Change detection of wetland vegetation under contrasting water-level scenarios in coastal marshes of eastern Georgian Bay
Great Lakes coastal marshes are economically and ecologically important ecosystems that purify water, reduce flooding risks, and provide habitat for the most diverse community of plants, reptiles, and fish along the shoreline. Most of the coastal marshes in Lakes Ontario and Erie have been destroyed or degraded by land-use changes, but those in eastern Georgian Bay are still in pristine condition; however, water-level fluctuations associated with global climate change and human activities are threatening their ecological integrity. Beginning in 1999, water levels declined to abnormally low levels and remained low for 14 years. Uncharacteristically, this was followed by an abrupt increase in 2014 that have since continued to climb to record high levels in 2020. A survey of fish and plant communities from 2003 to 2019 showed that the quality of the fish communities have deteriorated between the two periods of contrasting water levels. Since the fish community is known to be dependent on the structure and function of the plant community, we hypothesize that the deterioration in the fish community can be attributed to a structural change in wetland vegetation.