Seafloor primary production in a changing Arctic Ocean

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2024
Auteurs (20) : ATTARD Karl SINGH Rakesh,kumar GATTUSO Jean-pierre FILBEE-DEXTER Karen KRAUSE-JENSEN Dorte KÜHL Michael SEJR Mikael ARCHAMBAULT Philippe BABIN Marcel BÉLANGER Simon BERG Peter GLUD Ronnie,n HANCKE K JÄNICKE Stefan QIN Jing RYSGAARD Soren SØRENSEN Esben,b TACHON Foucaut WENZHÖFER Frank ARDYNA Mathieu
Revue scientifique : Proceedings of the National Academy of Sciences nexus
Volume : 121
Fascicule : 11
Pages :
DOI : 10.1073/pnas.2303366121
URL : https://doi.org/10.1073/pnas.2303366121
Abstract : Phytoplankton and sea ice algae are traditionally considered to be the main primary producers in the Arctic Ocean. In this Perspective, we explore the importance of benthic primary producers (BPPs) encompassing microalgae, macroalgae, and seagrasses, which represent a poorly quantified source of Arctic marine primary production. Despite scarce observations, models predict that BPPs are widespread, colonizing ~3 million km2 of the extensive Arctic coastal and shelf seas. Using a synthesis of published data and a novel model, we estimate that BPPs currently contribute ~77 Tg C y?1 of primary production to the Arctic, equivalent to ~20 to 35% of annual phytoplankton production. Macroalgae contribute ~43 Tg C y?1, seagrasses contribute ~23 Tg C y?1, and microalgae-dominated shelf habitats contribute ~11 to 16 Tg C y?1. Since 2003, the Arctic seafloor area exposed to sunlight has increased by ~47,000 km2 y?1, expanding the realm of BPPs in a warming Arctic. Increased macrophyte abundance and productivity is expected along Arctic coastlines with continued ocean warming and sea ice loss. However, microalgal benthic primary production has increased in only a few shelf regions despite substantial sea ice loss over the past 20 y, as higher solar irradiance in the ice-free ocean is counterbalanced by reduced water transparency. This suggests complex impacts of climate change on Arctic light availability and marine primary production. Despite significant knowledge gaps on Arctic BPPs, their widespread presence and obvious contribution to coastal and shelf ecosystem production call for further investigation and for their inclusion in Arctic ecosystem models and carbon budgets.
Mots-clés : -
Commentaire : doi: 10.1073/pnas.2303366121
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Citation :
Attard K, Singh RK, Gattuso J-P, Filbee-Dexter K, Krause-Jensen D, Kühl M, Sejr M, Archambault P, Babin M, Bélanger S, Berg P, Glud RN, Hancke K, Jänicke S, Qin J, Rysgaard S, Sørensen EB, Tachon F, Wenzhöfer F, Ardyna M (2024) Seafloor primary production in a changing Arctic Ocean. PNAS Nexus 121 | doi: 10.1073/pnas.2303366121