By Gregg Losinski, Upper Snake River Valley Regional Conservation Educator
When you mix 200 volts of electricity with water you're setting the stage for some shocking results.
That is just what Fisheries biologists with the Idaho Department of Fish and Game found during their recent population surveys on the South Fork of the Snake River. Each year, researchers use electro-fishing equipment to assess populations near Conant Valley. This is the year they've been waiting for to learn how well the cutthroat population is responding to efforts to save the famed fishery.
In 2004, the Fish and Game changed fishing regulations on the river to allow unlimited harvest of rainbow trout, while changing cutthroat to all catch-and-release. In addition, the department worked with the Bureau of Reclamation to modify flows to benefit cutthroat trout. According to Jim Fredericks, Regional Fishery Manager, the October 2005 surveys are the first time they'd be able to gauge the effectiveness of the modified flows from Palisades Dam.
So far, the results are encouraging. The cutthroat population was up about 27 percent from last year, primarily a result of a good year-class of fish produced in 2004. After several successive years of poor recruitment, the good production was a welcome sight. "This is extremely important information" Fredericks said. "The Bureau of Reclamation has worked with water users and the fisheries community to implement these experimental flows, and now it looks like those efforts are paying off."
While cutthroat trout numbers were on the rise, Fish and Game was equally encouraged to see a decline in the rainbow population. There have now been two successive years in which the surveys have shown a decrease in the rainbow population. In fact, the population is down an estimated 55 percent since October 2003 from nearly 1,500 fish per mile to 670 fish per mile, which is the lowest it has been in 10 years.