the DAMOS Mussel Watch Project was concerned with the following 

 questions: 



1. Is there any evidence suggesting that increases in trace 

 metals and polychlorinated biphenyls (PCBs) in Mytilus edulis 

 were associated with on-going open water disposal of dredged 

 materials? 



2. Is there any physiological change, e.g., tissue wet/dry 

 weight ratios, gonadal development in M;. edulis that could be 

 attributable to the increase in tissue trace metal and PCBs 

 concentrations? 



3 . Is there any discernible histopathological change that 

 could be correlated with the increase in tissue trace metal and 

 PCBs concentrations? 



Experimental 



Field Operations 



Monitoring at the WLIS disposal site was initiated in June 

 1984 with the deployment of three experimental platforms (WLISrN, 

 WLISc and 500MW) and a master reference platform (Rlr) (Fig. 4) . 

 Our original plan of using Latimers Light mussels as a source 

 population stock had to be modified due to the lack of mussels of 

 the required size class (>2.5 cm) sufficient to stock the four 

 platforms. An older mussel population from Ram Island Reef, 

 which generally exhibited similar trace metal concentrations as 

 those found in the Latimers Light population, was found in 

 sufficient numbers for our purpose . More than 6,000 mussels were 

 collected from this location, sorted, counted, bagged and held 

 briefly at the Marine Research Laboratory dock until they were 

 deployed at the three experimental stations. The rationale of 

 using one population of mussels as sentinel organisms for all 

 disposal site stations has been discussed in our previous reports 

 (Feng, 1984, 1985). 



The deployment of the three mussel monitoring platforms at 

 western Long Island Sound was accomplished on June 27, 1984 at 

 (1) the center of the disposal mound (WLISc) , (2) 500 meters west 

 of the mound center (500MW) and (3) a reference station located 

 2.22 kilometers south of the mound (WLISrN). On the following 

 day, June 28, 1984, a platform was also deployed at Ram Island 

 Reef (Rlr) serving as a master reference station for the other 

 three stations. Each platform was stocked with 1350 mussels in 

 27 mesh bags (50 mussels per bag) . Details of the field 

 operation are summarized in Table 2 . 



