Chinook Salmon may be Barged Around Damsby Kevin McCullen
The News Tribune, April 10, 2010
Juvenile steelhead and spring/summer chinook salmon should be collected and barged around Snake River dams during the critical migration time in May because of projected low water flows, a federal agency has proposed.
The Army Corps of Engineers started spilling water last weekend from its Snake River dams and will start spilling Saturday at the dams on the Columbia River to help the migration of the fish to the Pacific Ocean.
But a mild winter and the resulting lower water supply have prompted federal managers to consider halting spills in May at the Lower Granite, Little Goose and Lower Monumental dams on the Snake River and to barge fish to below Bonneville Dam on the Columbia to aid endangered wild steelhead and spring/summer chinook during their seaward journey.
NOAA Fisheries Service filed the proposal in U.S. District Court in Portland, where Judge James Redden is overseeing operations of the dams while deciding a lawsuit involving the salmon recovery issue.
Wild steelhead and spring, summer and fall chinook are listed under the Endangered Species Act in the Snake River system.
Biologists with NOAA Fisheries based their barging recommendation on scientific studies of runs over a period of years, including a similar low-water year in 2007. That year, fish were barged downstream and also allowed to migrate naturally through water spilling over the dams.
Barging is one method for ensuring fish survival under the salmon recovery document mandated by the Endangered Species Act -- the 2008-2018 Federal Columbia River Power System Biological Opinion.
The NOAA studies found that juvenile salmon and steelhead that were transported in 2007 have returned at higher levels as adults than those that made their way downstream through spilling.
Maintaining spills and barging during low-flow water years "places too great a risk on the wild (Snake River) steelhead and spring/summer Chinook populations as they would likely result in substantially fewer adults returning to the Snake River basin in subsequent years," according to NOAA's proposal.
Water flow on the Snake for the April-July time frame is forecast to be 56 percent of average, according to NOAA hydrological data.
During low water periods, juvenile fish are susceptible to predators and higher water temperatures, said Rock Peters, fish program manager for the Corps' Northwest region.
The spring migration starts in April and peaks in May. Barging juveniles in May to below Bonneville also gives them the benefit of a good food supply in the lower part of the estuary of the Columbia nearer the ocean.
"If they get there too late, they miss the opportunity for good feeding in the estuary and the ocean," Peters said.
Studies also have shown that barging in April puts smolts in the estuary too early to provide as much benefit, he said.
Rep. Doc Hastings, R-Wash., sent a letter to NOAA Fisheries on Thursday supporting the barging plan.
"Moving from spilling water to transporting juvenile fish in a low water year is supported by science," Hastings said in a statement. "It also saves Northwest families and businesses money in these tough economic times by generating clean, low-cost hydropower rather than water bypassing the turbines through spill. Transport would restrict the need for expensive water spills and would also protect the young salmon from predators, low flows and warmer water conditions."
The Northwest Fish Passage Center, which provides technical services to fish agencies and Indian tribes affected by the operation of the Federal Columbia River Power System, disagrees with NOAA's scientific analysis.
In its review, the center said a period of no spills would "adversely impact a significant proportion of the total migration of juvenile salmon and steelhead remaining in-river."
Barging may be detrimental to such species as sockeye salmon, and "what data there are suggests that there is no benefit to transportation for Snake River subyearling chinook," Michele DeHart, center manager, wrote in a memorandum.
NOAA Fisheries asked the Independent Scientific Advisory Board to review its proposal. The board was formed in 1996 by NOAA Fisheries and the Northwest Power and Conservation Council to provide independent scientific advice and recommendations on issues relating to fish and wildlife programs.
The board is scheduled to issue its non-binding report today to NOAA Fisheries. The final decision will be up to the Corps, but Peters said it "absolutely will be following NOAA's recommendations."
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