Effects of light intensity on photosynthesis and dark respiration in six species of marine phytoplankton

✍ Scribed by P. G. Falkowski; T. G. Owens

• Publisher: Springer-Verlag
• Year: 1978
• Tongue: English
• Weight: 629 KB
• Volume: 45
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00391815

✦ Synopsis

Using an oxygen polarographic electrode, the shapes of photosynthetic curves and the effects of light on dark respiration in 6 species of marine phytoplankton wer examined. The species used were Skeletonema costatum, Ditylum brightwellii, Cyclotella nana (ghalassiosira pseudonana) (all Bacillariophyceae), Dunaliella tertiolecta (Chlorophyceae), Isochrysis galbana (Haptophyceae), and Gonyaulax tamarensis (Dinophyceae). A hysteresis was observed in all species examined with respect to increasing and decreasing light. Compensation light intensities varied by over 4 orders of magnitude, suggesting that the I% light depth is an ambiguous measure of the euphotic zone. The data suggest that dark respiration accounts for ca. 25% of gross photosynthesis, but is species-dependent. In addition, respiration versus cell size does not describe an inverse exponential function over the size scales examined.