Plankton production off Plymouth and the mouth of the English Channel in 1939

Abstract

A quantitative seasonal survey of the phytoplankton and small zooplankton has been made from the end of January to the end of August 1939, at a station, L₄, with supplementary observations at a station off Rame Head, both near Plymouth. The results are compared with those of a fuller survey made in 1934.The spring maximum in numbers of plant cells was late, not being reached until the middle of April.The monthly means of the total numbers of animals caught were of the same order in the two years, but the numbers of copepods plus copepodites in 1939 were only two-thirds of those in 1934.