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Officials to resume fish growth effort at Dworshak

Published on May 9, 2012 3:01AM

Last changed on May 9, 2012 8:09AM

LEWISTON, Idaho (AP) -- The U.S. Army Corps of Engineers is preparing to restart a project that calls for adding liquid fertilizer to the Dworshak Reservoir to balance nutrient levels and hopefully spur growth of kokanee salmon.

The agency released an environmental impact statement Monday that concludes the addition of liquid fertilizer would not have a significant impact on the 55-mile long reservoir in north central Idaho.

"We are trying to get our guys going this week for an application," Paul Pence, Dworshak Dam and Reservoir natural resource manager for the corps, told the Lewiston Tribune (http://bit.ly/IS3bDn ).

In 2007, the corps and Idaho Department of Fish and Game started adding fertilizer to the reservoir as part of a five-year pilot project. The goal was to balance nitrogen and phosphorus levels and boost growth at the bottom of the lake's food chain.

They hoped the program would improve the health of the aquatic ecosystem and the positive effects would ripple up the food chain and lead to bigger, fatter kokanee.

The project began to produce incrementally positive results, but it also spawned a controversy over what some critics said was an unintended consequence -- blooms of undesired blue-green algae.

Some complained the algae was causing swimmers rash and affecting a downstream fish hatchery. Corps and fish and game officials said the fertilizer actually helped to suppress blue-green algae, and U.S. Fish and Wildlife Service officials said problems at Dworshak National Fish Hatchery were unrelated to the program.

Ron Hanes, who lives in Orofino and is a critic of the project, filed a 60-day notice of intent to sue, claiming the agencies failed to secure the proper permits prior to starting the project. In the fall of 2010, more than three years into the project and before a formal lawsuit was filed, the Environmental Protection Agency said a national pollution discharge elimination system permit was needed to add fertilizer to the water.

Corps officials stopped the project and applied for the permit. Last year the EPA issued the permit and also determined the fertilizer was not responsible for the blue-green algae blooms or problems at the hatchery.

Corps officials determined an environmental analysis was needed before the project could resume. That process was completed Monday when the corps determined the project will not harm the environment.

Pence said fertilizing will continue for another five years.

"We have 3 1/2 years of data and things appeared to be going in the right direction, but it wasn't concrete enough so we are looking at another five years of data to analyze and then will decide if it's worth it," Pence said.

Joe DuPont, regional fisheries manager for the Idaho Department of Fish and Game in Lewiston, said there is some indication that years with high spring floodwater, such as 2011, might push nutrients out of the reservoir. If true, that could raise some long-term questions about the project.

"That is one of the big questions I have, how do big flow events influence the effectiveness of the project? If you have to reset every four or five years and it takes three years to get back to where you see a benefit, is it worth it?" he said. "Those are some of the things we are going to learn."


Information from: Lewiston Tribune, http://www.lmtribune.com

Copyright 2012 The AP.


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