Water districts ask judges to sort out steelhead and rainbow trout

By MATEUSZ PERKOWSKI

Capital Press

Several California irrigation districts want an appellate court to reverse a federal policy that differentiates between steelhead and rainbow trout under the Endangered Species Act.

The irrigation districts argue that steelhead, which are listed as either endangered or threatened in parts of the West Coast, should not be treated as a separate population from rainbow trout.

As defined by the Endangered Species Act, the two types of fish should be considered the same species -- Oncorhynchus mykiss -- because they're capable of breeding with one another, said Tim O'Laughlin, an attorney for the districts.

Plaintiffs in the case include the Modesto, Turlock, Merced, Oakdale and South San Joaquin irrigation districts as well as the Stockton East Water District.

A federal judge rejected their complaint against the federal government last year, but O'Laughlin asked the 9th U.S. Circuit Court of Appeals to reconsider that decision at a Dec. 11 hearing.

The primary difference between the two is that steelhead migrate from fresh water to the ocean, while rainbow trout stay in fresh water throughout their lives, according to court documents.

Steelhead are referred to as the anadromous form of the species, while rainbow trout are called the resident form.

The irrigation districts oppose a separate classification for steelhead because Endangered Species Act regulations can affect their water delivery operations.

The National Marine Fisheries Service considers steelhead a distinct population of the species that deserves federal protection, but the two life forms are visually indistinguishable in-stream, O'Laughlin said.

The districts worry that federal biologists may confuse rainbow trout with steelhead, resulting in unwarranted penalties or restrictions on irrigators, according to court documents.

"What we're asking for is an ESA policy that we can understand and apply on the ground that has a reasoned rationale behind it," said O'Laughlin.

The National Marine Fisheries Service does not believe the capacity for interbreeding between steelhead and rainbow trout should eliminate the distinction between the two.

The possibility of "reproductive exchange" does not preclude listing anadromous fish as a distinct population under the law, said Anna Katselas, an attorney for the agency.

"It's not a sensible interpretation at all," she said.

The classification may effectively allow NMFS to regulate a non-listed species, the rainbow trout, but that's within the agency's authority under the law, Katselas said.

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