Fish Diversity and Biomass in Small Subarctic Lakes: Higher Than Expected Relative to Southern Canadian Lakes

Biodiversity in the subarctic region in Canada is projected to experience drastic changes due to increasing human activities (mineral exploration and development) and climate change. Our current knowledge of biodiversity in this region is relatively limited, especially for fish. Because this region is generally thought to have low biodiversity and productivity, it has been assigned relatively low values for their biological resources. In collaboration with the Department of Fisheries and Oceans of Canada, we analyzed species diversity, abundance, and biomass data for fish from 37 small lakes (20 ha – 200 ha) in Northwest Territories, Canada (64ºN 110ºW); for 9 of these lakes, all fish were removed and identified before the lake was destroyed for mining activities. We found that Lake trout (Salvelinus namaycush) was the dominant species in this system. Contrary to the expectation that northern lakes would be poorer in fish diversity and biomass relatively to southern Canadian lakes of similar size (in Ontario), our results indicate relatively similar levels of species richness and biomass across both regions.