MEAN NUMBER OF TAXA PER TIME INTERVAL 



20- 



< 



5 



5- 



o f 



0030 0230 0500 0600 



1200 

 TIME 



1830 1930 2030 2300 



Figure 2. --The mean number of taxa captured during the various time intervals 

 (days combined) is plotted. Vertical bars represent 95% confidence intervals. 

 Units of time along the x axis are unequal. 



total of 73 taxa were 

 and 27 taxa was the m 

 shows the pattern for 

 for the 2 days pooled 

 tests) between the 2 

 0600, when significan 

 pooled, there were si 

 taxa in samples colle 

 1930; in addition, si 

 0500 and 0600, 1930 a 

 were captured during 

 intermediate numbers 



identified from th 

 aximum found in a s 



the mean number of 

 The only signifi 

 days in the number 

 tly fewer were capt 

 gnificant increases 

 cted at 0030 vs. 02 

 gnificant decreases 

 nd 2030, and 2030 a 

 the day, the most d 

 during the rest of 



ese samples. Many were rarely encountered, 

 ingle sample (July 17, 1982). Figure 2 



taxa captured during each time interval 

 cant differences (p < 0.05, MWU , ST 

 of taxa captured occurred at 0030 and 

 ured on July 16. When the days were 



(p < 0.05; MWU, ST tests) in number of 

 30 and in those collected at 1830 vs. 



in number of taxa were observed between 

 nd 2300. In general , the fewest taxa 

 uring the first hour after sunset, and 

 the night. 



The mean and standard deviation for the abundance of the more common taxa 

 are presented for the different time intervals in table 3. The cyclopoid 

 copepod Oithona colcarva (Bowman) was the most abundant of the organisms captured 

 at all time intervals except those between 1200-2030, although there was some 

 variation in this pattern when the days were considered separately (fig. 1). 

 During the morning interval (0600-1200), 0. colcarva , forami ni fera , and certain 

 calanoid and harpacticoid species were the most abundant organisms; however, 

 all occurred in relatively low numbers. In the afternoon (1200-1830), foraminifera 



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