Crustacean Plankton Communities of 340 Lakes and Ponds in and near the National Parks of the Canadian Rocky Mountains

The crustacean plankton communities of 340 lakes and ponds in southern Alberta and southeastern British Columbia were examined. The waters are situated between 660 m and 2455 m in elevation, have areas from < 0.1 to 3940 hectares, and range from 0.5 m to 136 m in depth. They represent a wide range of salinities, from 2 ppm to 29,800 ppm. The communities were grouped into seven main types on the basis of the copepod species present. Of the 97 crustacean species present, 32 were copepods, 50 were cladocerans, and 9 were anostracans. The three most common species accounted for over 25% of the total species occurrences. Only two species were present in more than half the total lakes and ponds. A few species seem to be restricted to highly saline waters, and a few to low salinities, but most inhabited a wide range of aquatic environments. The most frequently occurring and abundant species tolerate a wide range of conditions. These species are also characterized by up to a fivefold variation in generation time. Certain species having restricted distribution patterns appear to be limited by both the chemistry of the water and the heat content. Aspects of species distribution, ecology, and interspecific relationships are discussed.