FISHERY' BULLETIN: VOL. 69, NO. 3 



virtually all organisms as small as 200/li in length 

 (O'Connell and Leong, 1963) or lOO/x in diameter 

 (Leong, 1967). The upper, size limit was less 

 easily defined, but organisms as long as 14 mm 

 were delivered at the filtering apparatus, though 

 the large individuals were often mutilated. 



Five cruises were carried out, three in Sep- 

 tember to November 1961 and two in the same 

 period of 1962. For each cruise a pattern of 

 18 sampling blocks was selected from a possible 

 281 that covered an area of almost 6,000 square 

 miles (Figure 1). To insure reasonably good 

 coverage of the entire area, the ])opulation of 



blocks was divided into three approximately 

 equal subareas and a set of six blocks was se- 

 lected at random from each. The blocks were 

 occupied by the shortest practical track from 

 northwest to southeast. Each cruise pattern 

 required about 2.5 days of vessel time. 



Each sampling block was 51.8 km- (20 square 

 miles) in area, the only exceptions being some 

 of the blocks adjacent to the coast or to islands. 

 Nine 1.6-km (1-mile) samples were collected at 

 each block in a continuous series along two con- 

 necting sides (Figure 1, insert) and were pre- 

 served in Formalin for laboratory processing. 



^ 



PT DUME 



UN DIEGO 



34° 



33° 



119* 



118° 



117° 



Figure 1. — The sampling area and entire population of .sampling blocks;. Six blocks were randomly selected from 

 each of the three subareas for each cruise and occupied by the shortest route from north to south. Sampling 

 blocks are 4X5 miles and the insert shows the manner of transect sampling. Four of the nine samples from 

 each block were .selected randomly for organism enumeration. 



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