Concentrations in the extreme western end of LIS were 

 almost invariably orders of magnitude higher than levels 

 in the eastern basin. Most of the northern Long Island 

 shoreline was also low in sediment heavy metals and 

 fecal coliforms. Deep waters in central LIS showed inter- 

 mediate values, while several areas near population and 

 industrial centers on the Connecticut coastline had levels 

 almost as high as were found at the western end. 



Sediment Organic Matter 



Distribution of sediment organic matter for Cruise 1 

 (Table 2) showed a pattern similar to that for the above 

 water and sediment constituents. Much of LIS, especial- 

 ly along the Long Island coast and in the eastern basin, 

 had <V"c organic matter in sediments. The highest 

 values were found from the station 7-10 transect (long. 

 73°40'W) west. Stations 1, 5, and 7 in westernmost LIS 

 had between 9 and lO'p organics in sediment. Highly 

 organic sediments were also found in a band between 

 long. 73°10' and 73°20'W, and in several other patches of 

 mostly deepwater, muddy sediments in the central 

 basin. Table 2 also indicates substantial between-cruise 

 variability in sediment organics at a number of stations. 



This is undoubtedly due in part to sediment patchiness 

 and/or station relocation inaccuracies. 



Benthic Macrofauna 



A list of all annelids, molluscs, and arthropods 

 collected during our most extensive (summer 1972) 

 sampling is given in Table 3. We identified a total of 248 

 species within these taxa, with annelids accounting for 

 469"c of the species, molluscs 21' c, and arthropods 33%. 



Shannon-Weaver species diversities (//') were 

 calculated for all 1972 samples. Distribution of H' values 

 is shown in Figure 39. An obvious feature of the H' distri- 

 butions is that lowest values (<1.0 bits/individual) were 

 found amost exclusively at deepwater stations with high 

 silt-clay content (compare with Fig. 38). Low diversities 

 in these areas were due mostly to a high degree of domi- 

 nance by several bivalve species, as will be discussed 

 below. In the central and western basins there was no 

 apparent reduction of H' values with the higher levels of 

 pollution found toward the western end of LIS. Highest 

 diversities, however, were found in the eastern basin, 

 which also had lowest contaminant levels. 



Table 2.— Organic matter in Long Island Sound sediments (weight percent). 



