Impact of Geese on the Limnology of Lakes and Ponds from Bylot Island (Nunavut, Canada)

Arctic freshwater ecosystems are important habitats for northern wildlife. Arctic climate impact studies suggest that global change could result in major modifications and perturbations of lakes, ponds and wildlife. Most studies focus either on freshwater ecosystems or on animal populations, but few have investigated the links that exist between them. Animal populations have the potential to alter the nutrient inputs in lakes and ponds via faeces. The present study is the first to reveal the impact of an expanding Greater Snow Goose (Chen caerulescens atlantica) population on the limnology of arctic lakes and ponds. A survey of 27 freshwater ecosystems was performed on Bylot Island (Nunavut, Canada) in order to identify patterns in limnological conditions. Using a multivariate statistical approach, our study shows that the presence of birds in the catchment of lakes and ponds has an impact on their nutrient status. Concentrations of major ions that were related to the distance from the sea were the main environmental variable explaining the limnological differences observed among lakes and ponds. Nutrient variables that were mostly related to the presence of Snow Geese played a secondary but significant role. N and P concentrations were different among impacted and non-impacted sites, underlining the impact of animal populations on northern freshwater ecosystems.