Tribes seek boost in Oregon, California water flows to aid salmon

PORTLAND, Ore. (Reuters) - Two American Indian tribes asked the U.S. government to increase flows from dams to prevent the spread of a deadly fish disease that flourishes in warm water as trout and salmon suffer along the drought-parched West Coast.

Starting in about three weeks, a fall run of some 120,000 Chinook salmon is expected to swim up the Klamath River, which runs along the Oregon-California border, to their spawning beds, according to the Hoopa Valley Tribe and Yurok Tribe.

This week, both tribes asked the U.S. Bureau of Reclamation to increase flows from upstream dams, saying that doing so will give the fish a deeper, cooler channel to navigate at a crucial time in their migratory life cycle.

A spokeswoman for the agency said it could decide whether to boost stream flows within the next couple of weeks after weighing the advice of scientists.

Ichthyophthirius multifiliis, or "ich," was last measured in large quantities in the Klamath during a 2002 drought, when it may have killed many as 70,000 Chinook salmon and steelhead trout, said Michael Belchick, a biologist for the Yurok Tribe.

Spring runs of fish have fled warm upstream Klamath waters and gathered in cooler spring-fed creeks downstream, where ich has been proliferating.

"They sit in close proximity and pass ich from fish to fish," Belchick said, adding he worries fish could die off in similar numbers to the deaths of 2002. "What we're seeing could be catastrophic."

The native salmon and trout of the U.S. Northwest have been suffering under excessive heat and drought conditions, prompting officials to restrict fishing and to truck hatchery salmon more than a hundred miles (160 km) north to another facility.

In Washington state, some 5,400 rainbow trout at a fish hatchery north of Seattle died in the heat, the Bellingham Herald newspaper reported on Thursday, citing the state's Department of Fish and Wildlife.

Last month, Washington officials reported that more than a dozen state-operated fish hatcheries were experiencing low water levels or high water temperatures as a result of drought conditions.

The agency said it had lost about 1.5 million juvenile fish in 2015 and was using re-circulation pumps and aerators to reduce the effects of warm water temperatures at hatcheries.

It also said it was providing medicated feed to fish to combat fungal and bacterial infections triggered by heightened water temperatures.

(Additional reporting by Eric M. Johnson in Seattle; Editing by Eric Walsh)