FISHERIES BULLETIN: VOL. 84, NO. 1 



shore As with E. pacifica, both sexes of AT. difficilis 

 were found in significantly greater numbers in the 

 north (Table 3). The abundance of N. difficilis was 

 not correlated with surface chlorophyll a (Table 4). 



Euphausiid Laminarinase Activity 



Similar to the results of Willason (1983) and Willa- 

 son and Cox (in press), males of both euphausiid 

 species showed significantly less LA than females 

 (P < 0.01, both cases, Wilcoxon test). Males in this 

 study had about 70% (Euphausia pacifica) or 80% 

 (Nematoscelis difficilis) of the LA of females (Table 

 3). To simplify the presentation of the data on the 



contour maps, LA values of males and females at 

 each station were averaged. 



The values of LA for Euphausia pacifica within 

 the sampling grid ranged from 50 to 430. Euphau- 

 siids with the lowest LA values were found in off- 

 shore areas and in the nearshore area along the cen- 

 tral coast. Euphausia pacifica with the highest levels 

 of LA were found just south of San Francisco Bay 

 and adjacent to the south of Point Conception (Fig. 

 6). These areas overlapped with and extended just 

 south of the regions of highest surface chlorophyll 

 a. There was a positive correlation between LA of 

 E. pacifica and chlorophyll a over the entire grid 

 (Table 4). 



Table 4— Correlations between chlorophyll a, zooplankton abundance, and laminarinase activity (LA) for 

 Euphausia pacifica, Nematocelis difficilis, and Calanus pacificus. For euphausiids, abundance and LA values 

 used in the analyses are the averages of males and females. Numbers in parentheses refer to the number 

 of samples used in regression analyses. 



'Correlation coefficients which were not significant at the 95% level. 



J L 



Euphausia pacifica 



Laminarinase 

 Activity 



>300 



200-300 



100-199 



< 100 



None Captured 



///.Point Conception 



San 

 rv/; ;; . Diego 



J L 



j i 



38 c 



36° 



34 c 



32 e 



Figure 6— Euphausia pacifica laminari- 

 nase activity (LA). Expressed as fig 

 glucose per gram wet weight per 

 minute 



124< 



122 c 



120 c 



118 c 



164 



