Barra de Navidad Beach, Mexico. Over the last thirty years, landfills in the coastal lagoons of Tule and Barra de Navidad, in Jalisco, Mexico, as well as deforestation and the construction of inappropriate infrastructure, have altered the dynamics of ecosystems at the nearby beaches of Melaque, San Patricio and Barra de Navidad. Consequently, there is acute sedimentation in the Barra de Navidad lagoon and severe erosion of the coastal spit and the attractive, long beach, which threaten the future of the local community. Monitoring has shown that the alteration of flow patterns in the lagoon has brought about a decrease in the amount of sand transported to the beaches and an increase in the magnitude of the wave induced currents along the waterfront. (Photograph courtesy of the Secretaría de Turismo of the Municipality of Cihuatlán, Jalisco, Mexico.)