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

CLAUDE BELZILE, SERGE DEMERS, GUSTAVO A. FERREYRA, IRENE SCHLOSS, CHRISTIAN NOZAIS, KARINE LACOSTE, BEHZAD MOSTAJIR, SUZANNE ROY, MICHEL GOSSELIN, EMILIEN PELLETIER, SÔNIA M. F. GIANESELLA AND MARIA VERNET

PHOTOCHEMISTRY AND PHOTOBIOLOGY

Año: 2006 p. 850 - 856

0031-8655

Ultraviolet (UV) irradiance has a broad range of effects on marine 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 on mesocosm studies shows that although a UV increase even well above natural intensities often has subtle effects on bulk biomass (carbon, chlorophyll), it can significantly impact the food-web structure due to different sensibility to UV among planktonic organisms. Given the complexity of UV impacts evidenced by mesocosms studies, interactions of UV with current environmental changes (eutrophication, climate change) are likely to have significant effects on the functioning of marine ecosystems.