Invasive mussels hit Great Lakes fisheries

Posted on June 26, 2010

In the Great Lakes of North America, the spread of introduced zebra mussels and quagga mussels (Dreissena species) since the late 1980s has led to major changes in the populations of bottom-dwelling animals.  Dreissena compete for food with native species, and their abundant shells and waste products significantly modify the lake sediments.  Populations of several major invertebrate groups declined by up to 75% between 2000 and 2003.  These invertebrates included species of Diporeia (scuds, or amphipods).  Because Diporeia are the main preferred food of the lake whitefish, their demise has caused whitefish to switch to less profitable prey.  At the same time there have been strong declines in whitefish growth and abundance, with serious implications for commercial fisheries of theGreat Lakes.

Reference:  Nalepa, T.F., Pothoven, S.A. & Fanslow, D.L.  2009.  Recent changes in benthic macroinvertebrate populations in Lake Huron and impact on the diet of lake whitefish (Coregonus clupeaformis).  Aquatic Ecosystem Health & Management, 12(1), 2–10.