9-27 



built back up in the tissues. In a study of condition of C. virginica 

 from Pearl Harbor, Hawaii, Sakuda (1966) found a typical seasonal pat- 

 tern with high values during December, January and February (CI=6-7.7) 

 and low values during June, July and August (CI = 2-4) . He attributed 

 the very low condition indices of oysters from some beds to unfavorable 

 environmental conditions, primarily excessive silting. Ogle et al . 

 (1977) in a transfer experiment designed to detect the effect of depth 

 on oyster growth also detejrmined a seasonal pattern for condition index 

 e.g., high in June 1973 (13.2-15.5); low in December, 1973 (5.0-7.0) higher 

 in March 1974 (7.9-10.8) and low in June 1974 (1.3-2.2). The authors 

 explain the high condition indices in June of 1973 as due to a lack of 

 spawning because of transfer. 



Dry weight condition indices in this study ranged from 8.5 to 

 15.6 in May/ June for initial controls to 6.9-14.6 in November/December 

 at Harbor Station and 11.0-16.0 in November/December at Fort Hale. 

 These condition indices are generally higher than those in the studies 

 of both Sakuda (1966) and Ogle et al . (1977). Seasonal patterns are not 

 as well defined in the New Haven data because of the range of condition 

 indices recorded. Low condition indices at Harbor Station relative to Fort 

 Hale were consistently low both during pre- (1973-1974) and post- (1976- 

 1977) operational studies at the Harbor Station site. It is therefore 

 likely that these low indices are more a reflection of the greater 

 environmental impact in the inner harbor from various sources other than 

 from plant operation. In 1967 the FWQA conducted water quality investi- 

 gations in New Haven Harbor and concluded that the inner harbor area was 



grossly polluted. They measured dissolved oxygen levels of 4.0 mg/1 and 



5 4 



total and fecal coliform densities in excess of 10 and 3.6 x 10 /lOO 



ml, respectively. Data from the current study indicate a range of 



dissolved oxygen measurements in the harbor of 2.5-14.5 mg/1. Even in 



the outer harbor total coliform counts were above standards and sewage 



sludge deposits exceeding 6 inches in depth were prevalent in the area 



(reported in Army Corps of Engineers, 1973) . Laboratory tests have 



shown oysters to take up 2.5-5.0 mg/hr of oxygen (Galtsoff, 1964), so it 



is possible that at some concentrations recorded in New Haven Harbor 



this rate of uptake could not be maintained. As filter feeders, oysters 



