their subsequent analysis are being undertaken by the Scripps Oceano- 

 graphic Institution in cooperation with the Fish and Wildlife Service. 

 Acvjessory experimental work on rates of biological processes in the 

 survey area is also under way at that Institution, 



Analysis 



Compute total numbers of each stage, - With reliable quantitative 

 collections of eggs and larvae at each station, it is further necessary 

 to integrate the total numbers over both time and spaceo The time ele- 

 ment involves proper weighting to account for the time interval between 

 successive observations over the station pattern. This in turn involves 

 certain assumptions, or preferably a determination of a curve of the 

 volume of spawning as a time function. The integration over space de- 

 pends upon a curve of distribution of the organisms in the sea area 

 sampled. Both phases of integration are still in the developmental 

 stageso An additional element in the computation is an adjustment 

 necessitated by the smaller catches of larvae by day than by nighto 



For the time being, work will be directed toward determining total 

 n'ombers of each stage in the particular area included within the egg 

 and larval survey. This covers only a part of the spawning region. 

 Extension to other areas must await either better boat facilities or 

 a fortunate discovery of relationships with meteorological conditions 

 which may provide a certain reliability in extrapolation. 



In any even, the integration must be proceeded or followed by 

 certain adjustments. 



Adjust for drift, - Since the survey area is of limited extent and 

 contiguous to other possible areas of spawning, some allowance must be 

 made for gains in numbers by organisms drifting into the area and losses 

 from their drifting out. This aspect is not serious with respect to eggs, 

 which hatch iii three days and^ therefore, cannot drift farj but it is 

 important in the case of larvae which may spend weeks or even months in 

 the drifting phase© With the pattern of circulation determined from 

 hydrographic observations, an allowance should be feasible. The prin- 

 cipal difficulty now foreseen is the amount or rate of lateral diffusion, 

 which would not be apparent from the circulation pattern alone. This 

 adjustment is therefore still in the problem stage. 



Adjust for rate of developmento - The numbers of eggs or larvae found 

 in each stage will vary inversely with the time occupied in passing through 

 the stage. One occupying a short interval of time will afford a smaller 

 accumulation of individuals than one occupying a longer period. Adjusting 

 nianbers to allow for the '^accumulation effect" involves knowledge of the 

 rate of development or of growth. This has already been worked out for 

 the eggs, but the rate of growth of larvae has yet to be determined, 



28 



