FRIDAY, HARBOR WASHINGTON – With two new deaths this year and no new calves since 2012, the population of endangered killer whales in the Puget Sound continues to decline.
The number of whales in the J, K and L pods has dropped to 78, a level not seen since 1985, according to a census by the Center for Whale Research. Adding to the concerns, the whales appear to be “splintering” from their pods, which are their basic social groups.
Among killer whales, offspring tend to stay with their mothers for life, sustaining identifiable “matrilines” that typically contain youngsters, their mothers and their grandmothers. So far, the matrilines have stayed together, though many of these groups are now smaller.
The primary factor for the population decline appears to be a lack of food for the killer whales, which generally prey on chinook salmon passing through the San Juan Islands on the way back to Canada’s Fraser River. The whales have a strong preference for chinook, typically larger and fatter fish, but they will eat other species of salmon and even other fish sometimes.
During the 1960s and early 1970s, the Southern Resident population was reduced dramatically when orcas were captured for marine parks and aquariums throughout the world. After that practice ended, their numbers grew to 98 in 1995, then dropped to 80 in ,2001 the year the whales were proposed for listing under the Endangered Species Act.
Since then, their population has gone up and down by a few whales each year, dropping from 88 in 2011 to 78 today.