MATERIALS AND METHODS 



Contemporary oceanographic techniques for non-contaminating sampling and 

 sample handling were employed, along with clean-laboratory techniques for low- 

 level metal analyses. Table 1 lists the specific procedures followed to 

 ensure accurate work. 



Seawater samples were collected on February 25, May 13, July 26, 

 September 23, and December 20. Sampling times and tidal stages are listed in 

 Table 2. Molluscs were collected on February 26, May 14, July 24, Sejjtember 

 24, and December 20. 



Sai;iple Collection. 



1 ) Seawater 



Collection was accomplished off the bow of the vessel while it made 

 slight headway into uncomproinised waters. A two meter PVC sampling pole with 3 

 one-liter CPK bottles taped to one end was plunged through the surface layer to 

 about 0.5m depth. The bottles collected three samples from a swath about 30cm 

 wide; if the water mass were completely homogeneous the three samples would be 

 exact replicates. The bottles were allowed to half fill for a rinse, then were 

 submerged again for the sanple. Adjacent water temperature was noted during 

 filling. The position of the cooling water plume is readily detected by 

 temperature anomalies; in this past year, the plume itself was not sampled. 

 About 250 mis of seawater from each sampling bottle was immediately filtered 

 through 0.45 micron Nuc lepore membranes held in a Millipore filtering 

 apparatus. Each filtrate was collected in a CPE storage bottle, and was 

 acidified to pH 2 with concentrated HCl. The used membranes were stored in CPE 

 vials . 



Samples were taken at the quarry cut, near Twotree Island (outside the 

 obvious temperature anomaly of the plume), in front of Millstone Intake #1, and 

 at fjiant's Neck, during mid-ebb tide stage. 



2) Molluscs 



Oysters were deployed in mid-January, 1982, in cages made of vinyl-coated 

 wire, at White Point, at the Northeast Utilities Environmental Lab (NUEL) dock 

 near Fox Island, from the floating laboratory in the quarry, and at Giant's 

 Neck. A natural population that grows on the steel frame of the floating 

 laboratory was also sampled on each occasion. 



On each sampling occasion, three replicate groups of 8 oysters were 

 collected from each site (three groups of 4 individuals were taken from each of 

 two cages). It was possible to collect only three to eight individuals at any 

 time from the natural population. These were divided into two or three 

 replicates, but with so few individuals, such replicates can be expected to 

 show larger inter-group variability than those from the exposure cages. Three 

 replicate groups ot fifteen individual mussels were collected from the rocky 

 intertidal zone at Giant's Neck, at Fox Island South (adjacent to the effluent 

 discharge at quarry cut), and at Fox Island North (opposite the NUEL Dock). 



The molluscs were scrubbed on-site with nylon brushes, in local seawater, 

 then placed in bags and put on ice. At the end of the day, the molluscs were 

 deefi-frozen until processing. 



