t(i I lie MNI'S z()<ii)l.mkton since I97f), .iiul bL-twoen "i?, (KN) nnd 87. (NB) in 

 1983 (Tables 1, and 2). Similar to C. Iiamatus , lowest P^. minut us 

 abundances were observed in 1976 and 1982 (Fig. 9) . Temora longicornis 

 was most common in winter and spring zooplankton collections at MNPS 

 (Fig. 10) and contributed between 8-14% (EN) and 12-28% (NB) to MNPS 

 zooplankton collections in the 1976 to 1982 period and A% (EN) and 11% 

 (NB) in 1983 (Tables 1 and 2). The lowest abundance was observed in 

 1976 (Fig. 11). The offshore predominance of IP. minutus was indicated 

 by a significant difference (see t-test results in Table 4). 



Cirripedla 



The cirripedia consisted of the early life stages (nauplii, 

 cyprlds) of several species of barnacles, including Balanus balanoides , 

 B^. crenatus , B^. improvisus and B^. cburneus . Nauplii are the earliest 

 larval stages and provide a distribution phase while the later 

 developing cyprids are the settling stage. Since 1976, nauplii and 

 cyprids were found seasonally in MNPS zooplankton and accounted for 0.6 

 to 9% at NB and 0.9 to 5.5% at EN (Table 3). 



Each year, barnacle nauplii were found in the zooplankton during 

 two time periods (Fig. 12). In winter (January through March), the 

 nauplii were those of the ubiquitous B. balanoides , the adults of which 

 are an obvious constituent of New England rocky intertidal zones. In 

 summer (July and August), nauplii consisted primarily of B^. improvisus 

 (a common subtidal form) but nauplii of B^. crenatus and B^. eburneus were 

 also found. Similar winter and summer broods have been described for the 

 southern North Sea (Newell and Newell 1973). 



Barnacle cyprid abundances were lower than nauplii densities and 

 did not exhibit the bimodal seasonal cycle. The barnacle cyprids 

 described by our model primarily consisted of B^. balanoides (Fig. 14). 

 As indicated previously, nauplii of B^. improvisus were present but in 

 such low numbers compared to B. balanoides , that the subsequent cyprid 

 stages were not represented by a separate peak on our model. Highest 

 settlement densities of B^. i mprovisus cyprids at the MNPS intake 

 Exposure Panels have been detected during August (NUSCo 1982b) . This is 

 the same period in which B^. improvisus nauplii were found in greatest 



12 



