Identifying and mapping essential habitat for fish and freshwater turtles in coastal wetlands of Georgian Bay

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Great Lakes coastal marshes support a large number of aquatic and semi-aquatic species that use them for breeding, feeding and overwintering. In eastern Georgian Bay, Lake Huron, where many coastal marshes are still relatively free from human disturbance, the integrity of coastal wetlands has been threatened by an unprecedented period of sustained low water levels for over a decade. Recently, developmental pressure on these coastal wetlands has also increased because of rising demand for water-front property for seasonal and year-round residences. It is clear that development pressure is too strong to prevent alteration of at least some wetlands on public and private lands. A more effective conservation strategy is to identify and protect essential core habitat and connecting corridors, leaving non-essential wetland habitat available for compatible development. Such a system of habitat ranking is more likely to be embraced by politicians and business interests. My long-term goal is to conduct research to enhance the ability of agencies and conservation groups to identify, classify and map the essential wetland habitat along the Georgian Bay coastline. Since habitat is species-specific, I will focus my efforts on two umbrella species, the muskellunge and the Blanding's turtle, both of which are charismatic; protection for them will ensure protection for the less charismatic wetland-dependant species. For the muskellunge, a top predator and largest freshwater sport fish in Canada, both spawning and nursery habitats are found exclusively in coastal marshes. By comparison, both wetland habitats and travel corridors connecting these must be protected to ensure the survival of the Blanding's turtle, which is a semi-aquatic species requiring both upland and coastal wetland habitat for breeding and feeding, as well as sandy beaches for nesting. My first objective is to use existing data from our lab to develop habitat suitability models (HSM) for both species. These models are maps that represent the best chance of finding the target species given the information we have on how species use their habitat for spawning, feeding and overwintering. The HSM for the Blanding's turtles will be specific to islands in the archipelago, whereas that for the muskellunge will apply to both lacustrine and riverine habitats in eastern Georgian Bay. We will randomly choose sites from the 26 quaternary watersheds identified in the McMaster Coastal Wetland Inventory (from French River to Giants Tomb Island) to collect information for both model building and validation. We will apply the HSM to produce a ranked habitat map that will identify essential areas that must be protected to conserve the two umbrella species. We will make sure that these maps are shared with local governments and environmental agencies so that protection for these habitats will be incorporated into official plans of townships in eastern Georgian Bay.