The world’s rivers carry billions of cubic yards of sediment – sand, silt and other material – and transport it to wetlands and coastal areas. Until fairly recently, this was viewed as a negative thing. But that has changed.
There are an estimated 84,000 dams in the United States which impound 600,000 miles of river, or about 17% of the rivers in the country. Within the next 15 years, more than 90% of the world’s rivers will be fragmented by at least one dam.
One doesn’t have to travel far in Downeast Maine to see what over-fishing can do to coastal villages and the people who work there. First the cod disappeared, then the herring, and finally the sardines.