Coral reefs and the ecological, social, and economic benefits that they provide are seriously endangered by a colossal number of threats. This study was conducted in marine protected area (MPA) in the Mexican Caribbean. The purpose of this study was to provide results that can be directly applied by MPA managers to improve coral reef conservation and management. Characterization of four coral reef sites and stressors described in a proxy map were integrated into a comparative resilience assessment. Sites ranged from 16.5% to 3.5% coral cover and 47.5% to 12% macroalgal cover. Stressor distribution and intensity was highest near the Puerto Morelos town center and followed general water current patterns. Fishing, tourism, and pollution were identified as major stressors on which management can positively influence. The results of this study provide managers throughout the Caribbean a managerial tool chest to improve management efficacy and bolster conservation initiatives.

The Mexican Caribbean tourism sector is highly exposed to hurricane activity, yet coastal tourism is also a major driver influencing regional biophysical and social vulnerability to climate risks. Drawing on a political ecology approach and a vulnerability assessment, this study asks how experiences with extreme hurricane events in the Mexican Caribbean shape climate change adaptation in the regional tourism sector. This study uses multiple methods, scales and field sites to (a) examine how biophysical vulnerability to extreme hurricanes affects the tourism sector, (b) explain the changing conditions of social vulnerability linked to hurricane damage in the tourism sector and (c) assess the present and future opportunities and obstacles for adaptation planning. The main findings show that the region is experiencing a phase of unprecedented high intensity hurricanes. It is uncertain, however, whether changes in hurricane activity exceed natural multi-decadal variability. Tourism is one major driver of land use changes which have resulted in some of the world’s fastest increase in coastal urban sprawl. Most tourism infrastructure is located in areas with the greatest exposure to hurricanes. Hurricane Wilma which hit the region in 2005 is the most expensive natural disaster in the history of the Mexican insurance industry. Hotels have showed a high ability to recover operations after hurricanes. There is a high penetration of insurance ownership in hotels and there is substantial mobilization of public and private financial and human resources during hurricane disasters. Hotel responses to hurricanes, however, tend to be reactive and autonomous. One important consequence of hurricanes is that hoteliers in the interest to reduce operational costs, fire those workers with the weakest labour rights. Thus, hotel workers suffer from ‘double exposure’, a situation where hotel workers are confronted with the consequences of climate change while simultaneously suffering the consequences of globalization and neoliberal policies which have reduced the power of unions and weakened access to social security. The Mexican government has created a national climate change strategy and its operational programme which has led to the consolidation of an adaptation organizational structures at the national and state levels. I conclude, however, that adaptation planning may not result in the necessary actions on the ground since local actors are not well integrated yet into such efforts. This study shows the importance of regional adaptation research that takes into account perspectives from both the physical and social sciences. This study highlights the importance of interactions between local actors, the larger socioeconomic and political economy context to inform adaptation planning and policy.

Bahia de la Ascension (BA) is a pristine, shallow, karst bay located in the Mexican Caribbean, a region experiencing rapid population growth stimulated by intense tourism development. The overall objective of this study was to address the natural hydrographic variability of this inherently vulnerable ecosystem and assess its influence on a key habitat, the seagrass. The chapters follow the three-branched nature of the study which tackled the connected ecosystem issues of coastal hydrology, physical dynamics of flow and circulation, and the ecological dynamics of the seagrass species Thalassia testudinum in BA. Freshwater input to BA is primarily by submerged groundwater discharges and surface runoff; both sources are derived from fissures in the aquifer but feature distinct water quality due to the interaction with adjacent wetlands. Hurricanes explain 36 percent of the interannual precipitation variability in the region. The water balance indicates a persistent net outflow from BA to the adjacent shelf, suggesting an intense exchange across inlets. Both diurnal and semidiurnal tidal frequencies are attenuated in the inner bay, where a meteorologically-induced subtidal water level increase may occur during four-day southeasterly winds. A clear SW-NE salinity gradient was established during dry and rainy seasons, with a strong tidally-driven marine influence throughout the central basin, and a perennial mesohaline ambient in the southwestern-most bay, where hydrodynamics are primarily controlled by wind stress. Thalassia testudinum is the dominant seagrass species in BA, occupying ~90 percent of the substrate, including the freshwater-influenced inner bay. High nutrient inputs, including phosphorus which might have limiting effects in karst environments, along with the wind-driven circulation controlling water residence times are associated with the successful development of T. testudinum (up to 1,461.23 g DW m-2) within the SW bay. Farthest into the central basin, Thalassia consistently exhibited an inverse correlation between abundance and density of shoots. This pattern was enhanced under exceptional precipitation and inputs of denuded organic matter resulting from hurricanes making landfall on this region. The relationship between nutrient distribution and the above/belowground ratio suggested that Thalassia growing in BA favors the development of the aerial component as nutrients availability increases. This study provides a basic understanding of the most important processes molding the patterns of variability exhibited by T. testudinum in Bahia de la Ascension. The salinity gradient and external nutrient supply, along with the hydrodynamic component, define the spatial scale at which the connectivity between the adjacent wetland, the bay, and the shelf may occur.