Laguna de Tecocomulco. 27/11/03; Hidalgo; 1,769 ha; 19°52'N 098°23'W. Lying at 2514 m in the endorrheic basin of Tecocomulco, considered to be the last remnant of the ancient freshwater wetland system that dominated the Mexico Valley Basin in the centre of the country. Underlying aquifers are recharged through the lake, whose water level fluctuations are high. The site is noteworthy for 15 duck species, with congregations of Ruddy Ducks Oxyura jamaicensis of up to 5000 individuals, and of Moorhens Gallinula chloropus of up to 3000. The endangered Axolotl salamander Ambystoma mexicanum also inhabits the site. The Asian Carp (Cyprinus carpo) is commercially exploited by local fishermen. There are quotas for waterfowl hunting, which takes place especially during the winter. Erosion in the basin caused by agricultural activities and overgrazing provokes a high rate of sedimentation and turbidity in the lake. To address this problem, erosion control and forestation projects have been undertaken for basin management. Different universities are engaged in research and training. Ramsar site no. 1322. Most recent RIS information: 2003.