The Billings Gazette –
This is the first in a series of articles looking at Idaho’s salmon and steelhead runs and the perils they face. Consider this first offering an introduction course, Salmon and Steelhead 101.
The Snake River has four species of Pacific anadromous fish — spring and summer chinook, fall chinook, summer steelhead and sockeye.
Wild runs and some hatchery runs of all four are protected by the Endangered Species Act, with endangered sockeye having the highest level of protection. The fish were listed between 1991 and 1997, with steelhead the last to be protected. Idaho and northeast Oregon also have a run of coho salmon. This run was reintroduced to the state by the Nez Perce Tribe after being declared functionally extinct in 1986. Coho aren’t protected under the Endangered Species Act.
Spring and summer chinook, which are grouped into a single category, are the first to return in the calendar year. As their name denotes, they return from the ocean as adults in the spring, usually in April, May and June. They spawn in late summer in tributary streams or the upper reaches of main rivers such as the Middle Fork Salmon River and main Salmon River, once those rivers become smaller and behave more like streams.