We've been bringing you reports from the series, Ten Threats to the Great Lakes, which is now looking at the threat to beaches. The Great Lakes Radio Consortium's Lester Graham reports that scientists are beginning to understand what's killing thousands of Great Lakes shorebirds, and how it might be part of a larger problem indirectly caused by humans.

In our next report in the Ten Threats to the Great Lakes series, we continue to look into polluted beaches. The Great Lakes Radio Consortium's Shawn Allee reports on Great Lakes beach closures and how they are related to dangerous levels of bacteria in the water.