A Comparative Study on Photosynthesis Temperature Relationships and Their Seasonal Changes in Marine Benthic Algae

In each of the species examined — 4 Chlorophyceae, 7 Phaeophyceae and 4 Rhodophyceae — the optimum temperature for photosynthesis was apparently higher in summer material than in winter material. In the brown algae the optimum temperature for the apparent photosynthesis lies between 20°C and 23°C, in the green algae and in most of the red algae between 25° and 30°C. In most of the red algae the activity decreased markedly at 35°GC, while a considerable part of the green algae survived at this temperature. In 50% of the species of brown algae examined the photosynthetic activity decreased at 30°C and was completely lost at 35°C, while in the remaining species a strong resistance to high temperatures was observed.