Importance of the Alaskan Beaufort Sea to King Eiders

The king eider population appeared to remain stable between 1953 and 1976.  However a recent analysis of migration counts off Point Barrow, Alaska estimated that king eiders have declined 56% (3.9% per year) from approximately 802,556 birds in 1976 to about 350,835 in 1996 (Suydam et al. 2000).  King eiders migrate eastward along the Beaufort Sea during May-June to arctic nesting areas in Alaska and Canada.  During molt-migrations in late summer and fall-migration (September-August), eiders move westward along the Beaufort Sea coast to overwintering areas in the Chukchi and Bering Seas.  Although migration count data have been collected at Point Barrow intermittently since 1953, little information exists regarding the importance of the Beaufort Sea to king eiders in other locations.  Petroleum related exploration and development has the potential to affect king eider populations.   For example, the vulnerability of king eiders to an offshore oil spill was verified when at least 1,609 + 70 king eider carcasses were found on St. Paul Island following an oil spill February 1996.   Other effects could result from disturbance of resting or migrating flocks and death of individual birds due to strikes on offshore structures.  The first oil development in the Beaufort Sea (BPXA Northstar) started production in November 2001 and other developments are likely.  Additional information on patterns of migration and habitat use for king eiders in the Beaufort Sea would be useful for predicting the potential impact of petroleum related developments along the Beaufort Sea coastline.

5.   Test an extended life, implantable satellite transmitter that uses batteries developed for implantation in human applications; evaluate the potential for development of TDR (time-depth recorder) technology for use on king eiders; test TDR technology if feasible.

This study is envisioned as a jointly funded activity conducted by the University of Alaska Fish and Wildlife Cooperative Research Unit with key organizations potentially including: MMS, University of Alaska CMI, North Slope Borough, U.S. Fish and Wildlife Service, and Canadian Wildlife Service.  The study will use implanted satellite transmitters to evaluate habitat use patterns and locate the migration corridor for king eiders. Female king eiders (60 successful breeders and 60 unsuccessful breeders) and male king eiders (n = 60) will be instrumented with implanted satellite transmitters on their breeding grounds and monitored during periods when they undertake spring and fall migrations.  Satellite transmitters will also allow the opportunity to document the rates of migration across Beaufort Sea.  Develop and test an extended life, implantable satellite transmitter, and if feasible, TDR technology for use on king eiders.

Because basic biological parameters (i.e., population status, survival estimates, migration routes, and habitat requirements) for king eiders in the Beaufort Sea have been poorly described, assessment of potential impacts of offshore oil development are limited in regard to protecting the species.  Increased knowledge of this species could be incorporated with data being collected by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service to better assess impacts.

This study is on schedule and making satisfactory progress.  Preparations are underway for the 3^rd field season (2004).  To date, 33 adult king eiders have been instrumented with satellite transmitters.  King eiders staged in the Beaufort Sea before migrating southward to molt along the Chukotsk Peninsula and Kamchatka Peninsula of Russia, and in U.S. waters off St. Lawrence Island, and the Alaska Peninsula.

March 31, 2005 (CMI Final Report); 2007 (BRD Final Report)

Powell, A. N., L. M. Phillips, E. A. Rexstad and E. J. Taylor. 2004. Importance of the Alaska Beaufort Sea to King Eiders (Somateria spectabilis), p. 38-47 In University of Alaska Coastal Marine Institute Annual Report No. 10. OCS Study MMS 2004-002, University of Alaska Fairbanks and USDOI, MMS, Alaska OCS Region, 119 p.

cmi@sfos.uaf.edu

April 2004