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

Jonathan Midwood,Patricia Chow-Fraser,Daniel Rokitnicki-Wojcik

doi:10.5402/2012/950173

Abstract

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.

Highlights

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]
We have identified all coastal marshes in a region where complete data has been lacking and that have filled an important void in the distribution of coastal wetland habitat in the Great Lakes basin
By accessing a large collection of satellite imagery, we have been able to fill in major gaps in the Great Lakes Coastal Wetland Consortium Inventory along eastern and northern Georgian Bay that had been noted by the authors [10]

Summary

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]. As a signatory in 1981 of the Ramsar convention, Canada has an obligation to identify and protect ecologically important wetlands (http://www.ramsar.org/). 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 km. 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 [5,6,7]. In Ontario, majority of these wetlands have been lost or degraded as a result of human disturbance [8], except in the eastern and northern shore of Georgian Bay, where they are mostly in relatively pristine condition [9]

Methods

Results

Conclusion