The Bottom Community of Ipswich Bay, Massachusetts

Abstract

The marine communities of Cape Ann, Massachusetts, were studied during the summer months of 1933 to 1938 inclusive and in 1940. Intensive bio-ecological studies were made on the intertidal communities of a narrow tidal inlet which cuts through the Cape Ann promontory. In order to relate the communities of this inlet to those of the surrounding region, a general survey was made of the bottom communities occupying the rim of coastal waters surrounding Cape Ann. This report is concerned with that particular phase of the field work. Dredgings were made in the bays of Cape Ann during the summers of 1934 to 1937 inclusive and in 1940. Altogether, 58 dredge hauls were made in Ipswich Bay, 19 in Sandy Bay, 9 along the eastern shore of Cape Ann, and 2 in Gloucester Harbor. This report is confined to the bottom community of Ipswich Bay inasmuch as it is the one which is best known. The bottom organisms were collected with a naturalist's dredge operated from either a dory or a sailboat propelled by an out-board motor. For the most part dredgings were made in depths between 12 and 80 feet at mean-low-water. Records were kept of each individual dredge haul for all except the first season. Two types of bottom were recognized, (1) hard sand and (2) rocky bottoms. Supplementary observations were made from a diving helmet during the seasons of 1935-1937. While the helmet was used most often in the tidal inlet, several dives were made in the shallow margin of Ipswich Bay to a depth of about 20 feet