13-14 



Analysis of changes in abundances of the fourteen characteristic species 

 indicated that nine species showed significant increases in abundance 

 over the period of the study, and no species decreased in abundance. 



Similar statistical tests on the diversity values indicate 

 that no statistically significant changes in diversity were found over 

 the course of the program. All of the data-analysis results indicate 

 that there has been no significant change in the structure of the ben- 

 thic infaunal communities of New Haven Harbor due to the operation of 

 New Haven Harbor Station. 



INTERTIDAL INFAUNA 



Spring and fall sampling along three transects were utilized 

 to monitor the intertidal habitat (over 600 acres) in New Haven Harbor. 

 During seven years of sampling, a total of 90 invertebrate taxa were 

 collected. Soft-shell clams (Mya arenaria) , sandworms {Nereis succinea) , 

 gem clams (Gemma gemma) , mudsnails {Ilyanassa obsoleta) , macoma clams 

 (Macoma balthica) , barnacles (Balanus improvisus) , spionid worms (Spio- 

 nidae) , horseshoe crabs {Limulus polyphemus) and capitellid worms (Capi- 

 tellidae) were commonly collected, although individual and total organ- 

 ism densities varied substantially from year to year. Except for horse- 

 shoe crabs, mud snails and some polychaete worms, most of the abundant 

 taxa are sessile infaunal organisms that settle predominantly in the 

 Slammer. Overall density variation was most pronounced at East Shore and 

 Long Wharf, reflecting large fluctuations in soft-shell clam density. 

 Species richness was also highly variable and showed no annual trends. 

 Seasonal patterns in richness and organism densities were both usually 

 greater in fall than spring, due to spring and siommer recruitment and 

 winter mortalities. Of the three stations sampled, Sandy Point had the 

 greatest numbers of species and organism densities, while East Shore 

 usually was lowest for both parameters. 



