Spatial Ecology of Fish within Toronto Harbour in Response to Habitat Enhancement

Throughout the Laurentian Great Lakes, coastal habitats have been heavily impacted by anthropogenic development resulting in a loss of coastal habitat. In 1987, the Toronto Harbour was designated as an area of concern (AOC) due to habitat loss and degraded water quality. Various restoration, naturalization, and habitat creation projects have been put in place in hopes of delisting this AOC by 2020. One specific project includes the naturalization of an urban slip along the Toronto shoreline. To assess the effectiveness of this project, habitat selection and residency of eight fish species (Largemouth bass, Northern pike, Common carp, Walleye, Yellow perch, Brown bullhead, Bowfin, White sucker) were compared among the enhanced slip and three other slips not subject to enhancement (area of the slips ranged between 6,000 m² and 12,000 m²). Fish were implanted intracoelomically with acoustic transmitters and monitored for a year using a Vemco positioning system (VPS). We predicted that the enhanced habitat would be selected more often by fish and yield higher residency times compared to the other non-enhanced sites. It is important to assess the effectiveness of such restoration efforts to improve the design of future habitat enhancement projects and maximize the efficiency of delisting AOCs.