sediments averages about 2% (Hough, 1940). Gilbert et al. (1973) 

 found that sediment organic content ranged from 0.88% to 6.65% 

 throughout the Bay. Driscoll (1975) found that the mean annual 

 total organic content of the sediment in the northwest portion of 

 the Bay ranged from 0.48 to 3.20% (Table 5). Of this, 0.11 to 

 0.97% was total organic carbon and 0.026 to 0.147% was total 

 organic nitrogen. The concentration of carbonates ranged from 3.91 

 to 11.44%. The levels of all three organic parameters are 

 inversely related to grain-size. The carbonate content of the 

 sediment was also generally greater in finer sediments. Minimum 

 organic values occurred in mid-winter, values peaked in late 

 July/early August (Figure 9) . Carbonate also peaked in the summer, 

 with a secondary peak occurring in November/December. Driscoll 

 (1975) concluded that these seasonal patterns in sediment organic 

 concentrations were due primarily to changes in the abundance and 

 activity of benthic microorganisms. 



4.3 Chemical Implications for Dredged Material Disposal 



Given the generally well-mixed nature of the water column 

 in Buzzards Bay, dilution of low-levels of dissolved pollutants 

 seems probable. Excluding the entrance to New Bedford Harbor, 

 sediment-associated contaminants, both metals and organics, show 

 no distinct spatial gradients in the Bay. The only data available 

 for the sites within the Buzzards Bay region are from 1973. 

 Sediment chemistry data from this area subsequent to the disposal 

 occurring from 1979 to 1984 might show elevated contaminant levels 

 depending on the source of the dredged material. However, as 

 indicated by the baywide chemical data as well as the physical 

 data, there was no evidence that contaminants were influencing 

 regions away from the disposal areas (both Buzzards Bay Disposal 

 Site and Fairhaven) . 



Aspects of bioaccumulation and the introduction of 

 contaminants into commercial species are discussed in section 5.3. 



5.0 BIOLOGICAL CHARACTERISTICS 



Much of the pioneering work regarding animal-sediment 

 interactions in shallow water marine ecosystems has been carried 

 out in Buzzards Bay. This research has important biological, 

 sedimentological, and disposal management implications. An 

 overview of this extensive literature is presented below. 



5.1 Benthos 



Sanders (1958, 1960) performed extensive quantitative 

 benthic sampling programs in Buzzards Bay. These data showed that 

 average macrofaunal benthic population densities in Buzzards Bay 

 were 2-4 times less than similar assemblages in Long Island Sound. 

 Low water column nutrient and chlorophyll levels in Buzzards Bay 



