A federal court in San Francisco has rejected an appeal by three California growers who claimed the U.S. Fish and Wildlife Service overreached its authority when it cut water allocations to protect a fish species.

Reduced exports of Sacramento-San Joaquin River Delta water have been in effect since 2009. Prior pumping volumes threatened the Delta smelt with extinction, according to the USFWS. It’s one of several declining or endangered fish populations in California.

Attorneys for San Joaquin Valley growers Stewart & Jasper Orchards; Arroyo Farms; and King Pistachio Grove argued that applying the Endangered Species Act to the smelt violates the commerce clause in the federal constitution, court records show.

But the Ninth Circuit U.S. Court of Appeals upheld a district court ruling that the policy is constitutional.

Pacific Legal Foundation — which represents the growers — argued that the commerce clause limits federal regulation to interstate commerce, and that the smelt does not exist outside California and is not bought or sold.

Among other things, the ruling handed down March 25 by Judge Sidney Tho-mas on behalf of the circuit court cited a precedent affirming the commercial value of travel by researchers and naturalists to study species limited to one area.

On a separate issue, Thomas and his colleagues overturned the district court’s ruling that the growers lack standing to bring a case under section nine of the Endangered Species Act.

Attorney Brandon Middleton said the PLF is considering an appeal to the U.S. Supreme Court.

“If a regulation is valid simply because it has some hypothetical tie to interstate commerce … there’s no stopping point,” Middleton said in a news release.