Comparative physical and chemical limnology of two Canadian high arctic regions: Alert (Ellesmere Island, NU) and Mould Bay (Prince Patrick Island, NWT)

The physical and chemical limnological characteristics of 65 lakes and ponds from two areas in the Canadian High Arctic were examined to determine differences in regional limnology due to geological and vegetational characteristics, as well as other climate factors. Sites in the Alert region of northern Ellesmere Island had relatively low concentrations of total phosphorus (median TP = 9.1 mug l(-1)), and total N (median = 0.465 mg l(-1)). Dissolved organic carbon (DOC) concentrations were relatively low (median = 2.7 mg l(-1)) reflecting the sparsity of vegetation in the region. Within the Alert dataset, there were pronounced differences in water chemistry between small tundra ponds and larger, deeper lakes. The first axis of a principal components analysis of the Alert dataset reflected conductivity and nutrient gradients (lambda = 0.28), while the second axis (lambda = 0.20) was related to metal concentrations. Mould Bay sites on Prince Patrick Island had relatively high concentrations of TP (mean = 16.5 mug l(-1)), total N (mean = 0.616 mg l(-1)), and DOC (mean = 6.7 mg l(-1)). Mean total N and DOC were at the highest levels yet measured from any similar high arctic limnological survey, while mean TP was the second highest high arctic value yet recorded in our surveys. A principal components analysis of the Mould Bay data indicated that the two dominant gradients in the dataset were conductivity and related variables (k = 0.30) and nutrients (k = 0.19). The differences in water chemistry variables between Mould Bay and all previous high arctic surveys is attributable to the relatively dense vegetation and deep soils present at Mould Bay relative to Alert and other high arctic regions.