Frank DAVID

Previous BOREA member

Research Engineer - LAMENTIN Program

Mangroves play a crucial role in carbon sequestration. Indeed, they are considered a carbon sink with storage efficiency far greater than any other type of forest worldwide (Donato et al., 2011). This ecosystem thus contributes to mitigating the effects of climate change induced by greenhouse gases. Despite their relatively small surface area (about 0.7% of the total global intertropical forests according to Giri et al., 2011), these coastal and estuarine wetlands are characterized by high primary production (over 218 Tg C yr-1; Bouillon et al., 2008) and an estimated significant carbon reservoir, accounting for 14% of global oceanic carbon sequestration (Alongi, 2014). This carbon captured by a marine ecosystem is known as blue carbon. More broadly, mangroves also serve as sources of organic and inorganic carbon for intertropical coastal zones, significantly contributing to the maintenance of important aquatic primary and secondary production.

Mangroves are facing increasingly strong anthropogenic pressures that affect hydrological regimes and the functionalities of intertropical coastal and estuarine areas. The development of shrimp farms and the growing urbanization along the coast lead to organic pollution of the environment. This pollution causes eutrophication, accelerating algae proliferation and the accumulation of organic matter (OM). This input of labile OM would increase the mineralization rate of refractory OM and potentially its burial. This phenomenon of over-mineralization of soil OM is called the "priming effect." It contributes to the emissions of carbon dioxide (CO2), a greenhouse gas, and could be intensified in cases of eutrophication. As for the other notable greenhouse gas, methane (CH4), there are still many uncertainties about its balance within this ecosystem (Chen et al., 2010). However, the emission of these gases into the atmosphere is influenced by crab activity, particularly through the presence of burrows (Kristensen et al., 2008). Similarly, these decapods, especially fiddler crabs (Ocypodidae), play a role in the distribution of OM in subsurface sediment (Natálio et al., 2017).

The main objective of the LAMENTIN project is to highlight the effect of eutrophication on the quality of available organic matter, its storage (blue carbon), and its utilization by consumers (primarily crabs) in the functioning of the ecosystem, and more broadly on the dynamics of greenhouse gases within the Lamentin mangrove in Martinique.