8-43 



difficult to draw any definite conclusions as to the downward trend in 

 starfish abundance in New Haven Harbor, it is doubtful that the observed 

 decrease was in any way related to operation of the Harbor Station 

 electric generating facility. The decline in starfish abundance first 

 became apparent in March 1975, prior to the time that the Harbor Station 

 went on-line (NAI, 1976a) . Also, it is well documented (Galtsoff , 1964) 

 that long-term fluctuations in starfish abundance occur: high yearly 

 abundances are often followed by years of relative scarcity. Treatment 

 of oyster beds in the harbor by mopping and with biocides also affects 

 starfish abundance. Finally, the decline in starfish abundance was 

 apparent at all stations sampled, including stations with low impact 

 likelihood (Stations 13, 19 and 20), and no substantial changes in dis- 

 tribution were evident. 



Rank of abundance by station, annually for the 12 most common 

 epibenthic invertebrates, is presented along with annual species abun- 

 dance by station in Table 8-3. Judging from annual abundance and sta- 

 tion rank by year for each of the 12 selected species, it is evident 

 that only minor variations in species distribution occurred between 

 preoperational and operational years. These variations are probably pri- 

 marily attributable to the mobility of epibenthic invertebrates as well 

 as natural fluctuations in abundance and vicissitudes in catch success. 



Variations in rank of abundance for all twelve species were 

 notably small in the area of the thermal discharge (Station 8) . In no 

 case did species abiindance and/or station rank indicate major changes in 

 distribution. This is particularly important since Station 8 would be 

 expected to have the greatest potential for manifesting direct effects 

 of the discharge. 



Several species of epibenthic invertebrates have been impinged 

 on the traveling screens of the cooling-water intake system. Cancer 



irroratus , Ovalipes ocellatus and Squilla empusa were impinged in high- 

 est abundances (Table 8-5). Impingement of Cancer was high only during 

 October and November 1975 (average of 200 per 24 hours) . Since that 



