SECT. 4J 



GEOGRAPHIC VARIATIONS IN PRODUCTIVITY 



363 



The cycles of production on the Fladen Ground are shown in Fig. 8 and 

 Table II. Note that no winter values (November-March) are given. There is 

 the tacit assumption that winter production is negligible, since the total for 

 the rest of the year is referred to as "annual production". However, the lack of 

 winter data appears to have been due mainly to the occurrence of horizontal 

 advection, a complication which renders Steele's method impractical. 



■J 



Apr MayJun. Jul Aug Sep Oct 

 Apr. MayJun Jul Aug Sep Oct 



1951 10- 

 5- 



r^iy^l 



Apr. MayJun Jul Aug Sep Oct 



1952 5 - 



Apr MayJun Jul. Aug Sep Oct 



1.00 

 0.75 

 0.50 

 0.25 



Apr. MayJun. Jul. Aug. Sep. Oct. Nov. 



I0|- 



1953 5- 

 — 



^rwA^Jl/^lAi 



Apr. May Jua Jul. Aug.Sep.Oct. Nov. 



Fig. 8. Primary production in g carbon/m 2 /day (A) and wind strength (m/sec) (B) on (lie- 

 Fladen Ground. (After Steele, 195G.) 



Table II 

 Primary Production on the Fladen Ground (g carbon/m 2 ). (After Steele, 1956.) 



The advantage of estimating production from phosphate utilization, on the 

 other hand, lies in the fact that the process is thereby integrated over relatively 

 long periods of time (the intervals between sampling). This eliminates errors 

 inherent in attempting to describe annual cycles on the basis of a series of 

 scattered, short-term photosynthesis measurements which may be highly 



