Thirty Year Update – Muskellunge Nursery Habitat in Southern Georgian Bay, Lake Huron, Canada: Current Stressors and Current Needs

The muskellunge fishery of Georgian Bay, Lake Huron, is a world-class trophy fishery of Ontario. Unfortunately, significant increases in shoreline modification in southeastern Georgian Bay, as well as sustained low water levels since 1999, has substantially altered coastal wetland nursery habitat. We examined the impacts of sustained low water levels and shoreline modifications on the current suitability of historic muskellunge nursery habitat in this region. Originally identified in 1981, nursery sites were resampled with the same methodology in 2012.  Young-of-the-year (YOY) muskellunge were no longer present at the historic sites or in surrounding area.  Sustained low water levels, increased shoreline modifications and Georgian Bay’s unique geomorphology appeared to be contributing factors in altering the habitat structure of these sites, rendering them unsuitable as nursery habitat for musky.  The precise mechanisms limiting survival to the YOY stage are unknown since spawning adults were still observed in the area in 2012. If southeastern Georgian Bay’s muskellunge population is to remain self-sustaining, a complementary management strategy specifically developed for Georgian Bay is required.  This should identify and ultimately protect suitable muskellunge breeding habitat by accounting for the unique geomorphology and current physical stressors affecting Georgian Bay.