This study presents limnological and morphological characteristics, physical and chemical properties of waters, and geochemistry of surface sediments for 63 aquatic ecosystems located on the karst Yucatán Peninsula and surrounding areas of Belize and the Guatemalan highlands and eastern lowlands. Our principal goal was to classify the aquatic systems based on their water variables. A principal component analysis (PCA) of the surface water chemistry data showed that a large fraction of the variance (29%) in water chemistry is explained by conductivity and major ion concentrations. The broad conductivity range, from 168 to 55,300 μS cm-1 reflects saline water intrusion affecting coastal aquatic environments, and the steep NW-S precipitation gradient, from ~450 to>3,200 mm year-1. Coastal waterbodies Celestún and Laguna Rosada displayed the highest conductivities. Minimum surface water temperatures of 21.6°C were measured in highland lakes, and warmest temperatures, up to 31.7°C, were recorded in the lowland waterbodies. Most lakes showed thermal stratification during the sampling period, with the exception of some shallow (<10 m) systems. Lakes Chichancanab, Milagros, and Bacalar displayed sulfate-rich waters. Waters of sinkholes had relatively high conductivities (<3,670 μS cm-1) and a broad range of δ18O values (-4.1 to +3.8%). Ca, HCO3, and SO4 dominated the waters of the lowland lakes, whereas Na was the dominant cation in highland lakes. Coastal aquatic ecosystems were dominated by Na and Cl. Cluster analysis based on surface water variables classified aquatic environments of the lowlands and highlands into three groups: (1) lowland lakes, ponds, wetlands, and coastal waterbodies (2) highland lakes, and (3) sinkholes and rivers. A broad trophic state gradient was recorded, ranging from the eutrophic Lake Amatitlán and the Timul sinkhole to oligotrophic Laguna Ayarza, with the highest water transparency (11.4 m). We used major and trace elements in surface sediments to assess pollution of waterbodies. Lakes Amatitlán, Atescatempa, El Rosario, Cayucón, Chacan-Lara, La Misteriosa, rivers Subín and Río Dulce, the wetland Jamolún, and the sinkhole Petén de Monos showed evidence of pollution and urban development. Their surface sediments displayed high concentrations of As, Cu, Fe, Ni, Pb, Se, Zn, and Zr, which suggest moderate to strong pollution.
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Acknowledgments We are grateful to many people who helped us during our fieldtrips in Mexico, Belize, and Guatemala. We extend thanks to the following people and agencies: Aaron Lewis (University of Belize), the Forestry and Fisheries Departments (Belize), Margarita Palmieri, Margaret Dix, Roberto Moreno, Eleonor de Tott (Universidad del Valle de Guatemala), Rodrigo Morales, FranklinHerrera(CONAP,Guatemala), IsmaelOrdóñez (AMSCLAE, Guatemala), Julio Morales Cancino (AMPI, Guatemala), Roderico Pineda, Mario Buch (Trifinio, Guatemala), Secretaría de Relaciones Exteriores (SRE, Mexico), Comisión Nacional de Acuacultura y Pesca (CONAPESCA, Mexico), Alberto de Jesús Navarrete (ECOSUR-Chetumal, Mexico), Rita Löhr, Benjamin Gilfedder, Yvonne Hermanns, Harald Biester (Institut für Umweltgeologie, TU Braunschweig, Germany), Douglas Schnurrenberger, Dustin Grzesik, David Klassen, José Harders, Carmen Herold, Bessie Oliva, Alma Quilo, Gabriela Alfaro, Jacobo Blijdenstein, Melisa Orozco, Silja Ramirez, Luis Toruño, Mario Cruz, Javier Pérez y Pérez, Carolina Alvarado de Pérez, and two anonymous reviewers for constructive comments. We are grateful for financial support provided by the Deutsche Forschungsgemeinschaft (DFG, grant Schw 671/3) and start-up money to A.S. provided by the Technische Universität Braunschweig.
Copyright 2011 Elsevier B.V., All rights reserved.
- Neotropical aquatic ecosystems
- Physical and chemical water variables
- Surface sediment geochemistry
- Yucatán Peninsula