8-20 



Asterias forbesi 



The common starfish, Asterias forbesi, has been the second 

 most abundant species collected in epibenthic trawls. It ranges from 

 Cape Cod Bay to Cape Hatteras and is common from the littoral zone to 

 approximately 49 m (Gosner, 1971). Asterias, although primarily a 

 predator of bivalve molluscs, will consume fish or almost any other 

 organisms that it can capture. Hardy (1965) indicated that starfish in 

 general are perhaps the most voracious of the invertebrate carnivores. 

 During the period 1966 to 1969 the starfish, Asterias forbesi, was cited 

 as the most important cause of oyster mortality in Long Island Sound 

 (MacKenzie, 1969) . In unprotected areas, starfish can reduce a commercially 



viable set of oysters to noncommercial levels in weeks . Under controlled 

 laboratory conditions adult starfish have been observed to eat an average 

 of five oysters each per 28-day period in water having an optimal tempera- 

 ture for feeding (20°C) (MacKenzie, 1969) . 



In New Haven Harbor, the abundance of starfish has steadily 

 declined since 1974 when 17,000 individuals were collected (25% of the 

 total catch) (Table 8-3 and 8-4) . Numbers decreased to 7800 collected in 



1975 (7% of the total catch) and 2700 in 1976 (4% of the total catch) . 



The trend continued in 1977, when the total 9-month catch (630 individuals) 

 decreased by 60% from that recorded during the same 9-month period in 



1976 (2100 individuals) . A consistent decline was observed at all 

 stations in the harbor. 



Long-term fluctuations in the abundance of starfish are well 

 documented (Galtsoff , 1964) . High yearly abundances are often followed 

 by years of relatively low nximbers . Such fluctuations are attributable 

 to variations in survival of planktonic larvae as well as larval setting 

 success (Galtsoff and Loosanoff, 1939). It is likely that the decline 

 in abundance of starfish in New Haven Harbor here reported was a result 

 of such natural fluctuations. This conclusion is further supported by 

 the fact that monitoring data collected in New Haven Harbor since 

 October 1977 revealed an upward trend in starfish abundance during 1978, 



