by: Chris Legeros Updated:
SEATTLE - The number of resident orcas in Puget Sound has dropped by 20 percent since the 1990s. Only 80 remain.
One reason they aren't bouncing back are declining runs of their favorite food source, Chinook salmon.
Since they favor fish coming from the Fraser River in Canada, the Washington government is talking with Canada to make sure killer whales get enough to eat. Lynne Barre is with NOAA Fisheries.
“We’re working together to see what we can do to really support recovery,” she said.
With tagging and GPS tracking, scientists now say the orcas travel as far south as Calfornia to feed and at times they compete for food with seals, sea lions and other orcas.
Their bodies are also plagued by pollution.
“The Southern resident killer whales are some of the most contaminated marine mammals on the planet,” Barre said.
Toxic chemicals have made them sick and hindered their ability to reproduce. Some compounds like PCBs (polychlorinated biphenyls) and DDT (Dichlorodiphenyl-trichloro-ethene) we don’t even use anymore, but they got into the water years ago and were carried by fish up the food chain.
“We’re still working on ways to mitigate those inputs into the environment,” said Barre.
Scientists report boat noise has forced whales to hunt less and travel more. Rules were put into effect in 2011 to keep vessels at least 200 yards away.
Since then, whale watching boats have mostly complied, but many recreational boaters are ignoring the rules.
“We’re hopeful that extra enforcement and education is going to improve compliance,” Barre said.