Sea couch is the marine version of couch grass. Home owners are not happy with couch grass in their yard because it is so aggressive. Sea couch has the same quality. It is capable of storing nutrients during the winter in its root stocks, thereby retracting these materials for other species. Sea aster is one of the few salt marsh plants which is not displaced. With the present increasing air pollution, sea couch is expected to dominate the marsh vegetation. Grazers eat the young shoots but shun the tougher older plants.