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Fish carcass tossing helps track food chain nutrients

Black bear
Grizzly bears and black bears feed on naturally spawning salmon and distribute nutrients into the forest. Photo by U.S. Fish & Wildlife Service.

By Bob Hoffmann, College of Agricultural, Human, and Natural Resource Sciences

A slender, dark-haired woman in her forties shoulders a backpack loaded with dead fish as she hikes a long, rocky trail to a mountain stream in southern Idaho. Arriving on the bank, she drops the pack and starts winging fish carcasses into the water.

This is science. And this is Laura Felicetti, a research scientist in the lab of Charles Robbins, professor in the School of the Environment and School of Biological Sciences at Washington State University. Felicetti is a member of a team that’s trying to quantify the success of nutrient replacement in an area where dams have stopped salmon and steelhead from migrating.

Nutrient-poor soil

Soils in Idaho’s Boise-Payette-Weiser sub-basin are nutrient poor, according to Katy Kavanagh, a University of Idaho forest ecology professor and a collaborator on the project. One reason is that natural processes in this ecosystem poorly incorporate atmospheric nitrogen into the soil in a form that is usable to plants. Also, the region’s dry summers and cold winters are not favorable to decomposition, so dead trees are slow to decay and make their nutrients available to other plants.  Continue story →