fall (fig. 8). These differences were related 

 to variations in abundance of the dominant 

 species. During summer 1964, C. finmarchicus 

 and P. minutus showed large ( >500/ lOOm.3) 

 mean seasonal increases in abundance over 

 the previous summer (fig. 5). In contrast, the 



decline in copepod abundance in the fall of 

 1964 was caused by the sharp decrease in mean 

 seasonal nunnbers of C. typicus (ca. 6,000/ 

 100m. 3) and to a lesser degree by reductions 

 in nunnbers of P. minutus and M^ lucens (ca. 

 300/l00m.3). 



8- 



7- 



6 



|5 

 o 



•4- 



WEST 



CENTRAL 



EAST 



Figure 6. — Mean annual zooplankton volumes by Gulf of 

 Maine coastal areas for 1963 (broken line) and 1964 

 (solid Une). Mann-Whltney U and Z values are given 

 for between-area comparisons. 



WINTER SPRING SUMMER FALL 



Figure 8. — Seasonal curves of copepod abundance. Gulf of 

 Maine coastal waters, 1963-64. 



Figure 7. — Mean seasonal zooplankton volumes by Gulf of Maine coastal areas in 1963 and 1964. Mann- Whitney between- 



year U values and probabilities are given by season. 



