Análisis espacio temporal de la erosión y acreción costera en Gandoca, Limón, Costa Rica (2005-2019) e implicaciones socioambientales desde la perspectivacomunitaria

The southern Caribbean coast of Costa Rica has experienced accelerated coastal erosion over recent decades, with Gandoca beach emerging as one of the most critical erosion hotspots in the region. This study analyzes erosion and accretion rates along the Gandoca coastal sector during the 2005–2019 period and examines community perceptions of this process. The methodology comprises two components: shoreline change rates were estimated using the DSAS extension within a Geographic Information System, and local perceptions of coastal erosion were explored through a qualitative approach using semi-structured interviews. Results indicate that coastal erosion is severe along most of the beach, with rates ranging from -1.37 m/yr to -2.92 m/yr. A notable exception occurs in a sector upstream of the Sixaola River mouth, where accretion is recorded at 1.43 m/yr; by contrast, the river mouth sector exhibits a net landward displacement of -52 m. Community members associate coastal erosion with land loss from beach retreat and beach-face reduction, and with the decline or absence of sea turtle nesting. This last factor has led to a reduction in tourism-derived income, adversely affecting livelihoods within the Gandoca-Manzanillo National Wildlife Refuge.