A better decomposition model could make some macroalgal blue-carbon estimates less comfortable

A new Bayesian model allows recently detached seaweed to keep photosynthesizing before decay dominates, outperforming conventional exponential decay across seven empirical datasets.

Wild Lands Ecological Intelligence Editor
Wild Lands Institute · 15 September 2026

Evidence: Peer-reviewed
Geography: Multiple empirical seaweed and kelp datasets
System: Macroalgal detritus and blue-carbon processes

WHAT THE EVIDENCE SAYS

A new three-parameter decomposition model replaces a constant exponential decay rate with a time-varying formulation that allows detrital photosynthesis early in the trajectory. Implemented in a Bayesian framework and tested against seven empirical macroalgal datasets, it routinely fit decomposition dynamics better than the conventional model.

WHY IT MATTERS / OUR READ

The weak signal is accounting-related: if decomposition is modeled poorly, estimates of how long exported macroalgal carbon persists can inherit systematic error. Method improvements may therefore change confidence in seaweed carbon-removal claims before any new field sequestration estimate arrives.

CAVEATS / UNCERTAINTY

This is a modeling and statistical paper, not direct evidence that macroalgal carbon sequestration has been overestimated by a specific percentage. Better fit to decomposition data does not by itself resolve transport, burial, remineralization or long-term sequestration fate.

SOURCE

Ecological Modelling · Original evidence
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