The fish community of Hamilton Harbour, Lake Ontario: Status, stressors, and remediation over 25 years

Hamilton Harbour is a large (21 km2) protected harbour located at the western end of Lake Ontario that was designated as an Area of Concern in 1985 by the International Joint Commission. As part of the designation, the fish community was deemed “impaired.” One of the long-term goals of the Hamilton Harbour Remedial Action Plan is to rehabilitate the fishery to a state, at least in part, to what it was prior to the degrading effects of industrial and municipal pollution, habitat loss, and invasive species. Since the Area of Concern designation, the nearshore fish community has been monitored regularly via a federal boat electrofishing program (1988–2013) and more recently, by a trap net program (2006–2012). During the study period, the harbour underwent significant physical and biological change which was related to both lake-wide (e.g. Dreissenids) and localized harbour events (e.g. habitat restoration). The fish community was assessed temporally using two indices of ecosystem health, the Great Lakes Inde...