Steelhead in Idaho....... and the PNW

Here is a link to a very good article that discusses steelhead survival in Idaho, the Pacific Ocean, and what it means for the future.

Enjoy.

https://idfg.idaho.gov/blog/2017/08/why-are-idahos-steelhead-runs-so-low

A colleague from AK has been looking at the problems up there, which are growing. One thing he is seeing is that adult salmon are diving on their trek from the ocean to the river mouth. He thinks that it is diet related. There is enough nutrition in the food to grow the fish and maintain them in cold/cool water. When they get into warmer water, metabolism goes up and they need more calories just to survive. These calories are lacking.

Using made-up numbers, but serve as an example, lets say that an anchovy has 100 cals per fish and a herring 120 for the same sized fish. The fish can only eat so many because of stomach capacity. If it fills up on anchovy it gets less total calories than if it fills up on herring. The fish "looks" healthy and the stomach is full. It just isn't getting the quality it needs.

I think what is going on in the Pacific is a major ecological shift brought by climate change and fisheries on all species out there. We are creating a different ecosystem yet expecting the original species, who evolved under one set of conditions, to survive another. Perhaps we have traded salmon for Humboldt Squid.

Great write-up. Thanks for posting it.