Oregon biologists poised to rescue Deschutes River fish as flow drops in October near Bend

Oregon biologists poised to rescue Deschutes River fish as flow drops in October near Bend
By The Oregonian

October 7, 2014

A 2013 water draw down killed hundreds of fish stranded in a side channel of the Deschutes River south of Bend.

An operation to rescue and relocate fish on the upper Deschutes River at Lava Island Falls will kick into gear Oct. 20, the Oregon Department of Fish and Wildlife announced Tuesday.

Fishery biologists from ODFW, along with staff and volunteers from several governmental, conservation and fishing organizations, will try to save stranded fish by moving them from shallow, isolated pools near the falls to the Deschute’s main channel.

Redband trout, brown trout, mountain whitefish and sculpin will be captured and relocated to the upstream main channel. ODFW will have several biologists and technicians onsite as well as volunteers during the one or two day operation.

“The extent of the one-mile Lava Island side channel fish rescue and relocation is daunting,” Brett Hodgson, an ODFW fish biologist said in a press release. “We will capture as many fish as we can with nets, seines and electrofishing units, if necessary, but it is impossible to rescue all of them.”

Some of the areas where fish may be stranded are up to a half mile from where they can be safely released back into the Deschutes.

The operation is aimed at avoiding a repeat of the 2013 water draw down that killed hundreds of fish stranded in a side channel of the Deschutes River south of Bend.

This year, captured fish will be placed in five-gallon buckets of water equipped with small battery operated aerators to help provide the fish oxygen until they’re released. The buckets will be hand carried up or down the Deschutes River trail to the point of release by the cadre of volunteers.

“The personal safety of all those involved in the rescue and relocation effort is paramount,” Hodgson said. “Our goal is to save as many fish as possible. However, hauling five-gallons buckets filled with water and fish over rough terrain poses a certain amount of risk for all those involved.”

What may help reduce the numbers of stranded fish is an experimental plan developed by local irrigation districts and the U.S. Bureau of Reclamation. The plan calls for a slower draw down of water levels in the river – over 12 days rather than the usual 2 to 3 days – in hopes more fish may be able to find refuge in the main channel before getting stranded in isolated pools.

“While hopefully this experiment will minimize the fish stranding issue, ODFW stresses the need for a long-term solution to the water management issues on the upper Deschutes River,” Hodgson said. “We view this as a water management issue, not a fish management issue.”

ODFW staff also will collect data on the species, size and number of fish that are rescued.

Of concern for ODFW is that current water management results in much higher summer flows and lower winter flows than were historically present.

Natural flow at the Lava Island site was stable at approximately 1,000 cubic feet per second. Under current water management, flows fluctuate between 2,000 cfs in summer and 300 cfs in winter. This limits the river’s ability to support a healthy trout population. While fish stranded in the side channel are the most visible symptom of low winter flows, the reduced winter flows impacts the trout population in the entire 55-mile reach of the Deschutes River from Wickiup downstream to Bend.

“Until there is a long-term water management strategy that ensures sufficient winter river flows, the fish face more die-offs into the future,” Hodgson said.

Last year, approximately 450 redband and brown trout, and hundreds of whitefish and sculpin, died when falling water levels left them stranded in the natural lava side channel, which normally has water only during higher flows. ODFW staff and volunteers were able to rescue about 750 trout.

This year’s effort will come just as water levels reach minimum levels. Helping ODFW with the rescue and relocation operation will be staff and volunteers from the U.S. Forest Service, U.S. Fish and Wildlife Service and local fishing clubs.

Volunteer efforts are being organized by the U.S. Forest Service, Bend-Fort Rock District office. People who wish to volunteer must register in advance, and be prepared to handle heavy buckets in rocky, difficult terrain.