Example of determining phytoplankton production
=Let us use field observations on the nutrition of the Calanus helgolandicus(CLAUS) population of the Blaek Sea bathyplankton, obtained in June 1959, as an example for determining the value for phytoplankton production with respect to rhythm and rate of grazing(PETnPA, 1964).
=During the first 10 days of June, the phytoplankton standing stock did not vary significantly. In the morning and at night(at the beginning and end of the day) the average phytoplankton standing stock had practically equal values. The rate of phytoplankton mortality changed in proportion to the standing stock. The Calanus helgolandicus population during this period consisted mainly of the old copepodite stages that regularly ascend to the upper water layer(12 to 25 m) for feeding. In all other water layers, food con sumption during the periods of ascent and descent insignificant. Calanus helgolandicus consumes almost all phytoplankton species, but primarily Noctiluca, as well as various Peridinea and Diatomea. The cell division rates of all mass food species was obtained under corresponding conditions in the laboratory and in bottles placed in the sea at the time of the work