Changes in Freshwater Fish Community Structure and Function from Resource Extraction

Canada is a country with a wealth of natural resources including the second largest forestry producer, the third largest oil reserves, and is the fourth largest natural gas producer, globally. Much of this production stems from the province of Alberta, home to 98% of Canada’s oil reserve and a booming forest and natural gas sector. Extraction of these resources is likely to alter aquatic systems due to in-stream habitat alterations and modifications. Here we assess changes in freshwater fish community structure and function during the past 40 years in western Alberta, an area undergoing dramatic landscape level changes. We use 14 Landsat images to retrospectively relate landscape changes to freshwater fish community structure and function over a 35 year period (1973-2008). Freshwater fish communities were compared using rarefaction techniques using traditional species diversity metrics, as well as measures of functional diversity such as Rao’s quatradic entropy, FD, and functional eveness. The rate of change in landscape level disturbance in western Alberta increased over ten-fold from 0.04% in the 1980’s to 0.48% in the 2000’s. We show that these changes not only effected landscape level processes, but fragmented stream habitats and caused drastic changes in fish community structure and function.