Wetlands filter waterSince wetlands are able to slow down flowing water, they also act like a filter for soil particles, or sediment. Sediments that are carried with the flowing water have time to settle out of the water as it slows and is trapped by stems and roots of the wetland plants. This is an important function because too many sediments in our waterways can cause fish to suffocate--especially in shallow areas where young fish may live and adult fish lay eggs. Sediments also become a problem over time for harbors and passageways that fill in with the excess dirt. Removing all of that soil from the bottom of a waterway is a very expensive solution!
Wetland plants act as good filters for other water pollutants as well. Because they are a middle ground between land and the Bay, they can catch and hold toxic chemicals and excess nutrients like nitrogen and phosphorous, which can all be harmful to fish and underwater grasses.