Just a little bit of old knowledge. Some years ago, these same minded people, got the bright idea to help salmon smolt make it out of the Yakima river drainage. So they got the people who operate the dams that hold back water in the various resovoirs.
The result was the water came boiling down the river and was oxygenized and the fish died. Behind several of the dams on the Columbia the waters were teeming with dead salmon.