13-19 



determined on the growth, mortality or commercial viability (as measured 

 by condition index) of experimental oyster populations within the New 

 Haven Harbor. 



TRACE METALS 



Trace metals enter New Haven Harbor from the Quinnipiac River, 

 major sewer outfalls located near Long Wharf and near New Haven Harbor 

 Station, as well as from the atmosphere. The dominant sources are the 

 sewer outfalls. New Haven Harbor sediments contain high metal concen- 

 trations relative to greater Long Island Soxind because of proximity to 

 discharges from several sewage treatment plants. Any contribution from 

 the New Haven Harbor Station discharge, surface runoff or settling pond 

 leachate would be relatively small and be obscured by contributions from 

 the sewer outfalls. 



Soft tissue of Crassostrea virginica showed lower levels of 

 trace metals in New Haven Harbor oysters than in five other Long Island 

 Harbors studied. Suspension and deposit-feeding molluscs showed slightly 

 higher zinc in New Haven Harbor, but lower copper relative to Long 

 Island Sound. C. virginica showed higher concentrations of these metals 

 than other bivalves analyzed including Mercenaria mercenaria and Mytilus 

 edulis. Trace metal concentrations did not show a pronoianced seasonal 

 or spatial pattern in Mercenaria mercenaria soft tissue in New Haven 

 Harbor . 



Impaats 



Impact from New Haven Harbor Station on the trace metal regime 

 in New Haven Harbor, if present at all, is overwhelmed by the ambient 

 long-term trace metal supply and removal patterns. 



