It's not just because they're great for ducks and geese. Natural scrubbers going down the ditch on today's EnvironMinute.
Wetlands act as huge natural filters.
They remove excess nutrients and pollution from the rain water. But around the Chesapeake Bay, farming takes precedence. People have built thousands of miles of drainage ditches to keep the land dry enough for farming. Ditches can't remove nutrients from the water. The natural vegetation and trees that normally act as filters are gone, and that means that huge amounts of nutrients are dumped into the Chesapeake Bay.