Kaleigh Harrison
Coastal wetlands are often highlighted for their role in carbon sequestration and flood protection, but recent research suggests the tools we use to measure their performance may be oversimplifying the science. A new study led by researchers from the University of Rhode Island and University of North Florida has found that a significant portion of the organic matter measured in marsh sediments may not actually contribute to either long-term carbon storage or marsh elevation gain.
The core issue? Standard blue carbon accounting methods often treat all organic material in sediment samples as if it has the same impact on carbon storage and marsh stability. But according to the researchers, some organic matter—especially material dissolved in sediment porewater or bound within mineral structures—has negligible volume and does not help marshes build up elevation over time.
This gap in measurement practice matters because marsh elevation directly affects wetland survival as sea levels rise. If elevation is overestimated, the projected resilience of these ecosystems—and the climate mitigation projects built around them—may not match reality. That has downstream implications for restoration project planning, credit valuations in carbon markets, and climate adaptation investments.
Impacts on Carbon Markets, Project Risk, and Coastal Infrastructure
For sectors involved in carbon finance, coastal engineering, and environmental risk analytics, these findings point to a need for more precise carbon modeling. Overestimating carbon storage not only skews the performance of blue carbon credits but can also undermine the credibility of climate claims made by project developers or investors.
Models used in wetland restoration, offset crediting, and risk forecasting often rely on assumptions that now appear incomplete. If dissolved or non-volume-contributing organic matter is included in sediment data without correction, projections of marsh resilience and storage capacity may be inflated. The study suggests incorporating correction factors that differentiate between organic matter that adds to sediment structure and that which doesn’t.
This nuance could drive the next generation of verification protocols, monitoring technologies, and restoration strategies. It also opens new ground for service providers in consulting, measurement tech, and regulatory compliance to deliver more accurate, science-aligned solutions.
Rather than discard past datasets, the researchers advocate recalibrating them with updated methods—a path forward that balances scientific integrity with continuity for ongoing projects. Their cross-disciplinary approach, involving geologists, ecologists, and modelers, offers a scalable model for refining blue carbon science without starting from scratch.