Science

Zebra mussels are an invasive, fingernail-sized mollusk that is native to fresh waters in Eurasia. Their name comes from the dark, zig-zagged stripes on each shell. Zebra mussels probably arrived in the Great Lakes in the 1980s via ballast water that was discharged by large ships from Europe. They have spread rapidly throughout the Great Lakes region and into the large rivers of the eastern...

The USGS documents the zebra mussel's geographic distribution and studies its behavior and biology. The resulting information is critical in helping to develop strategies aimed at containing and controlling the mussel's spread. Meanwhile, catching and transporting zebra mussels for use as bait, food, and aquarium pets is highly discouraged. We also encourage good boat hygiene: Wash your boat off...

Tamarisk is an invasive shrub or small tree that is found across the American West. Also known as saltcedar, tamarisk favors sites that are inhospitable to native streamside plants because of high salinity, low water availability, and altered streamflow regimes created by dams. Researchers debate the extent of tamarisk’s negative impacts, but this invasive species can and does alter habitat...