Yellowstone Lake is the largest freshwater lake sitting above 7,000 feet in North America. Because of its deep and cold waters, invasive lake trout have thrived there. They did, after all, evolve in the Great Lakes.
But despite the advantages that the lake’s conditions have afforded the invasive fishes, and the numbers they’ve been able to achieve there, biologists appear to be winning the war against the invasives’ spread. This is thanks to netting boats that operate all day in the summertime, working to capture the lake trout and remove them for good.
Those efforts removed about 315,500 lake trout from Yellowstone Lake in 2015, beating previous years’ totals handily. The use of gill nets to capture the trout, by contrast, has not yielded numbers nearly as good.
Officials at Yellowstone National Park say they’ve killed more than 1 million lake trout since 1994. Half of those were removed from the lake between 2012 and 2014.