Coastal ecosystems (i.e., mangroves, tidal marshes and seagrasses) are globally important CO₂ sinks, yet they rank among the most threatened ecosystems on Earth. Extensive research over the last decade has quantified blue carbon (BC) storage across these habitats to obtain national and global estimates and evaluated the climate benefits linked to conservation and restoration actions. However, to include BC ecosystems in national inventories, nationally determined contributions or carbon-trading schemes, reproducible and holistic assessments of carbon storage and greenhouse gas (GHG) fluxes are needed. Here we identified 15 common research procedures that can be improved to strengthen BC science and suggest best practices to align BC research with policy and management. Recommendations are provided for: (1) planning and field practices, including technical (e.g. minimum sample size required for reducing uncertainties) and ethical (i.e. avoiding helicopter research) aspects; (2) analytical procedures, which include handling of coarse plant material within the soil and modelling of carbon burial rates; and (3) the interpretation and upscaling of results, e.g., that large carbon stocks do not necessarily reflect high carbon sequestration rate, and that all GHG fluxes influence the net CO₂ sink capacity of BC habitats. We conclude that improved BC practices will help generate high-quality carbon credits and inventories based on credible and conservative calculations of baselines, additionality, leakage and permanence, moving us towards the uptake of large-scale BC projects.

Tutorial/Invited: Tutorial

Primary Presenter: Martin Dahl, Södertörn University (martin.dahl@sh.se)

Authors:

Martin Dahl, School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden & Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Científicas. Blanes, Spain  ()

Paul Lavery, Centre for Marine Ecosystems Research, School of Natural Sciences, Edith Cowan University, Joondalup WA, Australia  ()

Inés Mazarrasa, Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Científicas. Blanes, Spain & IHCantabria—Instituto de Hidráulica Ambiental de la Universidad de Cantabria, Parque Científico y Tecnólogico de Cantabria, Santander, Spain  ()

Jimena Samper-Villarreal, Centro de Investigación en Ciencias del Mar y Limnología, CIMAR, Ciudad de la Investigación, Universidad de Costa Rica, San José, Costa Rica  ()

Maria Adame, Australian Rivers Institute, Centre for Marine and Coastal Research, Griffith University, Brisbane, QLD, Australia  ()

Stephen Crooks, Silvestrum Climate Associates, Sausalito, California 94965  ()

Carlos Duarte, Red Sea Research Centre (RSRC) and Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia  ()

Daniel Friess, Department of Earth and Environmental Sciences, Tulane University, New Orleans, Louisiana 70118, USA   ()

Dorte Krause-Jensen, Department of Ecoscience, Aarhus University, 8000 Aarhus C, Denmark  ()

Carmen Leiva Dueñas, Department of Ecoscience, Aarhus University, 8000 Aarhus C, Denmark  ()

Catherine Lovelock, School of Biological Sciences, University of Queensland, St Lucia, Australia  ()

Peter Macreadie, Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University VIC, Australia  ()

Núria Marbà, Global Change Research Group, Institut Mediterrani d’Estudis Avançats (CSIC-UIB), Esporles, Spain  ()

Pere Masqué, Centre for Marine Ecosystems Research, School of Natural Sciences, Edith Cowan University, Joondalup WA, Australia & International Atomic Energy Agency, Principality of Monaco, Monaco  ()

Miguel Mateo, Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Científicas. Blanes, Spain  ()

Oscar Serrano, Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Científicas. Blanes, Spain & Centre for Marine Ecosystems Research, School of Natural Sciences, Edith Cowan University, Joondalup WA, Australia  ()