Since January, the Tahoe Resource Conservation District (TRCD) and Tahoe Regional Planning Agency (TRPA) have inspected more than 5,600 vessels. Of those thousands of vessels, 59 have been flagged for carrying invasive species,

The results were unexpected: They found adult walleye in lakes infested with zebra mussels had 72% higher mercury concentrations than in lakes without the invaders. In yellow perch — a common prey for walleye — the mercury concentrations were 157% higher.

A study found that invasive zebra mussels significantly alter aquatic ecosystems, and are associated with elevated mercury concentrations in fish. Mercury, a potent neurotoxin, poses a serious threat to both aquatic life and human health.

Zebra mussels are significantly altering the ecosystems of Minnesota lakes, according to a study that ties the invasive species to higher mercury levels in fish.