Muddying the Waters – Background
Sediment, small particles of soil and other materials, is one of the most damaging pollutants in the Bay. Sediment enters the water through runoff from eroding soil. When suspended in the water, sediment prevents sunlight from reaching underwater grasses. This suspended sediment can also clog the gills of fish. As sediment settles to the bottom, it can smother the organisms that live there. In the worst cases, high levels of sediment in the water can actually change the physical structure of a waterway.
Sediment can best be reduced by erosion-control measures. Hay bales and filter cloths can be used to keep exposed soil in place. Vegetated buffer zones around properties that line waterways filter sediment from runoff before it reaches the water.
This activity helps students to investigate the properties of sediment in water. It provides students with an understanding of sediment's impact on the Bay and illustrates the connection between human activity on land and water quality in the Bay.