Cladocera and Anostraca from the Interior Plateau of British Columbia, Canada, as paleolimnological indicators of salinity and lake level

Cladoceran and anostracan species assemblages were identified from the surf ace sediments of 33 closed-basin lakes from the southern Interior Plateau o f B.C. in order to explore their effectiveness as quantitative indicators o f lakewater salinity and ionic composition. These lakes were chosen to maxi mize the range of lakewater salinity concentrations (freshwater through hyp ersaline) as well as brine composition (sulphate and carbonate dominated sy stems). The distribution of the anostracans and cladocerans were strongly c orrelated with lakewater salinity, ionic composition and lake depth. Based on these strong relationships significant predictive models were developed, using weighted-averaging techniques, to infer lakewater salinity based on the species composition of anostracans and cladocerans in surface sediments . Furthermore, models were developed to infer lake depth that are superior to previously used techniques based on the ratio of planktonic/littoral Cla docera. Given that the species composition of anostracans and cladocerans c an be used to infer changes in salinity and lake level, and that their rema ins can be identified from sedimentary profiles, there is considerable pote ntial in using their assemblages as paleolimnological indicators of past cl imatic conditions.