Gray whale photographic identification in 1997

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Calambokidis, J., L. Schlender, M. Gosho, and P. Gearin. 1998. Gray whale photographic identification in 1997Final Report to the National Marine Mammal Laboratory, Seattle, WA.


Photographic identification of gray whales in Washington State was conducted in 1997 by Cascadia Research and the National Marine Mammal Laboratory. This has been part of an ongoing research effort to study the abundance, movements, residence times, and return rate of gray whales that feed in Washington waters for extended periods. This report provides a brief summary of activities and in 1997 and preliminary results.

A total of 42 surveys were conducted by Cascadia personnel between 15 March and 10 August 1997 in Washington State. Identification photographs were also provided by the National Marine Mammal Laboratory from 47 surveys conducted from 31 May to 8 October 1997 in the western Strait of Juan de Fuca and the northern Washington coast. Individual gray whales were successfully identified on 178 occasions by Cascadia and NMML in 1997 (including one contributed photograph).

Thirty-seven different gray whales were identified primarily on the northern coast of Washington State and near the western entrance to the Strait of Juan de Fuca. Gray whales again spent little time in Puget Sound in 1997. Excluding seven suspected early-season migratory animals, 25 of 30 (83%) of the whales identified had been seen in past years. The total number of gray whales identified in the course of the study since 1984 now is 168. Individual gray whales were identified from one to 16 times each and extending over 100 days for two animals. Movements of animals in 1997 were commonly seen between the Washington outer coast and the Strait of Juan de Fuca and between these areas and southern British Columbia. Little interchange (even between years) has been seen between Puget Sound and other regions.