Publication Date:
2015-02-27
Description:
- There is increasing evidence that different light intensities strongly modulate the effects of
ocean acidification (OA) on marine phytoplankton. The aim of the present study was to investigate
interactive effects of OA and dynamic light, mimicking natural mixing regimes.
- The Antarctic diatom Chaetoceros debilis was grown under two pCO2 (390 and
1000 latm) and light conditions (constant and dynamic), the latter yielding the same integrated
irradiance over the day. To characterize interactive effects between treatments,
growth, elemental composition, primary production and photophysiology were investigated.
- Dynamic light reduced growth and strongly altered the effects of OA on primary production,
being unaffected by elevated pCO2 under constant light, yet significantly reduced under
dynamic light. Interactive effects between OA and light were also observed for Chl production
and particulate organic carbon quotas.
- Response patterns can be explained by changes in the cellular energetic balance. While the
energy transfer efficiency from photochemistry to biomass production (Φe,C) was not affected
by OA under constant light, it was drastically reduced under dynamic light. Contrasting
responses under different light conditions need to be considered when making predictions
regarding a more stratified and acidified future ocean.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
,
info:eu-repo/semantics/article
Format:
application/pdf
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