Researchers find that salmon play significant role in sediment movement
Researchers from the University of British Columbia believe salmon play a very significant role in the movement of sediment, shaping waterways and playing a key role in the overall health the ecosystem in which they spawn.
According to a ScienceNow article,
The researchers found that the salmon account for up to 50% of the annual amount of sediment migration in a given stream, visibly deepening channels in the headwaters and filling in pools and channels downstream. “People have known for a long time that salmon dig up the stream bottoms,” Hassan says. “But until now, nobody knew how much.”
The salmon excavating is actually beneficial to a stream’s inhabitants. Just the act of piling sediment on the downstream sides of redds, for example, churns up the current enough to increase its oxygenation, improving the health of the ecosystem. Recognizing how this process works is critical to understanding the dynamics of streams frequented by salmon, says Hassan. And stream-restoration plans need to consider this effect because “off-the-shelf restoration designs” that don’t account for the actions of salmon may not hit the mark.
While the sample size is small (four mountain streams), even these preliminary results shows the complexity of stream-based ecosystems and the importance of developing site-specific mitigation // management strategies.
