Annual Variation of Planktonic Vegetation, 1933

Publisher Website
Google Scholar
Abstract
Vertical hauls were made with a very fine silk net having a meter attached, which measured the volume of water filtered, at positions off Plymouth throughout the year 1933.The quantity of phytoplankton was assessed from its content of yellowgreen colouring matter, and expressed in terms of “units of plant pigments” per cubic metre of water filtered.The diatom population per cubic metre at Station L4 on March 28th was estimated to contain phosphorus amounting to 2 mg. P2O5, whereas dissolved phosphate amounting to some 15 mg. P2O5 had been used from each cubic metre of water by the diatoms during the previous six weeks.It is concluded that the production of phytoplankton during this period greatly exceeded the quantity found at the height of the spring outburst, and that the excess had been eaten by the herbivorous zooplankton.