Response of bacterioplankton community structure to an artificial gradient of pCO2 in the Arctic Ocean

[摘要] In order to test the influences of ocean acidification on the ocean pelagicecosystem, so far the largest CO₂ manipulation mesocosm study (EuropeanProject on Ocean Acidification, EPOCA) was performed in Kings Bay(Kongsfjorden), Spitsbergen. During a 30 day incubation, bacterial diversitywas investigated using DNA fingerprinting and clone library analysis ofbacterioplankton samples. Terminal restriction fragment length polymorphism(T-RFLP) analysis of the PCR amplicons of the 16S rRNA genes revealed thatgeneral bacterial diversity, taxonomic richness and community structure wereinfluenced by the variation of productivity during the time of incubation, butnot the degree of ocean acidification. A BIOENV analysis suggested a complexcontrol of bacterial community structure by various biological and chemicalenvironmental parameters. The maximum apparent diversity of bacterioplankton(i.e., the number of T-RFs) in high and low pCO₂ treatments differedsignificantly. A negative relationship between the relative abundance ofBacteroidetes and pCO₂ levels was observed for samples at theend of the experiment by the combination of T-RFLP and clone libraryanalysis. Our study suggests that ocean acidification affects the developmentof bacterial assemblages and potentially impacts the ecological function ofthe bacterioplankton in the marine ecosystem.

[学科分类] 地球化学与岩石