Frontiers of instability in marine ecosystems and carbon export (Marine Frontiers)

Marine Frontiers is an innovative project that will push the frontiers of knowledge on the limits to stability in marine ecosystem functioning. It will introduce, for the first time in a global model, three triggers of widespread mortality: viruses, early life cycles, and microplastic pollution, and test the impact of extreme conditions that are plausible for the coming Century.

Marine ecosystems keep the concentration of atmospheric CO2 about 200 parts per million (ppm) lower than it would be otherwise. Marine ecosystems were not stable in the geological past. They contributed and possibly triggered massive Ocean Anoxic Events. Global marine ecosystem models used for climate study have been shown to underestimate variability in a range of variables, including variability in carbon and oxygen fluxes over multiple time and space scales, and variability in plankton biomass. The incapacity of the current generation of ocean carbon models to reproduce observed variability means instabilities in marine ecosystems and associated carbon fluxes have never been adequately explored.

Mortality processes are critical in the ocean because the biomass turns over very quickly. Yet mortality processes have received little attention so far. Recent advances in observation technology (particularly genomics and automated imaging) and in knowledge have highlighted processes that could radically alter mortality processes in the ocean. Marine Frontiers will attempt, for the first time, to model three of the most important triggers of mortality, in order to explore the stability of marine ecosystems in a changing environment.

Marine Frontiers will expand mortality processes in the NEMO-PlankTOM model using theory, observations, and new computing methods. A new framework for representing marine ecosystems is proposed through the representation of Particle Functional Types (PtclFTs) that include living particles such as phytoplankton, zooplankton, and bacteria, as well as dead particles...