BLACKBURN and NELLEN: EGGS AND LARVAE IN AN UPWELLING AREA 



Table 1. -Means of variables for the water column at stations from long. 17°08' to 17°25'W, in series of stations 

 along lat. 21°40'N together with indications of relative abundance of adult sardines explained in Discussion. 



'Three stations for eggs and zooplankton. 



^Estimated from settled volumes at 1 ml = 0.8 g. Not corrected for phytoplankton contamination. 

 sQne station for chlorophyll. 

 ■•Two stations for eggs and zooplankton. 



sEstimated according to mean ratio of small to total zooplankton at same longitudes in other series, namely 

 67%. Not corrected for phytoplankton contamination. 

 'Unknown. 

 Two stations for chlorophyll. 



SARDINE EGGS/m2 



ANCHOVY EGGS/m2 







ZOOPLANKTON I00-500>i g/m2 

 a B B 



ZOOPLANKTON >500^ g/m2 



1 



CHLOROPHYLL mg/m2 



1000 



800 



600 



400 



200 







200 







50 







100 



50 



SARDINE EGGS/m2 



W I7''40' 



Figure 3.— Distribution of sardine eggs, anchovy eggs, and 

 environmental parameters along lat. 21°40'N on 22-23 April 1974 

 (series 9 in Table 1). 



00000 



ANCHOVY EGGS /m2 



00 



ZOOPLANKTON 100-500^ 

 ^^"' _ -   i 



_ilu 



J_r 



ZOOPLANKTON >500^ g/m2 



CHLOROPHYLL mg/m2 



- 50 



1000 

 800 

 600 



400 

 200 

 

 200 



-100 



-50 

 



300 

 200 

 100 

 

 Om 



100 

 200 



W I7''40' 



I7''30' 



I7»20 



I?"!©' 



i7'00' 



Figure 4.-Distribution of sardine eggs, anchovy eggs, and 

 environmental parameters along lat. 21°40'N on 9-10 May 1974 

 (series 10 in Table 1). 



of nonzero wire angles on distance covered by the 

 net. To determine effects of clogging, the expected 

 flow of water through the net was compared with 

 that indicated by the flowmeter revolutions. 

 Counts of various kinds of fish eggs and larvae 

 from each haul were standardized in numbers 

 under 1 m^ of sea surface. 



In general the spatial distribution of zooplank- 

 ton biomass was similar for the 100- to 200- and 

 200- to 500-]um fractions. The two fractions of 

 larger-sized plankton were also distributed 

 similarly, but not like the smaller-sized fractions. 

 Thus we distinguish only zooplankton at 100 to 

 500 jLim and at >500 nm (Figures 2-4). Most of the 



887 



