Ich Infections Plague Klamath River Salmon
SOMES BAR, CALIFORNIA –As the worst drought in California history persists, Klamath River conditions continue to deteriorate. Last week Yurok biologists detected ich infections in the lower Klamath. This week Karuk biologists detected ich infections in the mid Klamath. So far no mortalities due to the infection have been observed, but monitoring will continue. Many may recall that in September 2002, low flows and warm temperatures led to an outbreak of ich that culminated in the largest adult salmon kill in US History on the Klamath River when nearly 70,000 fish died.
Ich is a common name for the non-native parasite Ichthyophthirius multifiliis and the disease that it causes. The parasite is capable of killing large numbers of fish in a short period of time when fish densities are high as is the case in the lower Klamath River when fall Chinook enter the river in large numbers.
In response to the disease outbreak, the Bureau of Reclamation began increasing releases of water Tuesday from Trinity Reservoir. This will provide a large increase in flows for the lower Klamath River that will dilute disease causing parasites looking for hosts and reduce high concentrations of fish, all an effort to disrupt the disease life cycle.
“We don’t have the water storage on the Mainstem Klamath that allows for such actions,” explains Craig Tucker, for the Karuk Tribe. “The PacifiCorp reservoirs store little water and the water they do store is warm and riddled with toxic algae.” The limited water storage on the main-stem Klamath is from Upper Klamath Lake which is also running low on water as the Bureau tries to comply with ESA regulations pertaining to suckers in the Lake and coho salmon in the river below.
Water management flexibility is much more limited on the main-stem Klamath than it is on the Trinity. Trinity Reservoir can hold over 2.4 million acre feet of water, It currently has over 660,000 acre feet in it. By comparison, Upper Klamath Lake is a natural lake system and holds less than 500,000 acre feet. The PacifiCorp dam is much less than that as they were designed to be run of river facilities, that is to say that they pass as much water as comes in for most of the year. They can actively store less than 12,000 acre feet of water.
It may seem that little can be done to improve conditions for fish in the Klamath upstream of the Trinity confluence, that’s not true according to Tucker, “as these fish make their way to the tributaries they want to spawn in, we need all water users to reduce or even stop diverting or pumping groundwater as soon as possible.”
Legal and illegal diversions throughout the Klamath Basin continue to de-water tributaries making it difficult or impossible for Chinook to reach spawning grounds.
According to Karuk Tribal Chairman Russell ‘Buster’ Attebery, “We believe that state and federal agencies can do more to regulate legal diversions and shut down illegal diversions according to existing laws and statutes. There are plenty of laws aimed at protecting fish on the books and they need to be enforced.”
Finally, there are the Klamath Restoration Agreements which await congressional approval. “If Congress would enact these Agreements they would lead to dam removal, improved irrigation efficiency, better river flows, and habitat restoration. Together these measures would go a long way towards avoiding disease outbreaks in the future,” says Attebery.