Kelp forests have attracted growing interest as a potential nature-based climate solution, but key scientific questions remain unresolved. How much carbon reaches long-term storage? Where does it end up? And how confidently can it be measured and attributed? This article explains how the Kelp Forest Foundation contributes to answering these questions through collaborative research, transparent methods, and standards-oriented science.
In previous articles, we explored why kelp carbon matters and how it works. The science is advancing quickly, but it is still in its early days. We know kelp forests can store significant amounts of organic carbon under the right conditions, and that a fraction of this carbon can be exported for carbon sequestration stored for the long term, but the exact proportions, pathways, and permanence are still being uncovered.
This article zooms in on what the Kelp Forest Foundation (KFF) is doing to help fill those gaps. Over the past four years, KFF has been part of four major projects, each addressing a different piece of the kelp carbon puzzle. From modelling and field measurements to finance and cutting-edge molecular tools, these projects are building the foundations of a toolkit for kelp carbon science.
In our earlier articles on kelp carbon, we highlighted the challenges around how hard it is to tracking kelp carbon once it leaves the forest. Detritus can drift for kilometres, can fragment or dissolve into the water as dissolved organic carbon (DOC), or sink into the deeper waters sea, each pathway with very different consequences for how long that carbon remains stored. This dispersal uncertainty is a key reason kelp has been slower to enter blue carbon frameworks compared to ecosystems where carbon accumulates directly in the soil beneath the plants.
To tackle this, in 2021, KFF partnered with the University of Cambridge to develop OceanBioME, a new coupled physical–biogeochemical model that simulates how particulate and dissolved carbon move through currents, where they might settle, and how much could end up in long-term storage pools. Models are vital for this kind of research because many processes involved in carbon export and burial happen over areas and timeperiods vast spatial and temporal scales that too large to observe through field studies alone cannot capture. They allow scientists to test scenarios, such as how offshore kelp farms might influence air–sea CO2 exchange, or which coastal regions are most likely to retain kelp detritus that would otherwise be impossible to observe directly.
What makes OceanBioME different from older models is how flexible and easy to use it is. It’s built in a modern programming language called Julia, which means it runs fast even on ordinary computers rather than needing powerful supercomputers. It also links directly to Oceananigans.jl. The model is designed like a set of building blocks, so researchers can add or change specific biological or chemical processes; like how kelp takes up nutrients, how it photosynthesises, or how carbon reacts in seawater, without having to rebuild the whole thing from scratch. Importantly, OceanBioME.jl can also represent “biologically active particles”: small pieces of kelp or organic matter that drift with the currents and interact with the water around them. This feature is crucial for kelp carbon research. It lets scientists test what happens after kelp grows and breaks off, for example, how far the pieces travel, whether they sink deep enough to store carbon for the long term, or if they decompose and release it back into the water. It can also help point to areas where kelp pieces are likely to end up, so that targeted field measurements can be done
The Cambridge model has been published as a peer-reviewed, open-source tool (Strong-Wright et al., 2023), setting a new standard for transparency and collaboration in kelp carbon research. By bridging biological processes, physical transport, and chemical transformation in one system, it provides a far more realistic way to simulate the fate of kelp-derived carbon in a changing ocean.
In recognised blue carbon ecosystems such as mangroves, seagrasses, and salt marshes, carbon burial in sediments is currently considered the most permanent storage pathway. These plants trap carbon-rich material beneath their roots, locking it away for centuries. Kelp, however, behaves differently. It grows on rocky reefs without soil beneath its canopy, so carbon burial only occurs when fragments break off and are carried away to “depocentres”: low-energy areas like sheltered seabeds, continental slopes, or deep-sea canyons where material can settle and remain undisturbed. Carbon stored in the deep ocean persist even longer than in coastal sediments, but it is still uncertain how much kelp carbon actually reaches those depths.
To investigate whether this burial pathway operates in kelp systems, KFF collaborated with the University of Namibia and the King Abdullah University of Science and Technology (KAUST) on a multi-year PhD project focused on offshore Namibia, where the Kelp Blue pilot farm provides a new source of biomass. Rather than collecting new material, the study analysed existing sediment cores originally collected by the University of Bremen and stored at ETH Zurich, using established blue carbon techniques such as sediment coring, isotope tracing analysis, carbon dating, biomarkers, and environmental DNA (eDNA)DNA. These methods were used to determine how old the carbon in those sediments is, and how quickly it accumulates , and the source of the organic carbon – all essential steps for establishing a baseline for kelp carbon burial.
The Cambridge model was also used to predict where detritus is most likely to settle based on ocean currents, helping to test whether the identified depocentres are indeed the sites where organic carbon ends up. This approach provided valuable insight into how well model predictions match real-world data.
While this project was more of a baseline assessment than a full burial study, it represents an important first step in understanding kelp’s potential for long-term carbon storage. It also allows future assessment also marks the first attempt to assess of carbon burial in the context of offshore kelp farming, which may prove particularly important since offshore sites are often closer to deep-sea canyons and slopes where carbon could remain stored for centuries or longer. By applying tried-and-tested blue carbon methods in this new context, the project helps bridge the gap between established sediment science and the emerging field of kelp carbon research.
For kelp to play a role in climate markets, the science needs to be translated into accepted standards that define what counts as real, measurable, and permanent carbon removal. This is where questions of permanence and attribution, the two most debated issues in kelp carbon, come into focus. How long does kelp-derived carbon stay locked away? And can we prove that it originated from kelp drawing down atmospheric CO₂ rather than other sources in the ocean? What are accepted ways of measuring the carbon pathways?
To address this, KFF is developing a Gold Standard methodology for quantifying carbon sequestration from kelp cultivation, restoration, and conservationafforestation. Creating such a framework is essential but challenging: kelp carbon moves through complex pathways, from growth and detachment to transport and eventual burial, and each stage affects how much carbon is ultimately stored. A robust methodology must account for these processes while remaining flexible enough to apply across different sites, species, monitoring budgets and project types, rather than being tailored to one caselocation.
The first methodology draft was submitted to Gold Standard in early 2024, and is currently under revision, representing a milestone: kelp carbon, for the first time, is being assessed against the same criteria used for other natural climate solutions. Like Japan’s J-Blue Credit system, which set up an independent certification body and market platform, the aim is to create credibility and transparency in a field where uncertainty has been a barrier. But unlike the domestic Japanese scheme, this work is designed to provide an internationally applicable framework.
One of the hardest challenges in kelp carbon science is proving where the carbon came from once it’s buried or transported offshore. Traditional methods like stable isotopes or lipid markers can show organic matter in sediments, but they often cannot tell whether it originated from kelp or from other marine plants and plankton. This makes it difficult to establish attribution, a crucial step if kelp carbon is ever to be counted in carbon markets.
To overcome this, KFF is part of a research project led by working with the Cawthron Institute and Sequench in New Zealand to develop environmental DNA (eDNA) tools that can trace kelp carbon back to its source. Every organism leaves behind fragments of DNA in its environment, and these can be detected in water and sediment samples. By building a library of genetic “fingerprints” for giant kelp (Macrocystis pyrifera), the project is creating assays that can pick out kelp DNA even from tiny traces mixed within sediments.
The ability to identify kelp-derived carbon with this level of precision would be transformative. It would allow researchers to track how far fragments travel, confirm whether they are reaching deep-sea burial sites, and quantify the contribution of kelp to long-term carbon stores. Unlike older techniques, eDNA can be scaled to hundreds of samples at once, is non-invasive, and offers unprecedented sensitivity.
The development of eDNA biomarkers makes it possible to approach kelp carbon with a level of precision that hasn’t been possible before. Instead of inferring origins indirectly, researchers can now detect kelp DNA itself in sediment samples, even far from the forest where it was produced. That means burial and transport pathways, which until now were mostly modelled or assumed, can be tested directly. Bringing this kind of molecular evidence into blue carbon science can allow us to confirm that long-term storage does come from kelp, putting attribution on much firmer ground.
Together, these four projects are form a toolkit for kelp carbon science. Oceanographic models now allow us to predict the fate of exported carbon in ways fieldwork alone cannot. Field studies are beginning to establish sedimentary baselines, giving us direct evidence of whether kelp contributes to long-term storage. Methodologies for carbon accounting are being developed and tested against the standards required for international markets. And new molecular tools are emerging that can identify kelp’s fingerprints in sediments, offering clarity where older techniques fell short. Kelp carbon research is still at an early stage, but these projects provide the essential foundations for establishing its role. With robust models, field measurements, accounting frameworks, and molecular tools now in development, kelp is beginning to be evaluated on the same terms as other blue carbon ecosystems in climate policy and markets.
Unlocking the power of kelp