Photosynthetic and photoprotective characteristics of ice algae, sinking algae and under-ice phytoplankton during spring

Light is an important factor to determine the beginning of the algal development. Important variations of light conditions are observed in the sea-ice environment during spring period, from important snow pack conditions (low light) to the formation of meltponds (high light). Sea ice microalgae possess high photosynthetic plasticity to acclimate, which may depend of their niche habitats. In our previous study within the Canadian Arctic Archipelago, we hypothetized that under-ice blooms composed of different algal communities (phytoplanktonic centric diatoms vs sympagic pennate diatoms) exhibit different light sensibility. The main objective of this study is to investigate photoprotection and photoinhibition by bottom ice algae in response to relatively high irradiances and compare photosynthetic properties between ice algae, sinking algae and underlying phytoplankton. In situ experiments of ice algae with different light treatments will be realized during the entire sampling period, while photosynthetic parameters will be assess with a Pulse-Amplitude Modulation (PAM) and P vs E curves (Takuvik collaboration).

Fieldwork site: Qikiqtarjuaq, eastern Baffin Island, Nunavut, Canada

PI: S. Rysgaard

Project lead: V. Galindo (CEOS)

Project participants: Virginie Galindo (CEOS), Soren Rysgaard (CEOS)

Fieldwork Summary/Photo blog: Link to project summary report