Spatial ecology of a reintroduced fish (Sander vitreus) in an Area of Concern, Hamilton Harbour, Lake Ontario

Session: 11. - Acoustic Telemetry Applications in the Great Lakes

Jill Brooks, Fish Ecology and Conservation Physiology (Carleton University), [email protected]
Jon Midwood, Department of Fisheries and Oceans, [email protected]
Christine Boston, Fisheries and Oceans Canada, [email protected]
Mathew Wells, University of Toronto Scarborough, [email protected]
Elodie Ledee, Fish Ecology and Conservation Physiology Lab, [email protected]
Susan Doka, GLLFAS, Fisheries & Oceans Canada, [email protected]
Jim Hoyle, ON Ministry of Natural Resources, [email protected]
Lee Gutowsky, Ontario Ministry of Natural Resources and Forestry, [email protected]
Patricia Semcesen, University of Toronto, [email protected]
Steven Cooke, FECPL, Carleton University, [email protected]

Abstract

Hamilton Harbour is an urbanized area at the western end of Lake Ontario and not unlike other coastal embayments in the Laurentian Great Lakes, it has undergone various forms of rehabilitation. To restore the fish community in Hamilton Harbour, several attempts have been made to increase the proportion of apex piscivores by reintroducing native walleye (Sander vitreus). Yet, the effectiveness of these reintroduction efforts remains unclear. The objectives of this study were to determine the residency and seasonal space use within the harbour, with a focus on the spring spawning period. Tagging data revealed that walleye spent most of their time within the harbour and did not migrate into Lake Ontario during the spawning period.  Home range size and position within the harbour varied seasonally, with a significant reduction in home range size during the summer. Monitoring of the dissolved oxygen within the harbour has shown cyclic upwelling of hypoxic waters in summer due to daily seiche events, and, using fish depth data, preliminary results are suggesting these events are reducing the available fish habitat. This information will be important to both fisheries managers and habitat restoration practitioners as efforts continue to re-establish walleye populations and further rehabilitate the harbour.

1. Keyword
acoustics

2. Keyword
walleye

3. Keyword
water quality

4. Additional Keyword
hypoxia

5. Additional Keyword
rehabilitation