Mangroves are coastal environments that provide diverse resources to adjacent ecosystems because of their high productivity and protection from tidal action. However, this ecosystem has been heavily threatened and is in great danger of disappearing. Due to its productivity and input of allochthonous organic matter, carbon cycling in mangroves is an ecological service of paramount importance not only for the mangrove itself, but also for adjacent ecosystems that receive released carbon and on a global scale, but the imbalance of this dynamics can generate an increase in carbon release contributing to the increase of greenhouse gases in the atmosphere. Therefore, understanding the dynamics of organic matter decomposition in mangrove sediments from ecological succession to the genes involved is of paramount importance at a time when climate change threatens the survival of this ecosystem. For this reason, this project aims to evaluate the dynamics of the microbial community during the decomposition of organic matter in mangrove sediments, determining its composition and the emission of greenhouse gases released in the sediments in different states of preservation, evaluating how this process occurs in nature and how the anthropic effect affects it. In addition, this project proposes to identify by metagenomic and metatranscriptomic the metabolic pathways involved in the degradation of organic matter in these sediments. This is the key knowledge that is sought through this project, to glimpse the phylogenetic and metabolic biodiversity in the process of decomposition of organic matter in mangroves, allowing to identify how the anthropic effects can compromise the functioning of mangroves contributing to climate change