Pubblicazione scientifica

Simulated ocean acidification reveals winners and losers in coastal phytoplankton

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità

RIASSUNTO

The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA). OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3) for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm) in five of them while the other five served as controls (380 μatm). We found: (1) Bulk chlorophyll a concentration and 10 out of 16 investigated phytoplankton groups were significantly and mostly positively affected by elevated CO2 concentrations. However, CO2 effects on abundance or biomass were generally subtle and present only during certain succession stages. (2) Some of the CO2-affected phytoplankton groups seemed to respond directly to altered carbonate chemistry (e.g. diatoms) while others (e.g. Synechococcus) were more likely to be indirectly affected through CO2 sensitive competitors or grazers. (3) Picoeukaryotic phytoplankton (0.2–2 μm) showed the clearest and relatively strong positive CO2 responses during several succession stages. We attribute this not only to a CO2 fertilization of their photosynthetic apparatus but also to an increased nutrient competitiveness under acidified (i.e. low pH) conditions. The stimulating influence of high CO2/low pH on picoeukaryote abundance observed in this experiment is strikingly consistent with results from previous studies, suggesting that picoeukaryotes are among the winners in a future ocean.

DATA

Data di pubblicazione: 30/11/2017

AUTORI

BACH LENNART T
ALVAREZ-FERNANDEZ SANTIAGO
HORNICK THOMAS
STUHR ANNEGRET
RIEBESELL ULF

ENTE DI AFFERENZA

GEOMAR HELMHOLTZ CTR OCEAN RSCH KIEL KIEL GERMANY
ALFRED WEGENER INST HELMHOLTZ ZTR POLAR & MEERESFORSCHUNG BIOLOGISCHE ANSTALT HELGOLAND HELGOLAND GERMANY
LEIBNIZ INST FRESHWATER ECOLOGY & INLAND FISHERIES IGB EXPERIMENTAL LIMNOLOGY STECHLIN GERMANY
UNIV CONNECTICUT US

RIVISTA

PLoS ONE, 12(11), e0188198

IMPACT FACTOR

2,870

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