PROJECTED DISTRIBUTION OF THE ZEBRA MUSSEL, DREISSENA-POLYMORPHA, IN NORTH-AMERICA

An analysis of the European distribution of the zebra mussel, Dreissena polymorpha, shows that the species probably will spread over much of North America. Only softwater districts and the extreme northern and southern parts of the continent are unlikely to be colonized. Within this range, D. polymorpha is most likely to be found in large, hardwater lakes and in running waters more than 30 m wide. Populations of D. polymorpha probably will spread over a larger part of the lake bottom in shallow, warm lakes than in deep, cold lakes. I could not make any predictions about the expected population densities of D. polymorpha in either lakes or streams.