Daily Archives: April 14, 2010

Orcas and salmon in new Cascadia Scorecard

The Sightline Institute has just released a new Cascadia Scorecard that attempts to track progress towards sustainability in Cascadia, the ecoregion encompassing much of western Washington and southern British Columbia. Southern resident killer whales and chinook salmon are featured within the scorecard’s wildlife indicator along with wolves, sage grouse, and caribou. While the wolf population has grown recently, most trends are uncertain or variable, and on average the five wildlife species are at only 16% of their historic abundance.

Below are two graphs from the scorecard, one showing southern resident pod population trends, the other total chinook returns to the Bonneville Dam on the lower Columbia River. 

In an associated “Orca Update” released today, Lisa Stiffler analyzes some of the details in these trends.  She makes some interesting connections between SRKWs, west coast chinook stocks, and Pacific climate conditions.  It remains clear to me that we need to delve deeper into the salmon and orca population dynamics (beyond Ford et al., 2005 and Hanson et al., 2010), as well the potential influence of El Nino vs La Nina conditions on the Northeast Pacific.  Lisa also included a nice rendering of the most-recent official population time series:

Data Sources for the Wildlife Indicator

Orcas. Refers to “southern resident” population, unless otherwise noted. Population data from Ken Balcomb, senior scientist, The Center for Whale Research, http://www.whaleresearch.com. Historical abundance derived from Washington Department of Fish and Wildlife, Washington State Status Report for the Killer Whale, Appendix A, March 2004, page 41, http://wdfw.wa.gov/wlm/diversty/soc/status/orca/final_orca_status.pdf.

Salmon. Refers to spring and summer chinook salmon at the Bonneville Dam, unless otherwise noted. Population data from University of Washington, School of Aquatic and Fisheries Science, Columbia River DART database, “Adult Passage Annual Summary,” http://www.cbr.washington.edu/dart/adult_annual.html. Historical abundance from US National Marine Fisheries Service, Northwest Fisheries Science Center, “Final Report of Updated Status of Listed ESUs of Salmon and Steelhead,” http://www.nwfsc.noaa.gov/trt/brtrpt.htm.