Whitehead, R. F.. University of Quebec at Rimouski, mowhirob@uqar.uquebec.ca
de Mora, S. F.. University of Quebec at Rimouski, stephen_demora@uqar.uquebec.ca
Demers, S. University of Quebec at Rimouski, serge_demers@uqar.uquebec.ca
Lean, D. University of Ottawa, dlean@science.uottawa.ca
Gosselin, M. University of Quebec at Rimouski, michel_gosselin@uqar.uquebec.ca
Mostajir, B. University of Quebec at Rimouski, behzad_mostajir@uqar.uquebec.ca
Mostajir, . INRS-Oceanologie, University of Quebec at Rimouski, behzad_mostajir@uqar.uquebec.ca

The anthropogenic-related destruction of stratospheric ozone and the subsequent increase in UV-B radiation impacting aquatic ecosystems has stimulated research into the effects of sunlight, in general, and UV-B, in particular, on marine carbon cycling. Numerous studies have shown that UV-B can have a detrimental effect on marine primary production and microorganisms, but the effects can be highly variable depending on species and light regimes. UV-B has also been established as a crucial driving force in marine photochemistry especially for photochemical reactions involved in the transformation of dissolved organic material (DOM). A variety of approaches have been tried in order to simulate the marine ecosystems and the light fields to which they are exposed. However, for the most part, studies on the photobiological and photochemical effects of UV-B have been conducted separately. Here we will present data from a mesocosm study where complete assemblages of planktonic organisms (<200 microns) from the St. Lawrence estuary were exposed to natural and artificially UV-B enhanced radiation over a ten day period. The focus of this presentation will be changes in the inorganic carbonate and dissolved organic carbon systems and their relationships to biological parameters.
Day: Wednesday, Feb. 3
Time: Poster
Location: Sweeney Center
Code: CS65WE1480S