June 15, 2020 — The following was released by NOAA Fisheries:
This is the time of year when boats multiply on the inland waters of Washington as more people get outdoors for the summer. It is also the time when many long for a precious chance to see the endangered Southern Resident killer whales.
Boats generate noise, though, which—combined with the boat traffic itself—is considered one of the main threats to the Southern Residents. It can interfere with the whales’ use of echolocation, a form of sonar they use to find the Chinook salmon they favor as prey. Regardless of how many salmon might be available, noise can make it harder for the whales to find them.
That can be particularly costly for the Southern Residents because salmon do not gather in schools as some fish do. The whales must find each one individually—painstakingly hunting one fish at a time.