Groundwater Pollution in a Karstic Region (NE Yucatan): Baseline Nutrient Content and Flux to Coastal Ecosystems

Abstract

The quality of groundwater is threatened in karstic regions with very high population growth, such as the eastern coast of Yucatan. As polluted groundwater flows towards the ocean, coastal ecosystems and coral reefs may also be affected. Pollution and the interaction between the coastal aquifer and the reef lagoon were assessed at a developing area (Puerto Morelos, NE Yucatan Peninsula) within the Mesoamerican Coral Reef System. Coastal environments along the land-sea gradient (wells, mangroves, beaches, submarine springs, the reef lagoon, and the open sea) were sampled. Silicate and salinity were used as tracers of groundwater and seawater, respectively. Their patterns evidence water flow and mixing among these coastal environments. High nitrate concentrations (268.6 μM) and coliform bacteria densities indicate groundwater pollution in most of the wells sampled and also in mangroves, beaches, and submarine springs. Phosphorous content peaks (14.2 μM) in mangroves, where it is likely released due to reducing conditions in the sediments. Nitrogen flux toward the lagoon reef through groundwater discharge is estimated at 2.4 ton N km −1 year −1 and phosphorous at 75 to 217 kg P km −1 year −1 . These results provide evidence of the need for more detailed groundwater studies and for the integrated management of aquifers and coastal ecosystems in karstic regions.

Restoring the environment, revitalizing the culture: cenote conservation in Yucatan, Mexico

“…In Yucatan, most groundwater research has focused on its hydrology and environmental problems (Hernández-Terrones et al 2011, Polanco-Rodríguez et al 2015. This is of importance since successful monitoring and management often calls for a clear understanding of the groundwater system.…”

“…However, even though local people possess values and some knowledge about water, they continue to have a heavy impact on the resource including wastewater discharges and poor solidwaste disposal practices. Problems include water resource scarcity and pollution due to development, biodiversity loss, and resource degradation (Hernández-Terrones et al 2011, Metcalfe et al 2011, Lopez-Maldonado et al 2017; Fig. 1).…”

Managing for Resilience: Practical Applications of Marine Science to Improve Natural Resource Management: A Case Study in the Puerto Morelos Marine Protected Area

“…Submarine springs, locally known as ojos de agua, are present throughout the lagoon and are capable of transporting freshwater and contaminants from the terrestrial environment to the marine environment (Ward, 1985;Ruíz-Rentería et al, 1998;Carruthers et al, 2005;Hernández-Terrones et al, 2010). An unidentified number of submarine springs are interspersed within the lagoon habitat in the PNAPM.…”

“…transported by the ojos de agua present within the PNAPM vary greatly depending on weather conditions and water source characteristics (Payton et al, 2006;Hernández-Terrones et al, 2010;M. Ladd, pers.…”

“…The eastern coast of the Yucatan Peninsula, which includes Puerto Morelos, is currently undergoing rapid development and population growth (Coronado et al, 2007;Murray 2007;Hernández-Terrones et al, 2010). Increased runoff and sedimentation rates associated with coastal development can decrease coral cover and biodiversity (Cortes & Risk, 1985;Hodgson, 1990;Shimoda et al, 1998), coral settlement and survivorship rates (Babcock & Smith, 2002;Birrel et al, 2005), and reduce egg fertilization in some coral species (Harrison & Ward, 2001).…”