paper. The 1976-77 research seasons man. 1980. Spring migration of the west­ 1978. Rep Int Whalmg Comm 30"405-413 were funded by the Bureau of Land ern Arctic population of bowhead whales. Mar. Cook, J. 1926 Pursumg the whale, a quarter Fish. Rev. 42(9-10):36-46. century of whaling in the Arctic. Houghton Management under the Outer Continen­ ____, B. Krogman, J. Johnson, W Mar­ Mifflin Co., Boston, 344 p. tal Shelf Environmental Assessment quette, D. Rugh, R. Sonntag, T. Bray, J. Dahl heim, M., T. Bray, and H. Braham. Brueggeman, M. Dahlheim, M. Nerini, and S. 1980. Vessel survey for bowhead whales in Program office, NOAA, Juneau, Savage. 1980. Population studies of the the Bering and Chukchi Seas, June-july Alaska; 1978-79 seasons were funded bowhead whale (Balaena mysticetus): Prelimi­ 1978. Mar. Fish. Rev. 42(9-10):51-57. through NOAA's expanded Bowhead nary results of the 1979 spring research sea­ Marko, J. R. 1975. Satellite observations of son. Rep. Int. Whaling Comm. 30:391-404. the Beaufort Sea ice cover. Dep. Environ., Whale Research Program. ____, , S. Leatherwood, W. Victoria, B.C., Beaufort Sea Tech. Rep. 34, Marquette, D. Rugh, M. Tillman, J. Johnson, 137 p. and G. Carroll. 1979. Preliminary report Rugh, D. J., and J. C. Cubbage. 1980. Migra­ Literature Cited of the 1978 spring bowhead whale research tion of bowhead whales past Cape Lisburne, program results. Rep. [nt. Whaling Comm. Alaska. Mar. Fish. Rev. 42(9-10):46-51. Bailey, A. M., and R. W Hendee. 29:291-306 Townsend, C. H. J935. The distribution of 1926. Notes on the mammals of northwestern ____, , M. Nerini, D. Rugh, W. certain whales as shown by logbook records of Alaska. J. Mammal. 7:9-28. Marquette, and J. Johnson. 1980. Re­ American whaleships. Zoologica (N.Y.) 19, Braham, H. w., M. A. Fraker, and B. D. Krog- search on bowhead whales. June-December 50 p. Townsend (1935) plotted the loca­ tions of bowheads killed by Yankee whalers operating in the Bering Sea and Spring Migration of the Western Arctic Ocean from 1848 to 1919. His Arctic Population of Bowhead Whales map suggests that bowheads may have formerly occurred in the Bering and Chukchi Seas, as well as in the Beaufort HOWARD W. BRAHAM, MARK A. FRAKER, and BRUCE D. KROGMAN Sea, during the summer months, well beyond the present-day whaling sea­ son. Data collected since 1974, how­ ever, indicate that bowheads do occur in the eastern Beaufort Sea during the Introduction for example, present-day whal ing oc­ summer (Fraker and Bockstoce, 1980), Each spring the western Arctic popu­ curs from approximately the first week but that probably only a few occur in the lation of bowhead whales, Sa/aena in April to about the first week in May; Bering and southern Chukchi Seas dur­ mysticetus, migrates from the Bering at Barrow, Alaska, the peak of both ing summer (Braham et aI., footnote 3; Sea, through the Chukchi Sea, and into migration and whaling activity occurs Braham, Krogman, Nerini, Rugh, the Beaufort Sea. For centuries, coastal from the last week in April to the last Marquette, and Johnson, 1980; Dahl­ Eskimos of western Alaska and eastern week in May (Braham and Krogman!; heim et aI., 1980). 2 Siberia have taken bowheads during Marquette , 1979; Braham et aI., 1979; Although the general timing and pat­ spring as the whales moved past their Braham et al. 3). tern of movements of bowheads during villages soon after openings formed in the spring migration are known (Bailey the pack ice. Traditionally, Eskimos and Hendee, 1926; Tomilin, 1957; 4 5 sailed or paddled their boats out into Foote ; Durham ; McVay, 1973; I Braham, H.. and B. Krogman. 1977. Population cracks and open water areas in the ice, biology of the bowhead (Balaeno mysticetus) and Braham and Krogman; footnote 1), the called leads and polynyas, respectively, beluga (Delphinopterus leucos) whale in the Be­ precise pathway that they take has not ring, Chukchi and Beaufort Seas. Processed rep., been fully described-especially in the from April to June to hunt the whales. 29 p. Natl. Mar. Mammal Lab., NOAA, 7600 The breakup of the pack ice and migra­ Sand Point Way N.E., Bldg. 32, Seattle, WA largely frozen Beaufort Sea. In this tion pattern of the whales are so regular 98115. paper we discuss the spring migration 2Marquette, W. M 1977 The 1976 catch of that the whales are reliably accessible to bowhead whales (Balaenu myslicetus) by Alas­ route, March through June, and de­ whalers each spring, but only for a few kan Eskimos, with a review of the fishery, 1973­ scribe ice conditions encountered by weeks. AtSt. Lawrence Island, Alaska, 1976, and a biological summary of the species. the whales. In addition to gaining an Processed rep., 80 p. Natl. Mar. Mammal Lab., NOAA, 7600 Sand Point Way N.E., Bldg. 32, understanding of an important part of Seattle, WA 98115. 3Braham, H., B. Krogman, andG. Carroll. 1979. Howard W. Braham and Bruce D. Krogman are Population biology of the bowhead whale with the National Marine Mammal Laboratory, (Balaena mysticetus) II: Migration, distribution, 'Foote, D. C. 1964. Observations of the bowhead Northwest and Alaska Fisheries Center, National and abundance in the Bering, Chukchi, and whale at Point Hope, Alaska. Unpubl. manuscr., Marine Fisheries Service, NOAA, 7600 Sand Beaufort Seas, with notes on the distribution of 73 p. McGill Univ., Montreal, Quebec, Can. Point Way N.E., Bldg. 32, Seattle, WA 98115. white whales (Delphinuplerus leucas). Unpubl. "Durham, F. E. 1972. Biology of the bowhead Mark A. Fraker is with LGL Limited, Environ­ final rep., OCSEAP Contract No. R7 120807 , 118 whale (Balaena mysticelus) in the western arctic. mental Research Associates, 2453 Beacon Av­ p. Natl. Mar. Mammal Lab., NOAA, 7600 Sand Unpubl. manuscr., 93 p. Dep. BioI., Univ. South. enue, Sidney, B.C. V8L IX7, Canada. Point Way N.E., Bldg. 32, Seattle, WA 98115. Calif., Los Angeles, CA 90007. 36 Marine Fisheries Review the species' annual cycle of move­ Second, a general westward drift of most often a DeHaviliand Twin-OtterS ments, the primary objective of our ice in the eastern Beaufort Sea results in and a Grumman Goose (N780) equip­ study of migration and distribution is to extensive lead and polynya develop­ ped with Global Navigation 500 naviga­ determine what portion of the bowhead ment in the eastern portion of the study tional equipment. FI ights were either population migrates past the National area. Easterly winds in the eastern systematic or opportunistic depending Marine Fisheries Service whale­ Beaufort Sea during spring, in concert on the extent of ice cover, weather, and counting ice camps, described by with the clockwise rotation of the survey location. For detailed accounts Braham et a!. (1979) and Krogman Beaufort gyre, cause a major north­ of equipment, survey designs, and (1980), to ensure the best possible esti­ south lead west of Banks Island and methods, see Braham and Krogman mate of the population size. another (often connected) lead north of (footnote I); Braham et a!. (footnote 3, the landfast ice of the Tuktoyaktuk 1979); Braham, Krogman, Nerini, Study Area and Ice Conditions Peninsula (Fig. 3). During spring, the Rugh, Marquette, and Johnson (1980); The study area included the northern ice in Amundsen Gulf begins to break Fraker et a!. (1978); and Fraker (1979). Bering Sea, the Chukchi Sea east of up to form a major polynya, which ex­ long. 171 oW, and the Beaufort Sea and pands and becomes continuous with the Spring Migration Amundsen Gulf west of approximately leads off Banks Island and the Tuk­ long. 120 0 W (Fig. I). toyaktuk Peninsula. Migration Routes and Timing Ice is a dominant feature of the study Sources of Data During average ice years, bowhead area and a knowledge of its characteris­ whales spend the winter (January to The major sources of data for this tics is critical to understanding March) in the pack ice from St. Law­ paper were aerial surveys and compila­ bowhead migration. In March or April, rence Island south to St. Matthew Is­ tions of sightings by NMFS scientists the pack ice reaches its maximum ex­ land (Braham et al., footnote 3; Brueg­ working in the Bering, Chukchi, and tent in the Bering Sea (Shapiro and geman, footnote 6). During years when western Beaufort Seas 1976-79 Burns, 1975). Ice breakup begins as the pack ice is extensive, such as in (Braham and Krogman, footnote I; temperatures rise and wind direction 1976 and 1977, the whales can occur as Braham et al., 1979, footnote 3; Brueg­ shifts from northeast to south or south­ far south as the Pribilof Islands. Only geman6 ) and by Fraker in the eastern west, pushing the ice northward. In the two bowheads have been sighted in Beaufort Sea (Fraker et a!., 1978; northwestern Bering Sea, between the open water south of the ice front in the Fraker, 1979). Additional data on loca­ Chukchi Peninsula and St. Lawrence spring (Fig. 4). tion and timing of bowhead movements Island, strong currents further help to Aerial survey data collected since were also obtained from village resi­ break up the ice and form an open-water 1976 reveal that the bowhead migration dents along Alaska's northwest coast; corridor. North of the Bering Strait, a begins in the western part of the north­ observers at land and ice camps in shear or flaw zone forms parallel to the ern Bering Sea. From the area west of northwest Alaska (Braham and Krog­ Alaskan coast causing numerous small St. Matthew Island and southwest of St. man, footnote I; Braham et a!., 1979); leads to develop along and near this Lawrence Island, bowhead whales researchers on the NOAA ship Sur­ zone.