Native Arctic grayling living in Upper Red Rock Lake in southwest Montana have seen their numbers nosedive over the past four years, despite an effort to remove what was thought to be competing cutthroat trout from the same waters.
Between 2014 and 2017 the spawning population of grayling in the waters of the Centennial Valley fell from about 2,000 spawning-age fish to 240, despite the removal of almost 90 percent of the hybridized Yellowstone cutthroat trout living in the same streams and lake.
LINK (via: The Billings Gazette)
