Barlow and Forney: Abundance and population density of cetaceans in the California Current ecosystem 



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Table 8 



Number of sightings (n I and estimated abundance (A^) for each species in the Oregon-Washington region for the years 1996, 2001. 

 and 2005. The total lengths of transects surveyed were 4336, 3100. and 2525 km for these years, respectively, in Beaufort sea 

 state of 5 or less and were 532, 380, and 292 km, respectively, for Beaufort sea state of 2 or less. Unidentified large whales and 

 small whales were not sufficiently specified to be included in the subtotals. 



survey periods, and a more detailed study of trends in 

 fin whale abundance is warranted. 



Bryde's and sei whales are very rare off the U.S. 

 west coast, and minke whales are not common, par- 

 ticularly in offshore waters. Bryde's whales are com- 

 monly viewed as tropical baleen whales and therefore 

 their low abundance is expected. However, sei whales 

 were previously harvested commercially along the west 

 coast by coastal whaling stations, and their near ab- 

 sence is more of a mystery. Minke whales are known 



to be common in some nearshore areas (Stern, 1992), 

 which were not well sampled during our broad-scale 

 cruises, but overall densities were low. Minke whale 

 densities may have been underestimated in the study 

 area because trackline detection probabilities were not 

 directly estimated. There are no previous estimates of 

 g(Q) for minke whales based on observers searching 

 with 25x binoculars. Skaug et al. (2004) used observ- 

 ers searching with naked eyes and estimated g^O) 

 values between approximately 0.7 in Beaufort 1 and 



