UV Effects on Marine Planktonic Food-Webs: A Synthesis of Results from Mesocosm Studies

BELZILE. C., S. DEMERS, G. A. FERREYRA, I. SCHLOSS, C. NOZAIS, K. LACOSTE, B. MOSTAJIR, S. ROY, M. GOSSELIN, E. PELLETIER, S. M. F. GIANESELLA AND M. VERNET

PHOTOCHEMISTRY AND PHOTOBIOLOGY

American Society for Photobiology

Año: 2006 vol. 82 p. 850 - 856

0031-8655

planktonic organisms. Direct and indirect effects on individual organisms have complex impacts on food-web structure and dynamics, with implications for carbon and nutrient cycling. Mesocosm experiments are well suited for the study of such complex interrelationships. Mesocosms offer the possibility to conduct well-controlled experiments with intact planktonic communities in physical, chemical and light conditions mimicking those of the natural environment. In allowing the manipulation of UV intensities and light spectral composition, the experimental mesocosm approach has proven to be especially useful in assessing the impacts at the community level. This review of mesocosm studies shows that, although a UV increase even well above natural intensities often has subtle effects on bulk biomass (carbon and chlorophyll), it can significantly impact the food-web structure because of different sensitivity to UV among planktonic organisms. Given the complexity of UV impacts, as evidenced by results of mesocosm studies, interactions between UV and changing environmental conditions (e.g. eutrophication and climate change) are likely to have significant effects on the function of marine ecosystems.e.g. eutrophication and climate change) are likely to have significant effects on the function of marine ecosystems.