SANTA ROSA, Calif. (AP) -- A group of environmentalists, fishermen and Karuk tribe members filed suit Thursday to force the regional water board to regulate discharges of highly toxic algae in the Klamath River.

The lawsuit filed in Sonoma County Superior Court alleges that the North Coast Regional Quality Control Board has failed to establish limits on discharges from California dams and reservoirs owned by Portland, Ore.-based PacifiCorp.

The plaintiffs - the Klamath Riverkeeper, the Karuk tribe of California and the Pacific Coast Federation of Fishermen's Associations - have long pushed for removal of the Iron Gate and Copco dams, which they claim harms water quality and salmon runs in the river along the California-Oregon border.

Earlier this year, the groups petitioned the regional water board to regulate PacifiCorp's discharges, but the board said it lacked the authority to regulate the company - a claim the plaintiffs dispute in Thursday's lawsuit.

Water board officials did not immediately return calls for comment Thursday.

Last week, a federal judge in San Francisco ruled that a separate lawsuit filed against PacifiCorp could go forward.

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