Search for: All records

Tourism contributes to groundwater pollution, but quantifying its exact impact is challenging due to the presence of multiple pollution sources. However, the COVID-19 pandemic presented a unique opportunity to conduct a natural experiment and assess the influence of tourism on groundwater pollution. One such tourist destination is the Riviera Maya in Quintana Roo, Mexico (specifically Cancun). Here, water contamination occurs due to the addition of sunscreen and antibiotics during aquatic activities like swimming, as well as from sewage. In this study, water samples were collected during the pandemic and when tourists returned to the region. Samples were taken from sinkholes (cenotes), beaches, and wells then tested using liquid chromatography for antibiotics and active ingredients found in sunscreens. The data revealed that contamination levels from specific sunscreens and antibiotics persisted even when tourists were absent, indicating that local residents significantly contribute to groundwater pollution. However, upon the return of tourists, the diversity of sunscreen and antibiotics found increased, suggesting that tourists bring along various compounds from their home regions. During the initial stages of the pandemic, antibiotic concentrations were highest, primarily due to local residents incorrectly using antibiotics to combat COVID-19. Additionally, the research found that tourist sites had the greatest contribution to groundwater pollution, with sunscreen concentration increasing. Furthermore, installation of a wastewater treatment plant decreased overall groundwater pollution. These findings enhance our understanding of the pollution contributed by tourists in relation to other pollution sources. 

The Yalahau region, located in the northeastern portion of the Yucatán Peninsula, hosts a series of elongated depressions trending north/south in the direction of Isla Holbox, identified as the Holbox Fracture Zone. Previous studies have explored the geomorphology and various hydrologic characteristics of the Yucatán Peninsula; however, there is a paucity of data concerning the interior region where the fractures are located. Strontium isotope ratios and major ion geochemistry data of the surface water and groundwater of this region serve as a hydrogeochemical fingerprint, aiding in constraining the hydrological boundaries, determining flow paths, and characterizing hydrogeochemical processes that impact the composition of the groundwater within the region. 87Sr/86Sr isotope ratios indicate a different signature than the surrounding bedrock Sr ratio, suggesting that the flow throughout the Yalahau region is moving through channels faster than that of much of the Yucatán. Through major ion geochemistry and 87Sr/86Sr isotope ratios, we were able to delineate at least two flow paths within the Yalahau region and identify a point of saline intrusion at least 35 km from the coast. Gaining an understanding of the hydrogeochemistry and water flow regions is crucial in determining the impact of various activities (e.g., extensive tourism, drinking water withdrawal, wastewater discharge/injection) that occur within the Yucatán Peninsula. 

The Mexican Caribbean is part of the Mesoamerican Barrier Reef System, considered the second largest reef system globally. This system, as well as inland aquatic ecosystems, are at risk of contamination due to the intensive use of sunscreen by the tourists who visit the Riviera Maya each year. At present, the regulation and management of sunscreens are inconsistent, with most policies and legislation focused on the protected marine areas with little current focus on inland aquatic ecosystems. An estimated 229.76 tons of sunscreen are used annually, with residues putting the health of the marine and freshwater aquatic ecosystems and residents at risk. Groundwater is used recreationally (e.g., tourists swimming in sinkholes or cenotes) and as household drinking water. To understand the environmental impacts of sunscreen use and the management implications, a mixed-methods study was carried out, combining survey and interview data on how tourists use sunscreen and their perceptions of discharge of sunscreens into the water, with analysis of regional, national and international policies and legislation. Our findings of touristic behaviors, gaps in current legislation, and the pollution implications of different sunscreen types provide useful information for future decision-making and the creation of stronger environmental regulations. 

Since 2011, tourism to Mexico’s Yucatán Peninsula has been heavily impacted by large masses of sargassum seaweed washing up on the beaches, with the largest seaweed event occurring in 2019. Seaweed deters beach tourism, potentially shifting tourism inland towards other activities such as swimming in cenotes (sinkholes). Our mixed methods study combined data from surveys of visitors to the region, interviews with tourists and tour operators, thematic analysis of newspaper articles, laws and policies and analysis of water samples from a cenote to understand the environmental impact on cenotes of this shifting tourism industry. We identified intentional efforts by the tourism industry to encourage cenote tourism in response to the seaweed problem, and our survey and interview data confirmed that tourists are choosing to visit cenotes in lieu of beaches. Water samples from one tourist cenote in 2019 indicated increased pollution relative to previous years. Current regulations and management of tourist cenotes are weak, creating the potential for significant long term harm to the environment and to the water sovereignty of surrounding communities. Regulation of cenotes should be strengthened to protect these fragile karst ecosystems and to give local and indigenous residents a formal voice in the management process.