. Discovery reports. Discovery (Ship); Scientific expeditions. i84 DISCOVERY REPORTS increasing plankton yield in Table XIII. The correlation between poor plankton (plant and animal) and poor phosphate, and rich plankton and rich phosphate presumably illustrates the restrictive law of population.^ Table XIII. Correlation between volume of plankton and concentration of phosphate Locality Plankton mean volume per station Phosphate Phytoplankton Zooplankton Concentration Breadth of zone miles Guanape Islands Lobos Islands Cape Carranza San Juan Antofagasta Caldera Pichidanque Bay <25
. Discovery reports. Discovery (Ship); Scientific expeditions. i84 DISCOVERY REPORTS increasing plankton yield in Table XIII. The correlation between poor plankton (plant and animal) and poor phosphate, and rich plankton and rich phosphate presumably illustrates the restrictive law of population.^ Table XIII. Correlation between volume of plankton and concentration of phosphate Locality Plankton mean volume per station Phosphate Phytoplankton Zooplankton Concentration Breadth of zone miles Guanape Islands Lobos Islands Cape Carranza San Juan Antofagasta Caldera Pichidanque Bay <25 8o mg., Medium = 40-80 mg., Poor= <40 mg. P2O5 per cubic metre. In reviewing the phosphate concentrations on these lines, no reference has yet been made to the minor irregularities such as occur off Cape Carranza, Antofagasta and San Juan, where patches of phosphate reduced to a medium value may be met at or near the surface layers in the midst of higher concentrations; nor to the fact that rich as may be the phosphates at the surface in the upwelling region they are usually less rich than those in lower layers. The possibility of relating this reduction to the activity of phyto- plankton may now be considered. Off Cape Carranza two patches of dense phytoplankton were met: one was situated at 5-15 miles from the coast, the other offshore from 35 to 85 miles, and neither at first sight shows a direct relation to the amount of phosphate in the surface layer and to the patch of medium phosphate illustrated in Fig. 54. We may endeavour, however, to measure the reduction of surface phosphates by comparing these values with those in deeper water, say at 100 m. In this comparison the mean of the values at o and 20 m. may be expressed as a percentage of the mean of the values ^ The low values of phytoplankton off the Guanape Islands and the Lobos Islands may be due to over-cropping of the animal plankton, here in its highest z 2D0- SGUNDING IN METRES_ 5861 3031 I7G6
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectscientificexpedition
