Development of a diatom-based specific conductivity model for the glacio-isostatic lakes of Truelove Lowland: implications for paleoconductivity and paleoenvironmental reconstructions in Devon Island lakes, NWT, Canada

Diatoms are identified and enumerated from the surface sediments of 100 lak es of Truelove Lowland, Devon Island, N.W.T., Canada. These lakes range fro m large oligotrophic lakes, to small tundra ponds, to coastal marine lagoon s which are diverse in terms of ionic concentration and composition. The re lationship between diatoms and 15 limnological variables is examined using Canonical Correspondence Analysis (CCA). Specific conductivity is identifie d as the most important variable influencing the distribution of diatoms in the Truelove lakes. A Weighted Averaging (WA) calibration model is develop ed to predict diatom-inferred specific conductivity. The reliability of the model is tested by evaluating the correlation between observed and diatom- inferred values and determining the error of prediction by bootstrapping. T he applicability of the predictive conductivity equation is demonstrated by reconstructing the paleoconductivity history of Fish Lake.