Plankton in an acidifying ocean : from individual responses to community changes and the potential of adaptation

Ocean acidification has strong direct (decreased seawater pH) and indirect (altered food regimes) effects on the performance of marine organisms, their trophic interactions and, consequently, whole ecosystems. Therefore, the aim of this thesis was to investigate potential direct and indirect effects of elevated pCO2 on marine planktonic organisms and their community composition, with a main emphasise on copepods and their adaptational potential. The development of high throughput sequencing technologies has provided scientists with an efficient tool to assess the biodiversity of marine communities, particularly with the recent advances in community barcoding technologies using universal primers. Another aim of this thesis was therefore, to test whether community barcoding is suitable for the assessment of marine planktonic communities, and allows the detection of compositional changes, which would probably remain unnoticed using classical morphological approaches.