EVALUATION OF THE EXPOSURE PANEL PROGRAM, 1979-1981 



Sources of variability 



At least five potential sources of variability have influenced the 

 data collected during this program. Station location, substrate type, 

 and placement of panels on the racks can be standardized. Seasonal 

 cycles in reproduction and dispersal of organisms and year to year 

 changes in the dominance of species can only be assessed through repetitive 

 sampling. 



Station location . Five stations have been sampled during the last 

 three years (Fig. 2). Giants Neck is beyond the influences of the 

 thermal effluent and is considered a reference station. Effluent is in 

 the undiluted effluent of MNPS where the greatest thermal impacts are 

 observed. The other three stations are located in the waters surrounding 

 Millstone Point. 



Community structure and abundance of individuals at White Point, 

 Fox Island, and Intake have been compared to those at Giants Neck and 

 Effluent for the last three years (NUSCo 1982). Giants Neck, White 

 Point, and Fox Island have had consistently high interstation similarities, 

 which were attributed to their locations at docks. Intake has been the 

 least similar to the other ambient water stations; a factor attributed 

 to its exposed location and deployment near the surface in deep water. 

 Effluent communities have consistently been least similar to the other 

 four (Fig. 3). These trends in similarities between stations are 

 important because a change in the similarity of a community from one 

 most similar to those at Giants Neck to one more similar to those at 

 Effluent would suggest power plant impacts. 



