Project Activities
Understanding Ocean Nitrogen Cycling is Critical for Climate Predictions
Nitrogen cycling in the ocean plays a critical role in regulating marine life, carbon storage, and Earth’s climate. When biologically easily available nitrogen is lost from the ocean, biological productivity declines, reducing the ocean’s ability to absorb and store carbon dioxide from the atmosphere. These nitrogen losses also influence emissions of nitrous oxide, a powerful greenhouse gas. Because microbial processes control whether nitrogen is recycled or lost, understanding how these processes respond to changing environmental conditions is essential for predicting the future of ocean ecosystems and climate regulation.
As climate change and human activity continue to reduce oxygen levels in the ocean, low-oxygen zones are expanding and intensifying. Despite their small size, these regions account for a large share of global nitrogen loss, yet current climate models cannot reliably predict their impact. This uncertainty limits our ability to forecast future ocean productivity, greenhouse gas emissions, and climate feedbacks. By revealing how microbes control nitrogen transformations in oxygen-depleted waters, RECLESS provides the knowledge needed to improve climate models and better anticipate how ongoing ocean deoxygenation will shape the Earth system.
Our Objectives
How does nitrogen cycling in oxygen minimum zones work?
We will transform the current understanding of N cycling across globally representative O2-depleted systems through innovative approaches, including the introduction of O2-contamination-free in situ incubations as a new gold standard in the field, quantification of O2 ventilation at high spatial and temporal resolution with oceanic gliders, lowering the detection limit for O2 by an order of magnitude, and iteratively using models to synthesise and analyse the biogeochemical and oceanographic results.
Why does it work this way?
We will perform cutting-edge experimental and biomolecular analyses to elucidate the mechanisms underlying the microbial N transformations and how they respond to environmental controls, thus quantifying the key parameters required for predictive modelling of microbial N cycling in a “universal” formulation applicable across all types of O2-depleted systems.
How will oxygen depleted waters develop?
In an iterative, synergistic process we will configure and parameterize a novel ecosystem model with explicit, first-principles representation of N-transforming microbial populations, and incorporate it into ocean models that resolve the small-scale circulation of O2-depleted systems. This will for the first time allow robust prediction of the changes in and interactions between O2 depletion and biogeochemical N and C cycling in future climate scenarios.
Field Locations
*Data from Copernicus Global Ocean Biogeochemistry Hindcast https://doi.org/10.48670/moi-00019 and Breitburg et al 2018, Science.
