Review of the oceanography of Long Island Sound 225 



during the late nineteenth and early twentieth centuries, and all available observations 

 have been summarized by Le Lacheur and Sammons (1932). 



The first oceanographic studies that may be regarded as modern in their general 

 scope and outlook were begun in the 1870's under the able direction of Spenc er F. 

 Baird, U.S. Commissioner of Fish and Fisheries. For the waters from Cape Cod to 

 New Jersey, and including Long Island Sound, we find in his reports during the ensuing 

 years not only accounts of the fishes and their physical environment, but also mono- 

 graphs on the invertebrates (Verrill, 1873) and algae (Farlow, 1879), as well as 

 other major works that are still in common use. 



In 1935 the U.S. Fish and Wildlife Service established a laboratory at Milford, 

 Connecticut, under the directorship of Victor L. Loosanoff. One of the most 

 important contributions of this laboratory has been a thorough study of lamellibranch 

 physiology and ecology by combined field and laboratory techniques. In addition, 

 records have been maintained for fifteen to twenty years of temperature and salinity 

 in the north-central part of the Sound, oyster spawning and setting, and other oceano- 

 graphic matters of both practical and scientific interest. 



In 1938 the Bingham Oceanographic Laboratory began a year's survey of plankton 

 and associated environmental factors in the same area (Riley, 1941), and similar 

 work was carried on during the summers of 1940, 1941, and 1950. A program of 

 broader scope was instituted in 1952, consisting of weekly coverage of a grid of stations 

 in the central part of the Sound for a two-year period, followed by a further expansion 

 to coverage of the Sound as a whole at approximately monthly intervals. The latter 

 work is still in progress. 



The present paper reviews some of the work that has been done and attempts to 

 extract some ecological generalizations that will be applicable to Long Island Sound 

 in particular and perhaps in some cases to temperate littoral waters in general. For 

 purposes of comparison it is pertinent to mention other work in nearby waters: a 

 survey of temperature and salinity distribution by the Woods Hole Oceanographic 

 Institution in the area from Woods Hole to the central part of Long Island Sound in 

 1946, a study of Block Island Sound from 1943 to 1946 and in 1949 by the Bingham 

 Oceanographic Laboratory, and the work of Ryther (1954) and other Woods Hole 

 staff members in the bays on the south shore of Long Island. 



PHYSIOGRAPHY AND PHYSICAL OCEANOGRAPHY 



Long Island Sound (Fig. 1) is a semi-enclosed body of water some 90 nautical miles 

 long, with a maximum width of about 15 mi. and an area of 928 sq. mi. The maximum 

 depth in the eastern end is about 100 m. There is little water of more than 35 m in 

 the central and western basins, and the mean depth of the Sound as a whole is only 

 20 m. Free interchange with the waters of Block Island Sound occurs through a 

 series of passes at the eastern end. In the west there is more limited interchange with 

 the New York harbour and river waters. 



The drainage basin is roughly eleven times the area of the Sound, and the annual 

 volume of freshwater drainage averages 35 % of the volume of the Sound. However, 

 three-quarters of the river water enters the relatively open eastern end, where it is 

 flushed out rapidly and has a minimal effect on the Sound as a whole. 



Tidal interchange totals 8-6% of the volume of the Sound below mean low water, 

 leading to currents of three knots or more in the eastern passes and a maximum speed 

 I 



