Influence of Oxygen Concentration on Photosynthesis in Marine Plants

Abstract

Photosynthesis was studied in various atmospheres of oxygen with marine plants grown on the Great Barrier Reef near Lizard Island, Australia. Inhibition of photosynthesis in a 100 % oxygen atmosphere ranged from 12 to 83 % in specific marine plants when compared to a nitrogen or helium atmosphere. The rates of photosynthesis in these marine plants were in general similar to those of terrestrial plants which fix CO₂ via the reductive pentose phosphate cycle. We conclude that photo-respiration is present in specific marine plants at levels similar to those found in terrestrial plants with the reductive pentose phosphate cycle.