For centuries, Stellwagen Bank has provided a rich and productive fishing ground. Fishing fleets caught Atlantic cod, haddock, silver hake and yellowtail flounder, as well as Atlantic blue fin tuna, large sharks, and schools of herring. About fifty years ago it became evident that the resources, increasingly depleted by centuries long fishing, could not be easily replenished. Nevertheless, commercial fishing continues, under stringent regulations, for fish and shellfish, including lobster, sea scallops, squid, and ocean quahogs. As well, recreational fishermen fish for blue fin tuna and striped bass.
In 1992, the United States Congress authorized the establishment of Stellwagen Bank and the surrounding area as the Stellwagen Bank National Marine Sanctuary. The sanctuary includes Stellwagen Bank, Tillies Bank northeast of Stellwagen Bank and southern portions of Jeffreys Ledge to the north. It is located approximately eight hundred forty-two square miles along the eastern edge of Massachusetts Bay, six miles north of Provincetown, twenty-six miles east of Boston, and seven miles southeast of Cape Ann. The centerpiece of the sanctuary is Stellwagen Bank, a shallow, glacially deposited, sand and gravel underwater plateau. Formed during the last great ice age, the area is scattered with ridges and troughs. Water depths over and around the bank range from sixty-five feet to more than three hundred feet. Seaward, east of the bank, the sea floor slopes to depths of six hundred feet or more.
The rich waters are a result of its geology and water dynamics and provide essential habitat for an unbelievably wide array of marine creatures. Upwelling currents occur, caused when waters deep in the Stellwagen basin, to the west, and the Gulf of Maine encounter the topographical features of the Bank’s rising elevation. These currents mix nutrient rich bottom water with sunlight-infused surface water. This combination of sunlight, nutrients and carbon dioxide create a condition in which phytoplankton thrive. Phytoplankton converts sunlight to energy in a process called photosynthesis and zooplankton feed on the phytoplankton blooms. Thus begins the chain of productivity supporting the incredibly rich marine life.
Areas within the sanctuary support young fish and shellfish, cod, flounder, sea clams and lobster as well as vast number of invertebrates. Of particular importance is the wealth of sand lance, which burrows into the coarse sandy bottom of the Bank to avoid predators. Forming schools of thousands, these calorie rich fish provide high nutrition for the endangered northern right whale, humpback whale, fin back whale, larger fish and sea birds that feed in these waters all summer.
During the second half of the twentieth century the area gained fame as a whale watch destination. Species such as the humpback whale, fin whale, minke whale, northern right whale, Atlantic white-sided dolphin, harbor porpoise, pilot whale, and harbor seal are regular visitors.