TORONTO — Aug. 23, 2010 — With more than 32,000 islands in its waters, the Great Lakes contain the world’s largest collection of freshwater islands, but these islands are dynamic, undergoing many changes that threaten the islands’ flora and fauna, including climate change, habitat degradation, invasive species and some natural processes, according to a new report published by scientists from leading conservation organizations in the United States and Canada.

 

The report, titled “Islands of Life,” ranks and describes the biodiversity (biological diversity) and threats to priority islands found in the Great Lakes. These islands provide essential habitat for migratory and nesting birds as well as rare plants and animals like the piping plover and Pitcher’s thistle, found nowhere else on Earth.

 

“This information has never been collected and categorized before,” said Dr. Patrick Doran, director of science in Michigan and the Great Lakes for The Nature Conservancy. “From conducting research and then analyzing the report, we learned that islands ranked highest in biodiversity are often also subject to greater threats from human activity. This helps us and others decide and prioritize our conservation action.”

 

Dr. Doran said that he hopes others will read and learn from the report to make more informed decisions about conservation acquisitions, practices and other strategies aimed at protecting the most vulnerable habitats for rare and declining species in the Great Lakes.

 

“No matter what side of the lakes you live on, what we do on land and in the water affects the health of this critical freshwater system,” said Chris Maher, regional vice president for the Nature Conservancy of Canada. “Partnerships like this help share our science and leverage the information so that we are collectively working together to ensure the health of the lakes and the islands within them that provide critical habitat for wildlife.”

 

The Nature Conservancy collaborated with the Ontario Ministry of Natural Resources, Natural Heritage Information Centre, Nature Conservancy of Canada, Great Lakes Program, University of Minnesota, U.S. Fish & Wildlife Service, and Great Lakes Islands Project to create the report.

 

Biodiversity of the islands was measured by the number of species, plant communities, ecological systems, and ecosystem functions, along with shape complexity, geological diversity, shoreline diversity, size, and distinctiveness. An island with a high biodiversity score may provide habitat for specialized plants, animals and natural communities. According to the report, the top 10 islands based on highest total biodiversity scores are:

 

 

Common threats to the islands include incompatible residential and cottage developments, tourism and recreation, marinas and resorts, increased road and building densities, increased access points for boats and other vehicles, incompatible agricultural practices and invasive species. According to the report, the top 10 most threatened islands are: