The salt marsh is a transitional area between land and water systems.
Salt marshes are critical nursery areas for fish and invertebrates .
Some fish who live in the open ocean return to the salt marsh to feed there. Many fish breed here and use the salt marsh as a nursery. Peat, a collection of decomposed plant material and roots, acts like a filter. It helps to purify fresh water runoff from the upland region. In addition this dense material captures nutrients that are brought in with the ocean tides.