Last month, biologists warned killer whales’ existence is being threatened by California water issues that negatively affect salmon populations. Specifically endangered are the southern resident orcas that live in Puget Sound but have been seen as far south as Monterey Bay since 2000. There are 83 southern resident killer whales.
At blame is water diversion from the Delta. According to the Silicon Valley Mercury News:
In a draft scientific report, biologists conclude the damage that water operations are doing to California’s salmon populations is enough to threaten the orcas’ existence since they depend on salmon for food…The findings, contained in a draft report by the agency’s scientists, could elevate public support for environmental protection in the Delta, where the conflict between environmental advocates and water users has centered on Delta smelt, a nondescript fish that grows a couple of inches long and smells like cucumbers…Biologists last month reported tentatively that pumping water out of the Delta threatens to drive spring-run chinook salmon and winter-run chinook salmon extinct.
Last year, the collapse of Sacramento River chinook salmon fall-run not only closed commercial fishing season off the coast of California and Oregon, but it also caused the orcas to turn around. Southern resident orcas’ diet consists mostly of salmon eating about 500,000 pounds a year (80% chinook). In the winter, the whales move up and down the coast looking for food. For the last seven years, California salmon have provided an important food source for the whales. This winter, the orcas swam about halfway down the coast of Oregon, then turned around due to lack of salmon to nourish the population.