Dwindling Food Supplies, Climate Change Threaten Orcas’ Future

by Vins
Published: Updated:

One of the biggest causes for the disappearance of orcas in the Puget Sound region is a dwindling food supply and abnormal activity, Dahr Jamail reports for Truthout. Jamail reports on the research of Dr. Paul Spong, who has devoted four decades of his life to studying orca’s lifestyle. Spong’s OrcaLab, based in British Columbia, operates on the philosophy that it is possible to study wildlife without interfering with the lives or habitat of the wildlife being studied. They accomplish this feat using hydrophones they position around the orcas, which allow them to monitor the whales’ movements continuously over an area of fifty square kilometers. OrcaLab’s stated goals are OrcaLab to work towards the “preservation of orca habitat; release and rehabilitation of captive cetaceans … and bringing to an end the dismal era of commercial whaling.”

According to Spong, the small population or orcas is due to ship and boat noise, seismic exploration, military sonar, and a dramatic increase in large vessel traffic in the area. The biggest issue with the orcas is the loss of food supply. Researchers have found that orcas have very specific diets. Their preferred food choice is Chinook salmon and chum, which have declined in recent decades—with direct impacts on the whales. Furthermore, Howard Garrett, the board president of orca Network, told Jamail, “Naval training exercises likely negatively impact orcas, and ship noises may mask their echolocation and communication, impairing their ability to find and catch salmon.”

Climate disruption is another factor in depletion of the orca population. “The principle problem for orcas is climate change,” Spong said. “Ocean temperature changes impact food supply.” Increased water temperatures reduce the survival of salmon. The 1995-96 El Niño correlated with a twenty percent drop in the Puget Sound orca population, from 1996 and 2001.

Nevertheless, Jamail reports, Garrett and Spong find hope in potential remedies that could save the Puget Sound orcas. Both advocate removing dams that thwart salmon migration. According to Spong, “If there is any hope in recovering these orca populations, there must be an effort to boost their food supply by working towards taking down dams in rivers where salmon spawn.”

Source: Dahr Jamail, “Without Major Interventions, the Orca’s Days Are Numbered,” Truthout, November 30, 2016, http://www.truth-out.org/news/item/38543-without-major-interventions-the-orca-s-days-are-numbered

Student Researcher: Jared English (Sonoma State University)

Faculty Evaluator: Jerald Krause (Sonoma State University)