densities (Newell and Newe] 1 1973). These observations suggest a very 

 short cyprid stage for B^. improvisus . Over all years, the abundance of 

 barnacle nauplii and cyprids was lowest from 1976 - 78 ( Fig. 13 and 

 15). 



Barnacle nauplii, were found in greater abundances at NB while the 

 cyprids were more abundant at F.N where a more suitable substrate was 

 available, particularly for the intertidal species B^. balanoides . Both 

 nauplii and cyprids were found in significantly greater abundances 

 during the night at NB (Table 4). There were no significant day-night 

 differences at EN. 



G astropoda 



The gastropod taxa found in MNPS zooplankton consisted of the egg 

 and veliger stages of local epibenthic species of snails. Gastropods 

 have contributed between 1.5-3.6% (NB) and 3.3-9.1% (EN) to the 

 zooplankton collected at MNPS since 1976 and in 1983 2.6% and 5.A% at NB 

 and EN respectively (Table 3) . 



Regression analysis on data from this taxon produced low R^ values 

 (<0.3), probably due to lumping of many species into the broad taxon 

 Gastropoda. A large proportion of eggs and veligors collected were 

 representatives of Littorina littorea , the adults of which are 

 ubiquitious on intertidal rocky shore zones around MNPS (NUSCo 1983). 



Gastropod eggs were most abundant from winter through summer and 

 lowest in the fall. Veligers were most abundant during the late spring 

 and summer. Eggs were more abundant at EN, consistent with the areas of 

 greatest adult abundance. Significantly higher abundances of veligers 

 were found during the night sampling periods, suggesting nocturnal 

 migrations into the water column (Table 4) . 



Decapoda 



The Decapoda contain the largest crustaceans and exhibit a 

 diversity of form and habitat (Yonge 1949). Between 1% (EN, 1977 and 

 1983) and 3% (EN, 1982) of the zooplankton collected at MNPS were larval 

 decapods (Table 3) . 



14 



