Hydrobiologia 505: 199–215, 2003. 199 © 2003 Kluwer Academic Publishers. Printed in the Netherlands. Salt Ecosystems Section A comparison of zooplankton communities in saline lakewater with variable anion composition A.M. Derry1,2,E.E.Prepas3 & P.D.N. Hebert4 1Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada 2Present address: Department of Biology, Queens University, Kingston, Ontario, K7L 3N6, Canada E-mail for correspondence:
[email protected] 3Faculty of Forestry and Forest Environments, Lakehead University, Thunder Bay, Ontario, P7B 5E1, Canada 4Department of Zoology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada Received 7 March 2003; accepted 23 May 2003 Key words: community, ionic composition, saline lakes, zooplankton Abstract Although salinity and aquatic biodiversity are inversely related in lake water, the relationship between types of salts and zooplankton communities is poorly understood. In this study, zooplankton species were related to environmental variables from 12 lakes: three saline lakes with water where the dominant anions were SO4 and −1 CO3, four saline lakes with Cl-dominated water, and five dilute, subsaline (0.5–3 gl total dissolved solids) lakes of variable anion composition. Although this study comprised only 12 lakes, distinct differences in zooplankton communities were observed among the two groups of chemically defined saline lakes. Canonical correspondence analysis identified total alkalinity, sulphate, chloride, calcium, sodium, potassium, and total phosphorus as all contributing to the first two ordination axes (λ1 =0.97andλ2 = 0.62, P<0.05). The rotifer Brachionus plicatilis and the harpactacoid copepod Cletocamptus sp. prevailed lakes with Cl-dominated water. In contrast, the calanoid copepods Leptodiaptomus sicilis and Diaptomus nevadensis were dominant in the SO4/CO3-dominated lake water with elevated potassium (79–128 mg l−1) and total phosphorus concentrations (1322-2915 µgl−1).