Eelgrass has another problem in Chesapeake Bay, and that is waterflowl. Before the impact of human population pressure, there were migrating geese. With people came the semi domestication of resident geese. Studies of the diet indicate that tons of eelgrass are consumed on a daily basis all summer long, where it used to be a fall migration phenomenon. Geese incidently add fecal coliform and bio available nitrogen year round. In favor of the geese, though, they have short enough necks for some of the grass to survive in the deeper water, as long as it is clear enough. Then came the mute swans. Swans can graze so deeply that the geese are getting stressed. The birds don't mind the juvenile crabs, I don't know if they eat them. Then we have the imported nutria eat the marshes that filter upsteam. Controlling invasive species would help sequester a considerable amount of carbon as well as improve water quality.