Mapping the Potential Spread of the Zebra Mussel (Dreissena polymorpha) in Ontario

Abstract

The European zebra mussel (Dreissena polymorpha) is now firmly established in the lower Great Lakes and in isolated locations in the upper Great Lakes. Dispersal is aided by high fecundity, a planktonic larval stage, and ability of the mussel to be transported via shipping and recreational boating. Almost all waterbodies in Ontario which are downstream of established colonies or which can be reached through boating are vulnerable to invasion. However, there are ecological requirements (derived from European literature) which limit successful zebra mussel reproduction. Using data from over 6000 inland lakes in the province, we have prepared maps which show the distribution of pH, calcium, and major access routes and which indicate our estimated potential for success or failure of zebra mussel colonization. The utility of the maps is dependent on the validity of the ecological requirements for successful development of zebra mussel larvae, which were developed in Europe. There is a need to test the chemical requirements of the zebra mussel in North American waters.