1999 to 2002 Beluga Whale Satellite-Tagging and Health Assessments in Cook Inlet Alaska
April 16, 2002
Beluga whales, Delphinapterus leucas, live year-round in arctic and subarctic seas of the Northern Hemisphere (Hazard 1988). In Alaska waters, belugas spend summer in different regions of Alaska (Frost and Lowry 1990) to the extent that genetic differentiation has occurred within the species (O’Corry-Crow et al. 1997). These summering populations are found in Cook Inlet, Bristol Bay, the eastern Bering Sea, the eastern Chukchi Sea, and the eastern Beaufort Sea (Fig. 1). For Cook Inlet, both geographic and genetic isolation from the other beluga populations in Alaska has resulted in evident genetic drift (O’Corry-Crowe et al. 1997, 2010). While some of these Alaska populations are migratory, covering 1,000s of kilometers between summering and wintering regions, most Cook Inlet belugas remain year-round within the boundaries of the inlet.
The National Marine Fisheries Service (NMFS) began monitoring the Cook Inlet population in the 1990s, following consideration for listing (assigning Candidate Species status) under the U.S. Endangered Species Act (ESA) in 1988 (Shelden et al. 2015). Prior to this, the State of Alaska and Alaska Department of Fish and Game had conducted aerial surveys in the 1960s, late 1970s, and early 1980s (Shelden et al. 2015). The surveys in the late 1970s were the first attempt to document seasonal distribution of the Cook Inlet population. While informative, aerial studies were limited by range of the aircraft and inclement weather, particularly during the winter months. By the early 1990s, Canadian scientists were successfully attaching satellite-linked transmitters to the dorsal ridges of belugas (Martin and Smith 1992). These devices allowed scientists to track the daily movements of the whales. NMFS scientists worked with the Canadian scientists and Cook Inlet native subsistence hunters to develop a tagging program for Cook Inlet (Ferrero et al. 2000).
Capture and satellite-tagging of Cook Inlet belugas was first attempted in July 1995 (Ferrero et al. 2000). After two seasons of experimenting with capture techniques (1995 and 1997), successful attachment of a satellite-linked transmitter to a juvenile male beluga occurred in late May 1999 (Ferrero et al. 2000). This whale’s movements were followed through the summer months until the last satellite uplink was received on September 17, 1999 (Ferrero et al. 2000, Shelden et al. 2015). With this success, future tagging efforts were planned for late summer to attempt to document autumn and winter movements of Cook Inlet belugas.