Table 13. --Comparison of the Integrated rate of primary production in the isothermal layer and 

 water column to a depth of 100 m. obtained in situ and with the laboratory incubator, 1961 



^ Isothermal layer: r^ = 0.90, p< 0.01 



U = 170; p > 0.20 (two-sided test) 



^ Water column: 



r^ = 0.82, p < 0.01 



U = 148; p > 0.20 (two-sided test) 



than 0.20 for a 2-sided test; this result in- 

 dicates that the transformed rates have es- 

 sentially the same distribution as the in situ 

 rates. A similar result (table 13) was obtained 

 with the water column values and a conversion 

 factor of 9.2 to convert laboratory incubator 

 rates into situ estimates (U = 148; p > 0.20-- 

 2-sided test). 



Although this result may seem somewhat 

 surprising, a closer examination of the data 

 shows that any prediction of in situ production 

 (water column or isothermal layer) based on 

 laboratory incubator measurements would have 

 a relatively large potential error of estimate. 

 Indeed, this poor predictability is what one 

 would expect. The samples in the laboratory 

 incubator are exposed to constant light flux 

 of a color and intensity different from the 

 natural flux field at the respective in situ 



depths. Furthermore, at the intensities used in 

 the incubator, deep samples may experience 

 saturation and perhaps inhibition effects that 

 could further complicate the relation between 

 in situ and laboratory incubator rates. These 

 latter effects may explain the somewhat higher 

 degree of correlation obtained between the 

 isothermal layer data than between the water 

 columin data. 



The correlation between the results from the 

 different incubation techniques probably is not 

 a chance event, and the scatter in the relation 

 may reflect the difference in response of the 

 plants to the different conditions of the two 

 techniques. 



Because of the inherent incompatibility of the 

 trailing bottle and in situ incubation methods 

 as practiced on our cruises, it is impossible 

 to compare them closely. Trailing bottle and 



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