Growth and mortality studies of Ascophyllum nodosum, a perennial brown alga sensitive to water 

 temperature change, were included in the rocky intertidal sampling program. Tip length analyses helped 

 distinguish between a stressed population at Fox Island and populations at two reference stations. Since 

 1979, Ascophyllum plant loss averaged about 60% and tip loss about 80% overall; there was much 

 variability in plant and tip mortality from year to year. 



With the exception of the FE intertidal community, no significant changes to the benthic shore 

 biota were observed that could be attributed to MNPS operation. 



BENTHIC INFAUNA 



Infaunal communities in the vicinity of MNPS were sampled to provide data needed to characterize 

 suhtidal and intertidal community abundance and species composition, identify spatial and temporal 

 changes in these parameters and evaluate whether any observed changes were the result of construction 

 and/or operation of MNPS. 



Intertidal 



Sediments at the three intertidal sampling stations were composed of medium sands that usually 

 contained low amounts ( < 3%) of silt/clay. During the baseline period, sediment grain size and the 

 percentage of silt/clay were more consistent at stations exposed to constant wave-induced scour while 

 at the seasonally protected .Jordan Cove beach, these parameters exhibited considerable variability. 



At all stations, infaunal communities were dominated by polychaetes and oligochaetes; these groups 

 often accounted for over 75% of the total number of individuals collected annually. The polychaetes, 

 Scolecokpides viridis, and Polydora ligni, and the oligochaetc group were among the dominants at all 

 stations. At .Jordan Cove, oligochaetes accounted for over 60% of all individuals in 5 of the past 6 

 years and was the most abundant taxon in each of the last six sampling years. At Giants Neck and 

 White Point, rhynchocoels, Paraonis fulgens, and Haploscoloplos fragilis were dominant, contributing 

 over 10 percent of the total individuals over years. 



