Abundance estimates for western North Pacific gray whales for use with stock structure hypotheses of the Range-wide Review of the Population Structure and Status of North Pacific gray whales
Justin G. Cooke
International Whaling Commission
Abundance estimates are derived for western North Pacific gray whales Eschrichtius robustus that correspond to the various stock structure hypotheses developed by the IWC Scientific Committee’s Range-wide Review of the Population Structure and Status of North Pacific gray whales (IWC 2018a), by fitting an individually-based population model to photo-id data and other data collected off Sakhalin, Kamchatka and Mexico. Abundance estimates are presented for the putative Western Feeding Group and Western Breeding Stock in 1995 and 2015. Abundance estimates for the Western Feeding Group in 2015 range from about 130 to about 300 whales (aged 1 yr and over) depending on stock structure hypothesis, while abundance estimates for the putative Western Breeding Stock are all less than 100.