632 



ANDERSON AND LENAT 



TABLE 3 



ABUNDANCE AND ANALYSIS OF VARIANCE OF MAJOR 

 ZOOPLANKTON SPECIES: EUPHOTIC-ZONE HAULS 



*Explanation of symbols: 

 NS, not significant. 

 S5, significant at the 5% level. 

 Sl, significant at the 1% level. 

 NI, not identified in year 4. 



It, direction of significant change, i.e., decrease or increase. 

 A( ), organism absent in indicated year. 



Power-plant operation may have had a marked positive effect on 

 the average density of Polyarthra through an increase in winter 

 temperatures. In year 4, low densities were recorded during January. 

 By year 6, however, this was the period of maximum density. Since 

 no significant differences were noted between years when all stations 

 were compared, the implication is that power-plant operation did not 

 affect yearly abundances but may have affected its seasonal 

 distribution. 



