes to provisions within the Marine Mammal Protection Act (MMPA). Interactions between¡¡ãrin. mammals and commercial fisheries are addressed under three new Sections. This new regime replaced the interim exemption that had regulated fisheries-related incidental takes since 1988. The 1994 MMPA amendments continue NMFS' responsibility to carry out population studies to determine the abundance, distribution and stock identification of marine mammal species that might be impacted by human-related or natural causes. The following report, containing 20 papers, is a compilation of studies carried out with fiscal year l99S (FY98) funding as part of the NMFS MMPAÆSA Implementation program. The report contains information regarding studies conducted on beluga whales, California sea lions, gray whales, harbor porpoise, harbor seals, humpback whales, ice seals, northern fur seals, and Steller sea lions. This report does not constitute a publication and is for information only. All data herein are to be considered provisional. Further, most of the papers included in this ieport may be published elsewhere. Any question concerning the material contained in this document should be directed to the authors, or ourselves. Reference to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA. Anita L.Lopez Douglas P. DeMaster llt MMPAÆSA Implementation Program Report for 1998 Reporting Center: National Marine Mammal Laboratory Alaska Fisheries Science Center Administrative Office: Office of Protected Resources National Marine Fisheries Service Page No. Beluga'Whales: Rugh, D.J., R.C. Hobbs, K.E.V/. Shelden, B.A. Mahoney and L.K. Litzky Aerial surveys of beluga whales in Cook Inlet, Alaska, June 1998. 1 Califomia Sea Lions: Melin, S., R.L. Delong, and J.L. Laake Survival and natality rates of Califomia sea lions (Zalophus californianøs) from a branding study at San Miguel Island, California. 13 Cetaceans (small): Waite, J.M., and R.C. Hobbs Small cetacean aerial survey in Prince William Sound and the western Gulf of Alaska in 1998 and preliminary harbor porpoise Abundance estimates for the Southeast Alaska and the Gulf of Alaska stocks. 39 Hanson, M.8., and W. Xu A preliminary evaluation of the relationship between small cetacean tag design and attachment durations: a bioengineering approach. 55 Gray Whales: Rugh, D.J., R.C. Hobbs, R.P. Angliss, L.S. Baraff, C.D'Vincent, S. Hill, M.M. Muto, M.A. Scillia, K.E.W. Shelden, and J.M.Waite Field report of the 1997198 study of gray whales during their southbound migration. 69 Harbor Porpoise: Hanson, M.8., R.W. Baird, and R.L. Delong Movements of a tagged ha¡bor porpoise in inland'Washington waters from June 1998 to January 1999. 85 Laake, J.L., P.J. Gearin and R.L. Delong Further evaluation of harbor porpoise habituation to pingers in a set gillnet fishery. 97 Hughes, K.M., L.L. Lehman, P.J. Gearin, J.L.Laake, R.L. Delong, and M.E. Gosho Acoustic alarms and Pacific herring (Clupea pallasi). 109 Harbor Seals: Withrow, D.E., J.C. Cesarone, and J.L. Bengtson Abundance and distribution of harbor seals (Phoca vitulina richardsi) for southern Southeast Alaska from Frederick Sorurd to the US/Canada border in 1998. 119 Orr,4., A. Banks, S. Mellman, and H. Huber Food habits of harbor seals (Phoca vitulina) at the Umpqua River dwing 1997 and 1998. 151 Jeffries, S., J. Laake, H. Huber, and R. Delong Report on'Washington harbor seal OSP workshops. t67 Withrow, D.E., and J.C. Cesarone An estimate of the proportion of harbor seals missed during aerial surveys over glacial ice in Alaska. 191 Humpback Whales: Mizroch, S.4., and S.A.D. Harkness Update on the north Pacific humpback whale fluke photograph collection, August 1999. 225 Ice Associated Seals: Bengtson, J.L., and H. Huntington Incorporating traditional knowledge into testable hypothes es of Arctic ice seal ecology 233 vl Northern Fur Seals: Loughlin, T.R., and E.H. Sinclair Northem fur seal studies conducted on the Pribilof Islands,1997. 239 Pinnipeds: Huber, H., L. Park, E. LaHood, G. Mackey and M. purcell Genetic identification of salmonid bone from pinniped food habits samples. 243 Gearin, P.J., K.M. Hughes, L.L. Lehman, R.L. Delong, S.J. Jeffries, and M.E. Gosho Washington state pinniped diet studies 1983-1998. 249 Steller Sea Lions: Chumbley, K. V/inter Steller sea lion prey and foraging studies, (Cruise SMMOCI-99I) 4-25 March 1998. 259 Loughlin, T.R., and S. D. Rice Fatty acid profiles of Steller sea lions and north Pacific Ocean forage fishes. 271 Other: Gearin, P.J., K.M. Hughes, L.L. Lehmffi, L.Cooke, R.L. Delong, and M.E. Gosho Investigations of marine mammal interactions with Lake Ozette sockeye salmon, Oncorhynchus nerkn,1998. 275 vll AERIAL SURVEYS OF BELUGA WHALES IN COOK INLET, ALASKA, JUNE 1998 David J. Rughl, Roderick C. Hobbsr, Kim E.W. Sheldenr, Barbara A. Mahonel' *d Laura K. Litzþl lNational Marine Mammal Laboratory Alaska Fisheries Science Center National Marine Fisheries Service, NOAA 7600 Sand Point Way NE Seattle, V/ashington 98 1 15, U.S.A. and 'Alaska Regional Office National Marine Fisheries Service, NOAA 222W 7th Ave., Box 43 Anchorage, Alaska 99513, U.S.A. Abstract The National Marine Mammal Laboratory G\MML), in cooperation with the NMFS Alaska Regional Office, the Alaska Beluga Whale Committee (ABWC) and the Cook Inlet Marine Mammal Council (CIMMC), conducted an aerial survey of the beluga whale population in Cook Inlet, Alaska, during 9-15 June 1998. The 39.4hr survey was flown in a twin-engine, high-wing aircraft at an altitude o1244 m (800 ft) altitude and speed of 185 km/hr (100 kÐ along a trackline 1.4 km from shore. This provided complete coverage of coastal areas around the entire inlet (1,388 km) one or more times and 1,320 krn of transects across the inlet. Throughout most of this survey, a test of sighting rates was conducted with multiple independent observers on the coastal (left) side of the plane, where virtually all sightings occur. A single observer and a computer operator/data recorder were on the right side. After finding beluga groups, a series of aerial passes were made to allow at least two pairs of observers to make 4 or more counts of each group. The sum of the aerial estimates (using median counts from each site, not corrected for missed whales) ranged from 173 to 192 whales, depending on survey day. There were 57-109 belugas counted near the Susitna River, 42-93 in Knik Arm and 23-42 in Chickaloon Bay, but only one (dead) beluga whale was found in lower Cook Inlet. Abundance estimates are being developed for this and other recent years. Introduction Beluga whales (Delphinapterus leucas) are distributed around most of Alaska from Yakutat to the Alaska/Yukon border (Hazañ 1988). Five stocks are recognized: Cook Inlet, Bristol Bay, Eastern Bering Sea, Eastern Chukchi Sea and the Beaufort Sea (Hill and DeMaster 1998; O'Corry-Crowe et al. 1997). The most isolated of these is the Cook Inlet stock, separated from the others by the Alaska Peninsula. Beluga whales in Cook Inlet are very concentrated in a few river mouths during parts of the year (as reviewed in Shelden 1994). The geographic and genetic isolation of the whales in Cook Inlet, in combination with their tendency towards site fidelity, makes this stock vulnerable to impacts from large or persistent harvests. The Alaska Regional Scientific Review Group (ASRG) "felt very strongly that every effort should be made to survey this population every year" (letter from L. Lowry, Chair of ASRG, to S. Pennoyer, NMFS, dated 13 }lday 1997). Since 1993, NOAA's National Marine Mammal Laboratory NI!ß4L) and its Alaska Regional Office have conducted annual aerial surveys to study the distribution and abundance of beluga whales in Cook Inlet (Withrow et al. 1994; Rugh et al. 1995, 1996, 1997a, 1997b) in cooperation with the Alaska Beluga Whale Commission (ABV/C) and the Cook Inlet Marine Mammal Council (CIMMC).