Plant Nutrients in the Sea

Abstract

Two difficulties have been raised by critics of the suggestion that, for the benefit of the fisheries, large-scale addition of plant nutrients to selected parts of the sea may be considered in the future¹. The first difficulty concerns the quantities of nutrients required; Michael Graham describes these as "mountainous, nay astronomical"², and Dr. W. R. G. Atkins, on surer grounds, estimates the annual turnover of phosphorus in the phytoplankton of the English Channel at about one ton for each square kilometre of surface. The quantity is neither astronomical nor even discouraging.