- The Flathead Lake, about 100 miles north of Missoula, Montana, is one of the cleanest lakes in the world—free from toxins, crystal clear and home to a thriving ecosystem.
- The trouble is, the lake is home to invaders that are taking over the great Glacier National Park region.
- Little Shrimp, Big Problem
It all began thirty years ago with the unassuming Mysis relecta, also known as the possum shrimp, a thumbnail-size species of shrimp that was introduced to the lake after a group of scientists showed that adding the shrimp could feed local fish, making them big and strong. But those introducing the shrimp to the world’s 79th largest lake didn’t have long-term data on what these shrimp could do to such a large, complex ecosystem. There were unintended consequences.
2.Ongoing Invasive Threats
Flathead Lake, like many western lakes, is threatened by the creep of zebra or quagga mussels westward from the many lakes East of the Mississippi that these species plague. The mussel is notorious for clogging hydroelectric pipes, boats and even covering local bottom dwellers with phenomenal growth (a female zebra mussel can lay up to 1 million eggs in one season).
Montana is investing in warding off this future threat with cleaning stations and a public relations campaign that the state hopes will educate out-of-staters who can bring the species to untouched lakes when trailering their boats.
3.The Fleas That Once Thrived
The possum shrimp instead ate vast populations of Cladoceran, the ubiquitous water flea that thrive in the lake (shown here in a jar). From there, the ecosystem began a gradual sea change. With the water flea population decimated, smaller organisms like Rotifers took over, doing damage to the two native species that were meant to benefit most from the shrimp, the Westslope Cutthroat Trout and the Bull Trout.