Progress made in Yellowstone lake trout battle

Ten years after netting operations began, fisheries biologists are finally reaching kill levels necessary to effectively suppress Yellowstone Lake’s lake trout population.

The netting, which is expected to remove 300,000 fish this year, is an integral part of the effort to restore populations of native cutthroat trout. About 500,000 catchable-sized lake trout, invasive and illegally introduced in the early 1990s, are believed to swarm the waters of the 139-square-mile high-elevation lake. Boats netted and killed around 224,000 fish in 2011. But the total kill in the entire decade before was just 500,000.

Because they run upriver and make themselves available to predators, cutthroat were once an important food source for grizzly bears, bald eagles, ospreys and river otters. Lake trout, conversely, spawn in the lakes and oftentimes in deep water — they’ve been documented at 100 feet down.