Stellwagen Bank was designated as a national marine sanctuary for its long history of human use and its high natural productivity. It is one of the most biologically diverse areas in the Gulf of Maine and includes a wide range of habitats affected by four distinct seasons. Stellwagen Bank, the central geographic feature of the sanctuary, is an important factor in directing water movement in Massachusetts Bay. Located just a few miles from Boston and other New England ports and harbors, the bank's accessibility, surrounding features, and living and cultural resources have made this area a prime destination for marine research and recreation such as wildlife watching, diving, boating, and fishing. The heavy vessel traffic in these waters has inevitably led to accidents; the sanctuary seafloor is a repository for many shipwrecks.