Plankton as a Source of Food

Abstract

WHILST it is correct to say that on occasions concentrations of algæ in eutrophic lakes and reservoirs will be very high, it should be remembered that these peaks of production are of short duration. Again, of the dry weight of the diatom Fragilaria crotonensis, estimated at 110 tons, quoted by Walker¹, approximately one half is silicon. Further, the fine mesh of any netting that would be necessary to retain algæ would add enormously to the difficulties of collection. I am, therefore, doubtful whether attempts to use phytoplankton as food would be practical or economic, and, in my view, it would be better to investigate the possibilities of large–scale collection of marine zooplankton, as advocated by Hardy².