With the Great Lakes containing 18% of the world's freshwater, the river's that feed the Lakes are of global significance. Draining into the Great Lakes, the health of these rivers are obviously linked to the region's ecological and economic well-being. They continue to be threatened by pollution, shoreline development, overfishing, the invasion of exotic species, and recreational impacts. Some rivers in this region drain into the mighty Mississippi River Basin, the largest river basin in the US that drains 41% of the continuous United States.
