Regulations and Natural Barriers Limit Invasive Species in the Great Lakes
The Great Lakes have been a hotspot for invasive species, with over 180 non-native species recorded. However, most of these species fail to establish lasting populations. Regulations requiring ocean-going ships to treat ballast water with saltwater have significantly reduced new invasions. The harsh climate of the Great Lakes, with cold winters, also acts as a natural barrier, preventing many warm-water species from surviving. Additionally, the unique chemical composition of the lakes, such as low calcium levels in Lake Superior, inhibits the establishment of certain species like zebra mussels.