More Beaver Activity, More Coho Salmon
Anecdotal reports from the public have revealed that beaver activity has grown in northern Alaska and looks to have an impact on salmon.
Steve Ivanoff is a lifelong fisherman and resident in Unalakleet. He says the increase in activity he thinks is due to both the warming climate and a decrease in beaver hunting and trapping. The meat was often used to feed sled dogs – now mostly replaced by snowmachines and Ivanoff says North Face and Mountain Hardwear has replaced some of the prevalence of the traditional beaver hat.
With the increased activity, there are more dams, which bring an increase in still ponds. Biologists and fishermen believe that the increase in the amount of still water has benefited one species of salmon – the coho – or silver salmon. There hasn’t been a formal study on the correlation, but observation from biologists and subsistence fishermen make a strong argument.
Fisheries biologist Scott Kent says dammed water is a great place for young salmon growing in fresh water. He says when coho fry hatch in the spring they swim upstream:
Kent says the beaver activity creates what’s called habitat permanence and thermal permanence.
When there’s a lot of freeze down, Kent says it compresses the juvenile salmon to small areas where food resources are finite, creating competition for food. This would not be a problem for salmon that winter in the deep ponds.
But the increased beaver activity isn’t beneficial for all salmon species. For example, the department of fish and game has seen a chum run diminish east of Elim.
The reason chum and pinks do not adapt well to beaver habitat is because they do not jump over obstacles like the coho.
Coho salmon – after hatching – typically spend two years in fresh water before heading out to sea – leaving as three to six inch fish and coming back between four and thirteen pounds.