The Standing Crop and Primary Productivity of the Phytoplankton of Abbot's Pond, North Somerset

The investigations of Moss (1967a, 1969a, b, c), Happey (1968, 1970a, b, c, d) and Hickman (1970) showed that, owing to its location in a sheltered tree-lined valley, Abbot's Pond, north Somerset, exhibited thermal and chemical stratification. The phytoplankton was found to be fitted for existence in the short but stable water column (Moss 1969b), whilst the species were characteristic of the eutrophic diatom and chlorococcalean plankton associations (Moss & Abdel Karim 1969; Happey 1968; Hickman 1970) as defined by Hutchinson (1967). The phytoplankton standing crops, as measured by chlorophyll a content and cell counts, have been shown to be large with annual mean values on an areal basis 4-13-4 times greater than those of the epipelon (Moss 1969c). The present paper continues the phytoplankton standing crop measurements in detail, together with measurements of the primary production over a 24-month period to determine the primary production by the phytoplankton.