The Great Lakes Radio Consortium (GLRC) produced a series of radio reports in late 2005 covering what they considered their top ten threats to the Great Lakes. The whole series is online and available at the link above. These ten can be summarized into a top five list:
- Invasive species — Invasive species are organisms that are found in ecosystems from which they did not originate. Many of them often out-compete, eat, or otherwise harm other native organisms.
- Pollution — Non-point source pollution is created when water from rain or melting snow carries pollutants as runoff into waterways and groundwater. The pollution is usually a mix of chemicals, including those coming from agricultural and urban sources. Point source pollution comes directly from an identifiable source, like a wastewater discharge pipe from a factory.
- Wetlands — Wetlands are often called the kidneys of the earth because they filter and extract pollutants from the water that passes through them. They also alleviate flooding and control erosion.
- Cargo ship ballast — The Great Lakes are linked to the world’s ports through a system of channels, locks and dams stretching from Duluth, MN to the Gulf of St. Lawrence – a 2,340 mile journey. Improper handling of cargo ship ballast is the current threat.
- Water withdrawals / diversions — The demand for fresh water is high, and the Great Lakes are a tempting and ready source. Many people and organizations outside the Great Lakes basin are seeking to make withdrawals from the Lakes.