The Associated Press has an interesting piece out on the southern orcas of Puget Sound that were the trigger for a lawsuit challenging that Southeast Alaska trolling boats king salmon harvests have affected the endangered killer whales for a lack of salmon to consume. Here’s the AP with some details on just what might be affecting the whales:
They’ve filed a lawsuit seeking to halt Southeast Alaska’s king salmon trolling season,claiming it threatens the the orcas’ most important food. They’ve breached dikes and removed dams to create wetland habitat for kings. They’ve limited commercial fishing to try to ensure prey for the whales. They’ve made boats slow down and keep farther away from the animals to reduce their stress and to quiet the waters so they can better hunt.
So far, those efforts have had limited success, and research published Monday in the journal Nature Ecology and Evolution suggests why: The whales are so inbred that they are dying younger and their population is not recovering. Female killer whales take about 20 years to reach peak fertility, and the females may not be living long enough to ensure the growth of their population.
While that news sounds grim for the revered orcas — known as the “southern resident” killer whales — it also underscores the urgency of conservation efforts, said Kim Parsons, a geneticist with the National Oceanic and Atmospheric Administration’s NOAA Fisheries who co-authored the study. The population is not necessarily doomed, she said.
“It’s not often inbreeding itself that will result in a shortened lifespan or kill an individual,” Parsons said. “It’s really that inbreeding makes these individuals more vulnerable to disease or environmental factors. We can support the population by supporting the environment and giving them the best chance possible.”