TOBERMORY — Over the past 20 years quadrillions of invasive mussels have been sucking the life out of the Great Lakes. They’re trapping nutrients, the basic building blocks of life, on the lake bottom. Without nutrients, organisms of all kinds - from the tiniest plankton to the largest fish - are vanishing. In Lakes Huron, Michigan, and Ontario, vast offshore areas have become “biological deserts,” heralding one of the biggest changes to the Earth’s freshwaters in 10,000 years.