Spatial and temporal variation of methane emissions in the coastal Balearic Sea, Western Mediterranean

Susana Flecha; Diego Rueda; Mercedes de la Paz; Fiz F Pérez; Eva Alou-Font; Joaquín Tintoré; Iris E Hendriks

doi:10.1016/j.scitotenv.2022.161249

Spatial and temporal variation of methane emissions in the coastal Balearic Sea, Western Mediterranean

Sci Total Environ. 2023 Mar 20:865:161249. doi: 10.1016/j.scitotenv.2022.161249. Epub 2022 Dec 30.

Authors

Susana Flecha¹, Diego Rueda², Mercedes de la Paz³, Fiz F Pérez³, Eva Alou-Font⁴, Joaquín Tintoré⁵, Iris E Hendriks²

Affiliations

¹ Instituto Mediterráneo de Estudios Avanzados (IMEDEA-CSIC-UIB), Esporles, Spain. Electronic address: susana.flecha@csic.es.
² Instituto Mediterráneo de Estudios Avanzados (IMEDEA-CSIC-UIB), Esporles, Spain.
³ Instituto de Investigaciones Marinas (IIM-CSIC), Vigo, Spain.
⁴ King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
⁵ Instituto Mediterráneo de Estudios Avanzados (IMEDEA-CSIC-UIB), Esporles, Spain; Balearic Islands Coastal Observing and Forecasting System (SOCIB), Palma, Spain.

PMID: 36587676
DOI: 10.1016/j.scitotenv.2022.161249

Abstract

Methane (CH₄) gas is the most important GHG after carbon dioxide, with open ocean areas acting as discreet CH₄ sources and coastal regions as intense but variable CH₄ sources to the atmosphere. Here, we report CH₄ concentrations and air-sea fluxes in the coastal area of the Balearic Islands Archipelago (Western Mediterranean Basin). CH₄ levels and related biogeochemical variables were measured in three coastal sampling sites between 2018 and 2021, with two located close to the densely populated island of Mallorca and one in a pristine area in the Cabrera Archipelago National Park. CH₄ concentrations in seawater during the study period ranged from 2.7 to 10.9 nM, without significant differences between the sampling sites. Averaged estimated CH₄ fluxes during the sampling period for the three stations oscillated between 0.2 and 9.7 μmol m^-2 d^-1 according to a seasonal pattern and in general all sites behaved as weak CH₄ sources throughout the sampling period.

Keywords: Balearic Sea; Climate change; Coastal monitoring; Greenhouse gases; Mediterranean Sea; Methane flux.