Development of an Inventory of Coastal Wetlands for Eastern Georgian Bay, Lake Huron

Coastal wetlands of eastern Georgian Bay provide critical habitat for a variety of wildlife, especially spawning and nursery habitat for Great Lakes fishes. Although the eastern shoreline has been designated a World Biosphere Reserve by UNESCO, a complete inventory is lacking. Prior effort by the Great Lakes Coastal Wetland Consortium (GLCWC) was unable to fully identify coastal wetland habitat in eastern Georgian Bay due to limited data coverage. Here we outline the methodology, analyses, and applications of the McMaster Coastal Wetland Inventory (MCWI) created from a comprehensive collection of satellite imagery from 2002–2008. Wetlands were manually delineated in a GIS as two broad habitat types: coastal marsh and upstream wetland. Coastal marsh was further subdivided into low marsh (LM; permanently inundated) and high marsh (HM; seasonally inundated) habitat. Within the coastal zone of eastern and northern Georgian Bay there are 12629 distinct wetland units comprised of 5376？ha of LM, 3298？ha of HM and 8676？ha of upstream habitat. The MCWI identifies greater total wetland area within the coastal zone than does the GLCWC inventory (17350？ha versus 3659？ha resp.). The MCWI provides the most current and comprehensive inventory of coastal wetlands in eastern Georgian Bay. 1. Introduction Wetlands represent some of the most biologically diverse ecosystems on the planet, yet globally, estimates of wetland loss due to human development range from 50% to 90% [1]. Canada has approximately 25% of the world’s wetlands [2, 3]. As a signatory in 1981 of the Ramsar convention, Canada has an obligation to identify and protect ecologically important wetlands (http://www.ramsar.org/). To date, Canada has protected more wetland area than any other country, but the prevalence of wetlands in the Canadian landscape means that there are many wetlands that have not yet been delineated. In many regions of Canada, there is still an urgent need to catalogue and monitor wetlands [3]. The Laurentian Great Lakes, shared by Canada, and the United States, represent the largest freshwater resource in the world. A review of wetland research conducted in this region by Herendorf [4] identified over 1500 large coastal wetlands with a total surface area of 1700？km2. These marshes provide many important ecosystem services including water purification, nutrient sequestration, and shoreline buffering [1, 3], as well as important feeding and nursery habitat for a wide variety of organisms including fish, birds, invertebrates, mammals, and reptiles [5–7]. In Ontario, majority of these