The many coastal wetlands around Georgian Bay and Lake Huron are the source of life and habitat for so much of what is considered special in this area. These highly productive ecosystems support a high diversity of freshwater species and are key to a healthy environment. With more than 8,000 km of shoreline on The Bay and 3,700 aquatic marshes in Eastern and Northern Georgian Bay alone, these areas provide high quality habitat for fish, amphibians and reptiles, insects, birds, waterfowl, a variety of other land-based wildlife, as well as numerous in-water and coastal plant species. The Great Lakes support more than 3,500 different species, approximately 80% of which rely upon The Bay’s coastal wetlands.
These living creatures and organisms depend on coastal wetlands for a variety of activities essential to life and survival, including spawning, nurseries, food and foraging, shade, shelter, cooler temperatures, and refuge from predators. When the wetlands change due to major and sustained changes in water levels, contaminants, agricultural development, urbanization or invasion by non-native species, so does the diversity and composition of the native ecosystems and all the species they contain. The entire system is delicately balanced, and it does not take much to upset that fine balance. Wetlands are highly vulnerable to extremes, such as variations in temperature, precipitation, and evaporation. If water temperatures or pollutant levels rise, for instance, or if marshes turn into dry meadows, bush or forest, they can no longer support the same biodiversity. In many instances, the changes are both transformative and permanent.
In addition to their critical habitat functions, wetlands also play an important role in maintaining overall water quality. Wetlands perform a type of water treatment function, filtering sediments as well as contaminants such as pesticides from the air and water, which helps to control water pollution. They also filter excess nutrients, reducing harmful concentrations of phosphorous and nitrogen. Wetlands help to protect against flooding and can control shoreline erosion and infrastructure too.
Most wetlands in the Great Lakes have already been lost or degraded due to human disturbance. More than 50% of wetlands in Lakes Michigan, Erie and Ontario have been negatively affected. But in Lakes Superior and Huron, including Georgian Bay, over 70% have been minimally impacted. Although Georgian Bay’s wetlands experienced some loss in surface area between 1986 and 2010, they remain abundant and in pristine condition, and are considered to be the least human-disturbed wetlands on the Great Lakes.