An upcoming issue of Geophysical Research Letters has very interesting observations about Salmon. Led by geomorphologist Marwan Hassan of the University of British Columbia in Vancouver,Canada, the research opens up new info about various facets of Salmon migration unknown to us till now. The researchers found that the salmon account for up to 50% of the annual amount of sediment migration in a given stream. People have known for a long time that salmon dig up the stream bottoms. But it is the first time that details about how they do it are coming out. Sediment traps were used to track the movement of preplaced magnetized particles to study the effect of salmon digging up in four mountain streams in British Columbia. Oxygenation of the river is improved by this activity of Salmon. Multiplied by millions of salmon, and repeated year after year the shape of streambeds and the health of stream ecosystems are directly affected. The researchers feel that the fish could be shaping larger-scale valley features and even influencing landscape evolution.
The inputs for this post have come from ScienceNOW Daily News.
2 comments:
When I worked for Idaho Fish & Game in 2000, they were just beginning to look at the impact of salmon in catch basins where they return to their natal streams as well. The influx of marine-derived nutrients seems to have enormous impact on sterile, high-mountain environments where their bodies are eaten and later defecated miles from the stream, dragged onto shore to rot and decomposing within the stream as a nutrient source for the plankton and zooplankton on which their own young may feed. I think we'll find more and more as we study Salmonids' link to their environment that they are more interconnected than we could ever have imagined. We did the the world no small disservice by making the great Columbia the most hydroelectrically harnessed river in the world!
Thanks for the info
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