Synthesis of Available Information on the Cook Inlet Stock of Beluga Whales
AFSC Processed Report 99-06: Compilation of information from the status review, scientific review, abundance estimate and workshop on Cook Inlet belugas.
On 19 November 1998, NOAA Fisheries initiated a status review of the Cook Inlet beluga whale (Delphinapterus leucas) stock to determine whether designation under the Marine Mammal Protection Act or a change in listing classification under the U.S. Endangered Species Act was warranted (63 FR 64229; 19 Nov. 1998). NOAA Fisheries undertook a review in conjunction with the Alaska Beluga Whale Committee and the Cook Inlet Marine Mammal Council. The status review consisted of a period (19 November 1998 to 19 January 1999) wherein NOAA Fisheries requested public comment and pertinent information, followed by a workshop for presentation of scientific information and the collection of additional public comments held 8-9 March 1999 in Anchorage, Alaska. The scientific review was focused on the current status of Cook Inlet belugas: distribution, abundance, trends in abundance, and habitat. The effects of the Alaska Native subsistence harvest and the potential effects of other anthropogenic impacts, as well as beluga natural mortality, were also examined. Results of the scientific review confirm that this stock of beluga whales is geographically and genetically isolated from all other stocks. It is now evident that their distribution within Cook Inlet is shrinking, and that there are no large, persistent groups of beluga whales in the Gulf of Alaska. Habitat factors are being examined, including physical, ecosystem and anthropogenic factors. Samples from belugas in Cook Inlet had lower contaminant and heavy metal levels (except copper) than did other stocks of belugas in Alaska. The abundance of beluga whales in Cook Inlet has declined by nearly 50% between 1994 and 1998. The latest abundance estimate, from the June 1998 aerial counts, was 347 whales (SE = 101, CV = 0.29). This estimate includes corrections for surface timings (calculated from suction-cup attached VHF transmitters) and sighting rates (calculated from video analysis). An annual take of approximately 72 whales (averaged for the years 1994-96) has been excessive for this small stock. Options for reducing the harvest levels and increasing the efficiency of the hunt are being developed in cooperation with local hunters.