ENVIRONMENTAL CONTROL OF PHOTOSYNTHESIS IN THE SEA

Abstract

A theoretical equation for the photosynthesis‐light relation is developed which includes the effects of inhibition in intense light. Assuming 1) that phytoplankton adapts to seasonal light changes and 2) that nutrient deficiency affects the carbon:chlorophyll ratio of natural phytoplankton populations, equations arc derived which determine photosynthesis per unit chlorophyll and the carbon: chlorophyll ratio as functions of incident radiation and nutrient concentration. These equations appear to describe the main trends in the open North Sea and in a sea loch on the west of Scotland. The photosynthesis‐chlorophyll relation also describes the main trends of observations in the Sargasso. For a very shallow turbid area, the agreement was not so good.