A large amount of carbon is stored as dissolved organic matter (DOM) in the ocean, and remains stable for thousands of years. This stability is astonishing, given that heterotrophic bacteria in the deep ocean are often carbon-limited. The stability is of global relevance, as the mobilization of this carbon pool would most likely alter the carbon cycle and climate. One hypothesis for the long-term stability of DOM in the ocean is the dilution hypothesis, stating that the huge diversity of different DOM molecules and, accordingly, the low concentration of individual compounds, limits bacterial growth. We develop a biogeochemical model based on these principles of neutral uptake, simulate networks of microbial-DOM interactions and assess emerging spatial and temporal patterns.

Funding: Ministry for Science and Culture (MWK), State of Lower Saxony

List of people involved:

Sinikka Lennartz
Thorsten Dittmar

Collaborators at ICBM:

Bernd Blasius
Christoph Feenders

External Collaborators:

Andreas Oschlies (GEOMAR)
David Keller (GEOMAR)