One of the species that makes the Chesapeake Bay famous is the Blue Crab. This species is a scavenger, feeding on any species that dies on the oyster bar or other places in the Bay or river. The crab will also feed upon small fish or even other crabs if it can catch them. Since the oyster population has declined, many watermen have started to catch crabs to help them to make a living. Some scientists fear that crabs may start to decline in number if we begin to catch too many. During the winter months crabs will migrate down the rivers into the Chesapeake Bay, where they will spend most of the cold winter buried in the mud. As the water temperatures begin to warm up in spring, the crabs will crawl and swim their way back up the rivers and creeks.