|Document Type:||Journal Article|
|Title:||Assessing the coastal occurrence of endangered killer whales using autonomous passive acoustic recorders|
|Author:||M. B. Hanson, Candice K. Emmons, E. J. Ward, Jeffrey A. Nystuen, Marc O. Lammers|
|Journal:||Journal of the Acoustical Society of America|
|Keywords:||killer whale,Chinook salmon,autonomous acoustic recorders|
Using moored autonomous acoustic recorders to detect and record the vocalizations of social odonotocetes to determine their occurrence patterns is an important new non-invasive tool in the study of these species in remote locations. We deployed acoustic recorders in seven locations on the continental shelf of the U.S. west coast from Cape Flattery, Washington to Pt. Reyes, California to detect and record endangered southern resident killer whales between January and June of 2006-2011. Detection rates of these whales were greater in 2009 and 2011 than in 2006-2008, were most common in the month of March, and occurred with the greatest frequency off the Columbia River and Westport. The high values in detection rates off the Columbia River and Westport in March was likely related to the presence of their most commonly consumed prey, Chinook salmon. We suggest that the observed patterns of annual and monthly ocurrence were related to run strength and run timing, respectively, for spring Chinook returning to the Columbia River, the largest run in this region at this time of year. Acoustic recorders provided a unique, long-term, dataset that will be important to inform future consideration of Critical habitat designationfor this ESA listed species.
|Theme:||Habitats to Support Sustainable Fisheries and Recovered Populations|
Develop methods, in collaboration with ocean users, to reduce/eliminate fishing gear and other anthropogenic impacts on habitat .