Understanding Habitat and Connectivity in Lake Simcoe Tributaries to Protect Brook Trout

Session: 56. - Science for a Healthy Lake Simcoe

Cindy Chu, Ontario Ministry of Natural Resources and Forestry, [email protected]
Nicholas Jones, Trent University, OMNRF, [email protected]
Simon Fung, Fisheries and Oceans Canada, [email protected]
Mike Thorn, Ontario Ministry of Natural Resources and Forestry, [email protected]
Richard Di Rocco, Fisheries and Oceans Canada, [email protected]

Abstract

Tributary habitats in the Lake Simcoe watershed have been degraded by in-stream obstructions (dams and barriers), removal of riparian vegetation, watershed land use change, and stormwater runoff. In recognition of these effects, fish community objectives for the watershed include stipulations for the maintenance of remaining Brook Trout populations, protection of coldwater tributary habitat, and where feasible, restoration of historic coldwater tributary habitats. We present research that has been undertaken to model in-stream thermal habitat, Brook Trout distributions, and quantify the effects of stream fragmentation (dam, culverts, and weirs) on Brook Trout habitat connectivity. Using climate scenarios, it was estimated that coldwater habitats have declined 27% since the 1950s whereas hindcasting of landscape conditions suggested that Brook trout distributions may have declined by as much as 47%. A dendritic connectivity index was developed for streams within the watershed to prioritize barriers for removal based on the increase in connectivity and habitat quality when mitigated. These findings are being used by the Ontario Ministry of Natural Resources and Forestry, and the Lake Simcoe Conservation Authority to improve monitoring and management of Brook Trout habitat and populations in the Lake Simcoe watershed.

1. Keyword
watersheds

2. Keyword
habitats

3. Keyword
monitoring

4. Additional Keyword
Brook Trout

5. Additional Keyword
connectivity