Evaluating the efficacy of ecological restoration of fish habitat in coastal waters of Lake Ontario

Ecological restoration is a common strategy applied to degraded wetlands and tributaries in large lakes. As resources are typically limited for restoration, it is essential to ensure that such efforts achieve associated goals. Using both discrete and continuous methods, we evaluated the efficacy of ecological restoration efforts on fish habitat within Canada's largest city, Toronto (Cell 2 and Embayment D of Tommy Thompson Park) relative to a control site (Toronto Islands). First, we used a long-term electrofishing dataset (i.e., discrete) to examine catch and community composition relative to restoration status. Catch for northern pike ( Esox lucius) ) remained constant at both restoration sites, and catch of invasive common carp ( Cyprinus carpio) ) decreased at Embayment D, indicating that exclusion barriers may be effective. Restoration was less effective for largemouth bass ( Micro- pterus nigricans) ) as catches remained similar after restoration at Cell 2, but decreased within Embayment D. We also found that relative abundance for coldwater species at both restoration sites decreased post-restoration, with increases in warmwater species at Cell 2 and coolwater species at Embayment D. Next, we used a long-term acoustic telemetry dataset (i.e., continuous sampling) with three focal species: largemouth bass, northern pike, and invasive common carp. Based on telemetry, we found that restoration efficacy was species-specific, with largemouth bass present before and after ecological restoration (particularly in spring, which may be