Orcas in Washington state waters will be counted and studied over the next nine months to determine whether they need to continue to be listed under the federal Endangered Species Act, the National Oceanic and Atmospheric Administration in Seattle announced Monday.

The federal listing is being challenged by an activist California-based law firm and two of its clients. The Pacific Legal Foundation, based in Sacramento, Calif., with an office in Bellevue, and two large farms in California’s San Joaquin Valley are asking that the orcas be removed from the federal endangered species list.

The Center for Environmental Science, Accuracy and Reliability, based in Gold River, Calif., near Sacramento, worked with the groups on the 62-page petition.

The fact the petition will be reviewed does not mean orcas will be taken off the list, said Brian Gorman, a NOAA spokesman for the Seattle office, which is handling the request.

The agency has until next August to make a determination, Gorman said. If it decides delisting is warranted, the public would have a chance to comment before a decision is made.

“We go through a series of steps, each of which is a little bit tighter than the preceding one,” he said.

The endangered status of the state’s orcas has been given by government officials as a reason for restrictions on the amount of water available for irrigation from California rivers because they bear salmon that migrate north to Washington state waters where they form part of the orcas’ diet, said Damien Schiff, an attorney for the Pacific Legal Foundation in Sacramento.

The California farms seeking the change in orca status are Empresas del Bosque in Fresno and Merced counties and Coburn Ranch near Dos Palos. Both rely on water from the Sacramento and San Joaquin river systems, Schiff said.

“New genetic analyses done since 2010 show that the orca whales (in Western Washington waters) are not genetically distinct from orca whales anywhere else in the world,” he said.

The orcas were listed in 2005 as endangered under the federal Endangered Species Act. The listing covers three pods of orcas living in the Salish Sea between the southern end of Puget Sound and the Strait of Georgia in British Columbia. At the time of the listing, the pods numbered 89 orcas. Now there are 86, according to NOAA.

The orcas landed on the endangered list two years after region’s chinook salmon were listed as threatened under the same federal law.

Just a few years earlier, NOAA had turned down requests to list the orcas, using the same arguments that the petitioners are using today — that the populations are not genetically distinct, Gorman said. After losing a court battle in 2003, NOAA researched the issue further and found that the Washington state orcas were biologically and socially distinct from neighboring populations, he said.

“This killer whale population doesn’t seem to interbreed with any other,” Gorman said.

Schiff of the Pacific Legal Foundation said that in addition to the orca listing’s effect on the farms, “often times the law is used inappropriately to injure private property rights and other individual liberties and one way to keep this from happening is to make sure the decisions are based on the best possible science.”

The firm also has filed separate suits over Obamacare and numerous other environmental regulations, according to its website.

“We’re an action organization, battling in courtrooms across the country for limited government, property rights, free enterprise, and common sense in environmental regulations,” the website says.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.