sontliwestorl y nnci nor l.liwester] y winds. Sediments at those stations are 

 unifortnily composed of medium s;ind with low organic content and both 

 infaunal communities are dominanted by species that are less dependent on 

 fine organic material as food and more adapted to a constantly shifting 

 sand environment. 



The differences observed in 1983 between the potentially impacted JC 

 community and other monitoring communities are consistent with observations 

 made in previous years at Millstone (NUSCo 1982, 1983). These differences 

 (between JC and CN/WP) , and the similarity between GN and W communities 

 are most likely related to the natural environmental conditions that exist 

 in the Millstone area and not to any physical or chemical changes resulting 

 from power plant operation. 



Temporal Differences at potentially impacted vs non- impacted stations. 



In 1983, all monitoring stations exhibited seasonal changes in animal 

 populations typical of temperate intertidal assemblages (Sanders 1968; 

 Green 1969; Holland and Polgar 1976; Whitlatch 1977). At all stations, the 

 numbers of species and animal abundances wore generally higher in summer 

 and fall and lower in winter and early spring. Intertidal communities were 

 primarily dominated by few species, and as with other infaunal communities 

 of low diversity, seasonal patterns of these organisms strongly influenced 

 the pattern of the community (Holland and Polgar 1976; Zajac and Whitlatch 

 1982). Many species exhibited periods of peak abundance in September, 

 following the favorable environmental conditions of summer. 



Seasonal changes in abundances, species composition and the 

 sedimentary environment in 1983 were considerably more pronounced at the 

 potentially impacted station (JC) than at either the other potentially 

 impacted station (WP) or the reference station (GN) . This larger seasonal 

 variability at JC has been characteristic of this station throughout the 

 monitoring program and appears to be related to natural seasonal changes in 

 intensity of the wave-induced scour and not to plant- induced physical 

 changes. Temporal patterns observed in the communities inhabiting the 

 other potentially impacted station (WP) were similar to those at the 

 reference station (GN) ; this is consistent with past observations. 



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