Incidence of light and ocean acidification on microbial community, dimethyl sulfide, dimethylsulfoniopropionate and macronutrients in Baffin Bay, Nunavut, Canada

The main objective of this study was to experimentally assess the impact of decreasing pH on the DMS produced by an Arctic phytoplankton seasonal bloom. Furthermore, we investigated how light conditions corresponding to those experienced by a marginal ice phytoplankton bloom and an under-ice or subsurface phytoplankton bloom could modulate the effects of pH on phytoplankton and DMS variations. The latter was motivated by the strong contribution of subsurface phytoplankton layers to annual productivity in several sectors of the Arctic as well as the apparent increasing occurrence of under-ice blooms, attributed to the thinning of sea ice and the replacement of the multiyear ice by first-year ice. This study was funded by the NSERC Discovery Grant Program and Northern Research Supplement Program (M. Levasseur, M. Gosselin), as well as by the NETCARE network (funded under the NSERC Climate Change and Atmospheric Research program), ArcticNet (The Network of Centres of Excellence of Canada), and the Department of Fisheries and Oceans Canada. This is a contribution to the research programs of NETCARE, ArcticNet and Quebec-Ocean.