Water quality monitoring in tourist coastal areas to enhance community participatorymanagement of marine-coastal resources, Guanacaste, Costa Rica.

The North Pacific coast of Costa Rica has had the largest infrastructure growth for the commercial, urban and tourism sectors in the country. This development has contributed to the economic progress of the region with higher incomes and employment generation, but has caused social and environmental problems in recent decades. The shortage of water sources, salinization of aquifers, problems of contamination of the estuaries and beaches mainly due to nutrients and microbiological pollutants from poor wastewater management have generated conflicts between different sectors, mainly between investors and the local population. The Water Resources Centre for Central America and the Caribbean (HIDROCEC-
UNA) has developed a research process in recent years in this area, where 10 sampling points were evaluated in seven tours from 2022 to 2024 to analyze nutrients, measurement of in situ parameters, microbiological and physicochemical parameters. During the process, different forms and types of pollution that are reaching the water bodies and the coast were identified, their spatial location and their vulnerability with respect to drinking water
sources. The analysis of the quality of coastal waters and effluents reaching the sea showed that 3 of the 10 points exceed the presence of microbiological pollutants for recreational uses and that a decrease in water quality in 5 of the parameters analyzed (fecal coliforms, Enterococci, turbidity, dissolved oxygen and saturation, ammonium) is foreseen in the future. The results were presented to the social actors in the area in order to strengthen advocacy and environmental management. The construction of a participatory work agenda was achieved through inclusive strategies, the search for the involvement of government institutions and the promotion of citizen science to improve the protection of environmental and coastal resources.