local infaunal community had fully responded to the changing conditions. 

 Communities at all other subtidal stations, including those potentially 

 impacted by power plant operation (EF and JC) , exhibited similarities in 

 density, species composition and trophic structure during 1983. Although 

 differences occurred in the actual ranking of the dominant species, several 

 were common to all stations. 



Temporal differences at potentially impacted vs non-impacted stations . 



In 1983, seasonal variation in the abundance, composition and numbers 

 of species was evident at a] 1 subtidal stations. Changes in these 

 community parameters occurred throughout the year at potentially impacted 

 stations (IN, JC, EF) and the reference station (GN) . Yet, the general 

 trend of June and September peaks in density and species numbers remained 

 similar to previous observations. Further, there were no changes in these 

 parameters that were more evident at the potentially impacted stations than 

 at the reference station. Changes in species composition (e.g. increased 

 number of Polydora cnulleryi ) occurred equally among all stations, (except 

 IN) and the significance of this change can only be evaluated by continued 

 monitoring. 



Temporal variations in species composition and abundance have been 

 characteristic of Millstone subtidal communities. Infaunal population 

 fluctuations were generally similar for taxa common to all stations, and 

 changes in the relative abundance of ubiquitous taxa have occurred 

 throughout the year. Although reduced population densities were noted for 

 taxa considered characteristic of a particular station, these reductions 

 were not confined to stations within the influence of plant operation, nor 

 were these taxa totally removed from their respective communities. 

 Seasonal changes, like those observed in the Millstone area, are characteristic 

 of shallow-water benthic assemblages throughout the temperate range 

 (Levings l«175; Maurer et al. 1979; Warwick and Uncles 1980). 



Notable year to year changes in subtidal benthos ficcurred at both the 

 non-impacted station (GN) and the potentially- impacted stations (EF, IN, 

 JC) . These changes were evident in the sedimentary characteristics at the 

 IN and GN stations and additions to the dominant taxa at all subtidal stations. 



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