Coho salmon migrating toward the ocean this week were killed by a sudden water-level drop in a Russian River tributary near Healdsburg, the result of efforts to protect crops from frost, officials said.
The deaths of the endangered sal-mon add urgency to a multi-agency task force meeting, scheduled Tuesday in Sacramento, aimed at finding ways to protect crops from frost while preserving threatened and endangered fish in the Russian River and its tributaries.
"We are very concerned about the situation," said Dan Torquemada, a special agent with the National Marine Fisheries Service.
His agency's law enforcement arm, the state Attorney General and the Sonoma County District Attorney's Office are investigating this week's fish deaths and are giving no further details, he said.
Tuesday's meeting in Sacramento before the state Water Resources Control Board stems from another fish kill under similar circumstances last year, one the federal fisheries agency had predicted would be repeated this year.
When freezing temperatures hit the North Coast in April last year, farmers simultaneously pumping water for frost protection caused a sharp drop in the Russian River and some tributaries, stranding and killing a "significant" number of newly hatched salmon "fry."
The fish kills were in Felta Creek in Sonoma County and the Russian River near Hopland in Mendocino County, fisheries officials said. Exact numbers of fish deaths were not available.
The fish deaths last year spawned the creation of a task force that includes federal, state and local water and fish agencies and farmers. The group has been working since June to find solutions to the problem, which has been worsened by the ongoing drought.
"It seems imperative to act now," Steven Edmondson, the agency's Northern California habitat supervisor, wrote in a February letter to the water board.
The letter sent shock waves through the farming community.