Crayfish Threaten Rare Crater Lake Mudpuppies

When Crater Lake National Park enthusiast William Steel stocked the fishless lake with trout in the late 1880s, he unknowingly upset the food chain and endangered the lake’s unique sub-species of salamander called the Mazama Newt.

In 1914, park biologists noticed the trout were languishing from lack of food, so they planted crayfish in the lake, including 5,000 from Odell Lake and 10,000 from the Sprague River. Today they occupy 80 percent of the lakeshore.

By the 1990s, the biologists realized the aggressive crayfish were eating and chasing newts from limited food resources. The eight-inch newts, affectionately known as mudpuppies, had been the lake’s top predators for thousands of years before the crayfish invasion.  The park removed more than 5,500 crayfish from the lake between 2012 and 2014 without any noticeable impact on the declining newt population.

Park aquatic biologist Scott Girdner told the Klamath Falls Herald & News that scientists are stumped on how to reduce the crayfish danger for the Mazama Newt.  He said scientists are asking themselves, “Will newts persist or be driven to extinction?

One thing is clear: it’s tough being low on the food chain.