at Fox Island-Exposed and the low abundance of Chondrus in the low 

 intertidal at Fox Island-Sheltered. Bay Point, Zone II, is not closely 

 associated with the other Zone II stations because of the high mussel 

 coverage and scarcity of Fucus plants at this site. 



When the same data are analyzed by month (Figure 5) , three distinct 

 clusters are apparent at the 67 percent level, corresponding to seasonal 

 groupings. Cluster A represents a late spring-early summer flora, 

 roughly April - June. Cluster B is winter-early spring (December - 

 March) , and Cluster C is late summer-autumn (July - November) . 



As mentioned in the section on qualitative algal collections, the 

 thermal effluent has an effect on the seasonal occurrence and reproductive 

 phenology of the algae growing in the quarry. If this effect were to 

 extend to one or more of the intertidal stations, it would decrease this 

 station's (or stations') similarity, relative to the control stations 

 and to previous years. An advantage of the present quantitative sampling 

 methods, particularly the representation of percent similarity in the 

 form of clustering dendrograms, is the ease with which we could detect 

 such a change; the affected collection would no longer be included in 

 the appropriate spatial or temporal group. 



To summarize the results of the Rocky Shore Program, the intertidal 

 communities in the Millstone Point area show considerable variability 

 between and within themselves. However, these fluctuations may occur on 

 a seasonal basis, or with degree or exposure to waves and tides; they 

 could be attributed to natural cycles as well as to man- induced impact. 



Characterization of these cycles, particularly of abundance of the 

 perennial macroalgae ( Chondrus , Fucus , Ascophyllum ) and barnacles, is a 

 major goal of the monitoring program. Because of their important role 



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