Silt covers eggs and deprives them of oxygen from the surrounding water. The eggs of bass, trout, minnows and other fish need clean gravel to hatch successfully. You might wonder how much difference a wetland makes in removing silt. Decide for yourself. Studies have shown that some wetlands remove 95 percent of the sediments in the water column by simply slowing the water velocity.
Wetlands clean the water in other ways, too.
Eutrophication is one of the biggest problems threatening our region's most precious resource-Chesapeake Bay. Years of land development, road construction, agriculture, forest removal and wetland filling have left our river's shores open to erosion. Silt and excess nutrients eventually wash downriver to the Chesapeake. But if we were smart, we'd leave the wetlands alone to do their cleanup job. Wetlands also provide food, vegetative cover and water.