Blue carbon fluxes and inventories in mangroves associated with an anthropized coastal lagoon

Abstract

Mangroves, along with seagrasses and saltmarshes, are among the coastal ecosystems known as blue carbon ecosystems. These ecosystems are natural carbon sinks, relevant to mitigate global warming because they are able to sequester significant amounts of CO2 for biomass production, and to store organic matter in sediments for a very long time. We present the temporal evaluation of fluxes (g m-2 year-1) and inventories (Mg ha-1) of organic carbon (Corg) from sediment cores collected in mangroves areas associated with the coastal lagoon Estero de Urías, in Mazatlán, Sinaloa. The work strategy included the geochemical characterization of sediments by elemental composition analysis through X-ray fluorescence spectrometry to evaluate changes in sediment origin (terrestrial or marine); the determination of the grain size distribution to evaluate changes in the hydrodynamics of the study sites; and the quantification of Corg concentrations with an elemental analyzer. Finally, we estimated the economic cost of the impacts of CO2 emissions caused by the oxidation of Corg due to potential perturbations of the study sites. This information is an additional component of the economic benefits of the preservation of mangrove ecosystems, relevant in coastal wetland management plans, since mangrove conservation contributes to the reduction of greenhouse gas emissions and could be used as part of an ecosystem-based adaptation to climate change strategy in tropical and subtropical zones around the world.