Cape Elizabeth 



N. 



~i — I — I — I — I — I — I — I 1 — I — r 



69° 68° 



42 



67° W. 



Figure 1. — Zooplankton sampling stations. Gulf of Maine coastal waters, 1965 and 1966. 

 Station numbers are shown in parentheses. 



Figure 2. — Mean seasonal volumes of zooplankton by Gulf 

 of Maine coastal areas in 1965 and 1966. 



decreased in the spring, whereas in 1966 

 they increased from a low in winter to an 

 annual high in spring. Volumes decreased 

 from summer to fall in both years. These 

 values are considered as minimal estimates 

 of zooplankton abundance because sampling 

 was done only in daylight in the upper 20 m. 

 of water, and the netting had relatively 



large apertures (used to obtain the 

 larger zooplankton, particularly calanoid 

 copepods ). 



Volumes at each sampling location were 

 examined for differen"es among the areas 

 with the Kruskal-Wallis analysis of variance 

 (Siegel, 1956). Differences in station values 

 among the areas were significant (P<0,05) 

 in spring, sunnmer, and fall. Volumes gen- 

 erally decreased from west to east; the notable 

 exception was in the high volumes in the 

 central area in the spring of 1966. In winter, 

 volumes were higher in 1965 than in 1966, 

 but differences annong the areas in both years 

 were not statistically significant (table 1). 



Annual trends in zooplankton abundance 

 along the coast were similar in 1965 and 

 1966; mean annual volumes for each of the 

 areas declined from a high in the west to a 

 low in the east (fig. 3). Differences in vol- 

 umes between years and between areas were 

 tested with the Mann- Whitney U test (Siegel, 

 1956). Volumes were significantly higher in the 

 west than in the east (P< 0.001). Volumes in 

 the central area were between the western and 

 eastern extremes. Between-year volumes in 

 the central and eastern area were similar, 

 but in the west were about four tinnes greater 

 in 1965 than in 1966 (P< 0.01), 



