Organic matter turnover by pelagic microorganisms under the impact of ocean acidification


Contact
sendres [ at ] geomar.de

Abstract

Marine bacteria are the main consumers of the organic matter and largely control <sub>2</sub> and CO<sub>2</sub> budgets in the ocean. The present increase in anthropogenic O<sub>2</sub> emissions is constantly decreasing seawater pH. This ocean acidification is expected to affect enzymatic hydrolysis of organic compounds with so-far unknown consequences for microbial physiology, organic matter cycling and marine biogeochemistry. We studied the effect of ocean acidification on a natural plankton community during a large-scale mesocosm study in the Raunefjord (Norway). We determined the concentration and composition of dissolved organic matter, in particular combined carbohydrates and amino acid, as well as marine gel particles, bacterial growth and enzymatic rates of organic matter hydrolysis. Dissolved organic carbon concentrations were increasing over time in all treatments while dissolved organic nitrogen concentrations remained stable. We observed higher protein hydrolysis rates, gel particle concentrations, and bacterial cell numbers in the low pH treatments. We conclude that ocean acidification may favor bacterial growth and degradation activities and therewith potentially change organic matter composition and cycling in the future ocean.



Item Type
Conference (Talk)
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Not peer-reviewed
Publication Status
Published
Event Details
ASLO Aquatic Science Meeting, New Orleans, USA.
Eprint ID
33365
Cite as
Endres, S. , Flerus, R. , Galgani, L. , Roa, J. and Engel, A. (2013): Organic matter turnover by pelagic microorganisms under the impact of ocean acidification , ASLO Aquatic Science Meeting, New Orleans, USA .


Share

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item