On the Ratio of Nitrogen to Phosphorus in the Sea

Data are presented confirming the belief of Harvey and of Redfield that, in broad outline, the ratio of nitrate-nitrogen and of phosphate-phosphorus in the sea and of nitrogen and phosphorus in marine plankton lies within fairly narrow limits. The ratio approaches twenty to one when expressed in terms of milligram-atoms or nine to one by weight. There are however deviations from this broad generalization, but they do not provide a reason for discarding the concept but rather suggest close examination of the causes of the variations.