Degradation factors and their environmental impacts on the mangrove ecosystem of the Mallorquin Lagoon, Colombian Caribbean

Mangrove forests are threatened by natural and anthropogenic factors resulting in their degradation and the loss of the ecosystem services they provide. The analysis of degradation factors (DFs) is essential to guide mangrove conservation efforts. The aims of this study were to identify DFs and perform an environmental impact assessment (EIA) on their impacts over the mangroves of Mallorquin Lagoon, Colombian Caribbean. The main mangrove DFs were documented during field campaigns. Also, mangrove structural characteristics, physicochemical conditions, and pollutant concentrations in water and sediments were measured to determine the ecosystem degradation status. Subsequently, the qualitative methodology of EIA allowed calculating the importance of the impacts resulting from DFs on the ecosystem components. The main DFs identified were wastewater discharges, unregulated litter dumps, mangrove logging, and urban sprawl. Mangrove species in Mallorquin Lagoon included Rhizophora mangle , Laguncularia racemosa , and Avicennia germinans , the latter being the one with the highest density, basal area, and importance value index. Mangrove sediments showed high concentrations of Cu, Ni, Cr, and Zn that could lead to adverse effects on the mangrove's aquatic organisms. The EIA indicated that water and soil quality were severely impacted by wastewater discharges. While unregulated litter dumps had moderate impacts, mangrove logging and urban sprawl caused significant changes in the ecosystem, critically impacting water, soil, and forest integrity. Efficient control of urban sprawl, ecological restoration of the deteriorated areas and effective environmental protection measures are required to conserve Mallorquin Lagoon, a fragmented Ramsar wetland.