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The ocean may be storing more carbon than estimated in previous studies

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Our colleague Frédéric Le Moigne contributed to an international study on the efficiency of the oceanic carbon pump. The study, published this week in Nature magazine, reassesses the ocean’s capacity to store carbon, particularly through ‘marine snow’. The CNRS issued a press release about this publication :

The ocean’s capacity to store atmospheric carbon dioxide is almost 20% higher than the estimates presented in the latest IPCC report. These are the findings of a study published in the journal Nature on 6 December 2023 by an international team including a biologist from the CNRS. The scientists looked at the role played by plankton in the natural transport of carbon from the surface to the seabed.

Plankton is fond of this gas, which it transforms into organic tissue through photosynthesis during its development, and some of it is transformed into marine particles at the end of its life. Denser than seawater, this ‘marine snow’ sinks to the seabed, storing carbon and providing essential nutrients for many deep-sea creatures, from tiny bacteria to deep-sea fish.

Based on the study of a database collected from around the world since the 1970s using oceanographic vessels, the team of seven scientists were able to digitally map the fluxes of organic matter throughout the oceans. The resulting new estimate of storage capacity is 15 gigatonnes per year, an increase of around 20% on the previous studies (11 gigatonnes per year) reported by the IPCC in its 2021 report.

This reassessment of the seabed’s storage capacity represents a significant advance in our understanding of carbon exchanges between the atmosphere and the ocean at a global level. While the team stresses that this absorption process takes place over tens of thousands of years, and is therefore not sufficient to offset the exponential increase in CO2 emissions generated by global industrial activity since 1750, this study nevertheless reinforces the importance of the ocean ecosystem as a major player in regulating the global climate in the long term.

Global distribution of organic carbon flux from the surface layer of the open ocean.
© Wang et al., 2023, Nature.

 

Reference:

Biological carbon pump estimate based on multi-decadal hydrographic data. Wei-Lei Wang, Weiwei Fu, Frédéric A. C. Le Moigne, Robert T. Letscher, Yi Liu, Jin-Ming Tang, and François W. Primeau. Nature, le 6 décembre 2023.
DOI : https://doi.org/10.1038/s41586-023-06772-4

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The Warmalis 3 oceanographic campaign!

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Oceanographic Campaign Warmalis 3: Understanding the Functioning of the Pelagic Oceanic Ecosystem and Ultimately Determining its Influence on Tuna Resources in the Western and Central Pacific Region

The WARMALIS 3 campaign, taking place from September 25 to November 8 aboard the R/V ANTEA, aims to better understand the functioning of the pelagic oceanic ecosystem and determine its influence on tuna resources in the western and central Pacific region, which account for more than 50% of global catches. In particular, the campaign studies intermediate trophic levels (zooplankton and micronecton), which constitute the primary food for all large pelagic species in the Pacific. To achieve this, biological data (micronecton trawls, zooplankton nets, EK80 sonars, and acoustic profilers), as well as physical and chemical data, are collected.

 


Example of micronecton capture, with gelatinous organisms, small fish, and shrimp commonly consumed by tuna and other top predators (Photo: V. Allain, SPC-IRD).

 

WARMALIS 3 is the last in a series of three campaigns (2021, 2022, 2023) part of the MICROPAC project (Micronecton in the Pacific, 2021-2023) led by Christophe Menkès (IRD/UMR ENTROPIE) and Valérie Allain (CPS) with partner units: MIO, IMAGO, LEMAR, LOPS, LEGOS, and CLS. After exploring the western and central Pacific from south to north in previous years, the crew is undertaking a 45-day east-to-west traverse along the equator this year.
Four colleagues from LEMAR are on board: Laure Barbin, Jérémie Habasque, Anne Lebourges, and Anaïs Médieu.

 


Campaign plan for Warmalis 3.

 

You can follow the ship’s log on the mission blog.

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PAMPAS project exhibition: Coastal marsh heritage

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The PAMPAS project – Évolution de l’identité PAtrimoniale des Marais des Pertuis charentais en réponse à l’Aléa de Submersion marine, 2019-2023 – is a collaborative research project funded by the French National Research Agency (ANR) and led by the Littoral Environnement et Sociétés de La Rochelle laboratory (LIENSs, CNRS – La Rochelle University). It aims to understand the future of coastal wetlands, focusing on the evolution of the heritage identity of the marshes of the Pertuis Charentais in response to flooding over half a century.
The marshes of Charente-Maritime: a unique study area presenting:

  • A strong heritage identity – landscape, biodiversity, architectural heritage
  • Vulnerability to submersions,
  • Contrasted management methods and a concentration of numerous economic activities – agriculture, shellfish farming, tourism … whose sustainability can be questioned.

In a context of increasing populations and activities in coastal areas, the preservation and maintenance of these socio-ecosystems are essential to safeguard the quality and functions of these constrained environments. The project has expanded the concept of heritage identity to include the ecological and environmental functions of marshes, such as:

  • Their adaptation to the overall rise in sea level through sedimentation,
  • Their role as a buffer against marine submersions limiting the rise in sea level in adjacent areas,
  • Their role in water filtration, nutrient recycling, carbon sequestration, habitat provision, and nursery functions for numerous species.

This project chose to go beyond traditional approaches to the assessment of conservation ecology, economics, and cultural heritage management, all considered insufficient to comprehend heritage as the entirety of components contributing to the collective identity of a marsh.

PAMPAS has:

  • Adopted an interdisciplinary approach applied to three study areas (the marshes of Brouage, Fier d’Ars, and Tasdon), contrasting in terms of natural, cultural, and landscape heritage, as well as management practices: in debate between laissez-faire and embankment, heavily embanked, and reconnected to the sea, respectively.
  • Built a collective approach and participatory engineering, crossing expertise in Humanities and Social Sciences, Life and Earth Sciences, and involving marsh managers, with 48 people from 13 research units and 9 disciplines.

The 3 major objectives of PAMPAS are to:

  • Characterize the natural, cultural, and landscape functions of the marshes and spatially represent these different components of heritage identity;
  • Represent the socio-ecosystem of marshes in terms of functionality, services, resilience, or adaptability to hazards;
  • Define scenarios for the evolution of the heritage identity of the three study sites facing submersion hazards and assess their adaptive potential. These results will be discussed through an interactive mapping tool.

In conclusion, based on a revised definition of heritage identity adapted to marsh areas, PAMPAS provides a new vision for sustainable marsh management by transmitting economic, cultural, and ecological knowledge. The challenges and issues of this project thus far exceed the local level and concern wetlands globally, for which it is now necessary to reconsider analysis and management frameworks, integrating heritage in its various socio-ecosystemic dimensions.

This heritage is not always visible or recognized as such by the entire population. Therefore, this exhibition aims to reveal to the general public not only the results of a research project but also the objects (animals, plants, structures, landscapes, activities, etc.) that could be recognized as full-fledged heritage in the marshes. Showing the invisible, less easily perceived objects, and highlighting the ecological functions of the marshes is the objective of this exhibition.

The exhibition will be visible from September 30 to November 4 at the Ecomuseum of Loix en Ré (Ile de Ré)

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Claire Hellio, awarded the CNRS Innovation Medal

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Congratulations to our colleague Claire HELLIO, who has been awarded the 2023 CNRS Innovation Medal!

Claire, a University Professor at UBO, is in charge of the BIODIMAR platform. The platform is dedicated to biotechnology research, and develops solutions for producing more environmentally-friendly products, mainly from molecules of marine origin.

Extract from the CNRS press release:

Claire Hellio, drawing inspiration from natural molecules for environmentally-friendly products

Claire Hellio develops innovative bioinspired solutions based on active molecules produced by algae and microorganisms. Conducted at the Laboratoire des sciences de l’environnement marin, this work, at the interface between chemistry, biology, biochemistry and ecology, is carried out via the Biodimar bioprospecting platform, which this professor heads up.

Her team responds to the problems and R&D needs of manufacturers, developing specific biotests and innovative biotechnological solutions based on natural substances of marine origin. Applications are mainly in the fields of cosmetics (antioxidants and preservatives) and antifouling coatings (protection of boat hulls against colonization). These solutions are made as environmentally-friendly as possible. This collaboration with companies has, for example, taken the form of a joint laboratory called BiotechALg in partnership with Green Sea, the European leader in microalgae production.

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A look back at the DRASTIC low-carbon oceanographic cruise

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A “low-carbon” oceanographic cruise aboard an old sailing ship off the coast of Norway.

At the Arctic Circle, where the waters of the North Atlantic and the Arctic meet, LEMAR scientists from the European Institute for the Sea in Brest (IUEM) are studying silicon, an essential nutrient for marine micro-organisms such as diatoms and radiolarians. The latter are at the base of the marine food chain. They also play a key role in producing the oxygen we breathe and in sequestering atmospheric carbon.

The project aims to gain a better understanding of marine environmental changes at high latitudes and their consequences for the fate of planktonic siliceous organisms.

Scientists were the first to warn of climate change and now want to show the way to mitigate and reduce carbon emissions. The research was therefore carried out from a sailing boat. The boat’s equipment was also carbon-free: the main winch used to send the scientific equipment to a depth of 1,000 metres was powered solely by human energy, with the scientists transformed into cyclists! This low-tech ‘velotreuil’ proved its effectiveness and gave the scientists a chance to do a bit of sport. Compared with conventional oceanographic vessels, the campaign’s carbon footprint was reduced by 70 tonnes of CO2 (the annual emissions of 11 Norwegians).As the cost of the campaign was also lower, this means that the reduction in carbon emissions saved money. Indeed, the cost of CO2 abatement for the mission is estimated at around €1,000 per tonne. The 20-metre sailing boat was the LUN II, a superb wooden vessel built in Norway (around Alesund) in 1914. It is mainly used as a sailing cargo ship, under the direction of its captain Ulysse Buquen, and has been used to set up laboratories for water filtration and microscopic observations.

The scientific team was intergenerational (ranging from 29 to 58 years old), international (with researchers from Brest, British, and American universities), gender-balanced, and led by women. It consisted of 9 individuals, including several current or former members of LEMAR (links to their profiles): Aude Leynaert, Lucie Cassarino, Matthieu Civel-Mazens, Natalia Llopis-Monferrer, Nicolas Djeghri, Jean Luc Baradat, Oscar Chuberre (photographer), Ulysse Buquen (the captain), and Magnus Brask Nordfonn (sailor).

During their journey, they gave lectures at the universities of Tromsøe, Bodø, and Bergen, and met with Norwegian scientists to promote future collaboration and student exchanges.

The expedition was primarily funded by the French public sector, including the École Universitaire de Recherche Isblue, the ANR (Agence Nationale pour la Recherche), the CNRS, the Brittany region, and the LEMAR laboratory of the IUEM.

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