SEATTLE -- A new U.S. lawsuit filed Monday seeks to establish a whale protection zone for endangered orcas in the Pacific Northwest.
The Center for Biological Diversity and the Orca Relief Citizens' Alliance sued NOAA Fisheries in U.S. District Court in Seattle, saying the agency has failed to act on a petition it filed in 2016.
The petition sought to bar vessels from a 10- to 12-square-mile (26- to 31-square-kilometer) area west of San Juan Island where the orcas, called southern resident killer whales, feed from April through September each year. Any vessels exempted from the ban would be required to abide by a "no wake" rule in the zone.
Researchers say the whales have been largely missing from their usual summer feeding grounds this year, apparently because their preferred prey — Chinook salmon — have been so scarce.
Canada has already announced that no vessel traffic will be allowed from June through October in three sanctuary zones in prime orca feeding habitat, and Washington state has adopted new restrictions requiring boats to keep at least 300 yards (274 meters) away from the animals.
"Southern Residents need more salmon and better protection throughout their range," Julie Teel Simmonds, an attorney with the center, said in a written statement. "But let's start by giving them the peace and quiet they need to find food in the Salish Sea."
NOAA Fisheries did not have any immediate comment on the lawsuit, said spokesman Michael Milstein. The complaint seeks to have the agency respond to the petition by Dec. 19.
The whales have been struggling with a dearth of Chinook as well as pollution and vessel noise, which advocates say hinders the echolocation they use to hunt.
The Center for Whale Research, which monitors the orcas, announced this month that three more have recently gone missing and are presumed dead, bringing the remaining population to 73 whales — the lowest number since the mid-1970s, when dozens were captured for display at marine parks around the world.
The lawsuit is the third in the past year that the Center for Biological Diversity has filed seeking better protection of the whales.
The earlier cases seek to expand designated critical habitat for the whales into the waters off Washington, Oregon and California where the whales forage in the late fall, winter and early spring, and to ensure that managers of Pacific salmon fisheries minimize the impacts on the whales.
In response, the federal government has announced that by October it will propose expanded habitat protections off the Pacific coast, and that by next May it will issue an updated analysis about the extent to which salmon fishing is harming the orcas.