By Eric Sorensen, WSU News

fish PULLMAN, Wash. – It turns out that sex can move mountains.

A Washington State University researcher has found that the mating habits of salmon can alter the profile of stream beds, affecting the evolution of an entire watershed. His study is one of the first to quantitatively show that salmon can influence the shape of the land.

Alex Fremier, lead author of the study and associate professor in the WSU School of the Environment, said female salmon “fluff” soil and gravel on a river bottom as they prepare their nests, or redds. The stream gravel is then more easily removed by flooding, which opens the underlying bedrock to erosion.

“The salmon aren’t just moving sediment,” said Fremier. “They’re changing the character of the stream bed, so when there are floods, the gravel is more mobile.” More…..