10-26 



Feng and Ruddy (1974) made a detailed study of the composition 

 of the soft tissue of oysters {Crassostrea virginica) harvested along 

 the Connecticut coast. A single stock of oysters obtained as yearlings 

 were transferred to six stations on the Connecticut coast: (1) Norwalk 

 Harbor at the Northeast Utilities Company pier, (2) Bridgeport at the 

 Pleasure Beach Bridge, (3) the Housatonic River below Devon, (4) New 

 Haven Harbor at the Coast Guard Station finger pier, (5) New London 

 Harbor at the U.S. Navy Underwater Systems Center pier and (6) Noank at 

 the University of Connecticut Marine Sciences Institute pier. The stock 

 was then sampled periodically between June 1972 and April 1974 and 

 tissue analyzed for Cd, Cu, Hg, Mn and Zn. The oyster tissue did not 

 vary significantly in the concentration of these elements from the 

 native oysters also analyzed. The highest values for all of the trace 

 elements except mercury are found at the Bridgeport and Housatonic 

 sites. 



Figures 10-13 - 10-15 show the changes in composition with time, 

 at each of the six locations, for Zn, Cd and Cu, respectively. There is 

 clearly a marked increase from the summer of June 1972 to the winter of 

 1974 for the Housatonic-Bridgeport region for all metals and a marked 

 increase for zinc for all other locations except Norwalk which seems to 

 have gone through a maximum in the winter or spring of 1973. 



Mussels 



Trace metals in Long Island Sound mussels were determined at 

 Yale University (Curran, 1976 and additional data)*. A map of the 

 sampling locations is shown in Figure 10-16. The geographic variations of 

 trace metals in native mussels collected in 1975 show (Figures 10-17- 10-21) 

 the same patterns as the oysters although the concentrations are con- 

 siderably lower in the mussels. The pattern holds for all the trace 

 metals analyzed including Pb and Ni as well as Zn, Cd and Cu. The other 

 region of high metal concentration in the mussels is the area around 

 Throgs Neck. 



* 

 The analytical methods used at Yale have been reported in the 1975 Annual 



Report to the United Illuminating Company through Normandeau Associates, Inc. 



