Development of geomorphic typologies for identifying Lake Sturgeon (Acipenser fulvescens) habitat in the Saskatchewan River System

Abstract

Lake Sturgeon (Acipenser fulvescens) are a large migratory fish species native to the Saskatchewan River system. This species is currently challenged by habitat fragmentation and degradation due to river impoundment. Lake Sturgeon are listed as endangered by the Committee on the Status of Endangered Wildlife in Canada and are being considered for listing under the SARA (Species at Risk Act). Lack of habitat data for the Saskatchewan River system hinders effective management practices for this species and the rivers in which they live. A novel habitat identifi cation method has recently been developed combining techniques from various disciplines. GIS (Geographic Information System) and multivariate derived geomorphic response units (GRU) define reaches along river systems that exhibit similar geomorphic structure and provide a link between the hydrological regime and species habitat preference. Fish movement data collected in ongoing Lake Sturgeon studies in the Saskatchewan River system provide location and migration data allowing for the characterization of known over-wintering sites. Ultimately, by combining GRUs and fish movement data sets we can characterize areas of known use to locate prevously unknown areas. Identification of these links has the potential to greatly increase efficiency of managing this endangered species by allowing a priori selection of sampling sites and prediction of how the effects of anthropogenic changes in river morphology may impact sturgeon habitat.