Title: Present status and management of coastal lagoons in the Sabana–Camagüey Archipelago I: environmental baseline at lagoons of Cayo Sabinal

Management actions are necessary to protect tropical coastal lagoons from present and future natural and anthropogenic impacts. Three coastal lagoons located in Cayo Sabinal (Sabana-Camagüey Archipelago, Cuba) were sampled on five dates distributed between 2015 and 2017. Physicochemical parameters (temperature, salinity, pH, dissolved oxygen), dissolved inorganic nutrients and total phosphorus and nitrogen were sampled at several sites in each lagoon. We found that the three lagoons are choked, hypersaline, hypertrophic and highly dependent on seasonal precipitation due to restricted water exchange with the ocean. Los Caimanes lagoon showed the highest mean salinity (90.8 PSU), the lowest level of dissolved oxygen (2.1 ± 1.0 mg L − 1 ) and the highest soluble reactive and total phosphorus (0.80 ± 1.45 µM and 8.2 ± 6.4 µM, respectively). La Salina lagoon showed the highest level of dissolved inorganic and total nitrogen (95.5 ± 209.8 µM and 921.9 ± 1984.1 µM, respectively). Nutrients were very variable -spatially and seasonally- at each lagoon. The construction of roads has likely reinforced the isolation of the lagoons, causing the most severe impact on the lagoons, particularly regarding salinity levels, which dramatically increase during the dry season because of the region´s microtidal range. Restoration actions must focus on the building of culverts to increase water exchange between the lagoons and the sea, and among the isolated sections of Tortuguilla lagoon. Management and restoration actions are proposed for coming tourism development projects in order to make a sustainable use of these fragile but important tropical coastal ecosystems, among which Los Caimanes lagoon outstands as a potential site for the study of microbialite communities.