As we continue our march through the climate crisis, the word carbon is on everyone’s lips – there’s too much in the atmosphere and not enough in the ground, and its causing the world to heat up. But how is it all connected?
Carbon is the building block of all life on earth, it’s found in every living being, every meal we eat, and even in the air that sustains us. On our planet, carbon circulates between land, ocean and the atmosphere through processes known collectively as the carbon cycle. Most of it is stored within rocks and sediments, buried and compressed over millions of years to form coal, oil and gas. Living systems, like rainforests, peat bogs and coastal ecosystems also capture vast amounts of carbon in plants, soils, and sediments. These reservoirs (or sinks) are like deep freezer storage, preventing all our carbon from returning to the earth’s atmosphere at once, and ensuring that our climate remains stable. The release of this carbon into the atmosphere through fossil fuel consumption is a well-known driver of our present climate crisis.
Incredibly, marine processes make up about 83% of the global cycle, and carbon captured and stored in this environment even has its own special name: blue carbon. Vegetated ecosystems (such as mangroves, tidal marshes, sea grasses and macroalgae) sequester and store huge quantities of blue carbon, in both the plants and the sediment below. To get an idea of the scale, although coastal habitats make up about 2% of our ocean area, they account for over 50% of sediment carbon in ocean sediments, and store around 33 billion tonnes of carbon in total [1]. Pelagic marine species also play important roles in transporting carbon into deep sea storage, from the vertical migrations of mesopelagic fish between the surface and deep waters, to the sinking remains of the fish themselves (known as deadfall carbon) slowly making their way to the ocean’s gloomy depths [2].
Vegetated ecosystems like mangrove forests play a vital role in blue carbon sequestration
Fishing for trouble
Many of these processes rely on healthy marine ecosystems, therefore threats such as unsustainable fisheries, coastal development, pollution and climate change can impact blue carbon storage. Vegetated blue carbon ecosystems are incredibly threatened – it is estimated that up to 67% of the historical global mangrove range, 35% of tidal salt marshes, and 29% of seagrasses have been lost [1]. Moreover, the destruction or degradation of these habitats causes them – in a rather ironic twist – to emit the carbon they have stored for centuries into the atmosphere and oceans, causing them to become sources of greenhouse gases. Experts say that as much as 1.02 billion tons of carbon dioxide are being released annually from degraded coastal ecosystems, that’s equivalent to 11.3 million transatlantic flights on a Boeing 747![1, 3].
Another significant driver of blue carbon release is due to the physical disruption of the seafloor by destructive activities like bottom trawling. By resuspending marine sediment, previously buried carbon is exposed to potential microbial degradation and enters the carbon cycle all over again. A recent study found that up to 50% of the carbon released in this way ends up in our atmosphere within a decade, with the remaining dissolved carbon resulting in increased ocean acidification [4].
A sustainable future starts now
Whilst the issue of habitat loss and over-exploitation won’t be solved overnight, we can take immediate steps to better monitor our blue carbon stores. Where traditional marine monitoring practices like net-based fishing and bottom trawling result in the physical disruption of marine sediments and the removal of local fauna and habitats, modern, non-invasive technologies provide a way to observe and monitor ecosystems safely from afar. In recent decades, tools such as autonomous underwater vehicles, aerial surveys, and satellite remote sensing have transformed how we observe and understand the ocean.
At Fjordstrong, we specialise in a truly “zero-impact” approach to marine monitoring. Our video-based data solutions capture high-quality biodiversity information without disturbing the seabed, making them ideal for sensitive living habitats such as oyster reefs and vegetative blue carbon systems. Paired with Geographic Information Systems (GIS) and predictive modelling, we can map these environments in detail, anticipate threats, and equip our clients with the insights they need to protect blue carbon resources and pursue sustainable marine development. Whether its government Marine Protected Area monitoring or offshore scour protections, our portfolio proves that marine monitoring can be both robust and zero-impact, supporting clients to make informed decisions for sustainable blue development without compromising biodiversity.
These efforts are critical because the ocean, as the world’s largest carbon sink, represents a powerful natural solution to climate change. Effective management and restoration of blue carbon habitats could prevent hundreds of millions of metric tons of CO₂ from entering the atmosphere each year, while conserving marine biodiversity supports additional carbon sequestration by maintaining essential ecosystem functions. By combining proven zero-impact monitoring with restoration and protection efforts, we can take meaningful steps toward a healthier ocean, where thriving blue carbon ecosystems contribute to a balanced and resilient climate for generations to come.
Whether its equipment supply, data analysis, or full cycle surveys, get in touch today to find out more.
Featured image: Photo by Benjamin L. Jones on Unsplash
[1] Howard et al., 2014. Coastal Blue Carbon: Methods for assessing carbon stocks and emissions factors in mangroves, tidal salt marshes, and seagrass meadows. https://www.unep.org/resources/publication/coastal-blue-carbon-methods-assessing-carbon-stocks-and-emissions-factors
[2] Lutz, et al., 2018. Oceanic Blue Carbon (Flyer) https://www.grida.no/publications/416
[3] The Blue Carbon Initiative. About Blue Carbon. https://www.thebluecarboninitiative.org/about-blue-carbon
[4] Atwood et al., 2024. Atmospheric CO2 emissions and ocean acidification from bottom-trawling. Frontiers in Marine Science. https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1125137/full
[5] Macreadie et al., 2021. Blue carbon as a natural climate solution. Nature Reviews Earth & Environment. https://repository.kaust.edu.sa/server/api/core/bitstreams/0c411cb3-6b8e-46ab-8996-8987e721b9b2/content
