11-53 



ecticut DEP show that several kills , involving tens of thousands of 

 menhaden, occurred in New Haven Harbor during the summer of 1974. Simi- 

 lar, but poorly documented events have occurred nearly every year in the 

 present decade. Connecticut occurrences have been attributed by Conn- 

 ecticut DEP staff to pollution by industrial and municipal wastes 

 and/or low ambient dissolved oxygen concentrations. These mass mortal- 

 ities are not confined to New Haven Harbor, but occur in estuaries all 

 along the Atlantic coast with varying severity and frequency and are 

 prevalent in pristine waters as well as polluted. 



Substantial impingement of menhaden on traveling screens of 

 New Haven Harbor Station was first detected in Jiine 1976 and continued 

 through December of that year (Figure 11-18) . Before and after this 

 period, however, impingement of menhaden was negligible. At its peak, 

 during the third and fourth week in July 1975, the New Haven Harbor 

 Station impingement rate averaged more than 600 juvenile menJiaden per 

 day. This was approximately four times the highest impingement rate for 

 this species at Devon, a smaller generating station on the Housatonic 

 River which utilizes about 50% as much cooling water as New Haven 

 Harbor Station. The problem is of lower magnitude at most other power 

 plants in the Long Island Sound area. Menhaden impingement has been 

 much greater at Salem and Bray ton Point, MA; Astoria, NY; Surry, VA and 

 Brunswick, NC (Stupka and Sharma, 1977) . Also, to put impingement 

 losses in their proper perspective, it should be recalled that menhaden 

 typically die by the tens and hundreds of thousands during "fish kills." 

 Resulting dead fish may be drawn onto the traveling screens by the 

 intake currents, where they are counted as impinged fish. 



Menhaden become sexually mature around age III when they are 

 over 18 cm long (Westman and Nigrelli, 1955) . In Long Island Sound, 

 spawning occurs from May through October, with peaks of larval abundance 

 in June, July or September (Wheatland, 1956; Richards, 1959). Recent 

 evidence from Port Jefferson, Glenwood (LILCO, 1978) , and New Haven 

 Harbor ichthyoplankton collections support these observations. New 



