Change in fish fauna as indication of aquatic ecosystem condition in Rio Grande de Morelia-Lago de Cuitzeo Basin, Mexico
- Inst. Politecnico Nacional, Mexico Distrito Federal (Mexico). Escuela Nacional de Ciencias Biologicas
- Wisconsin Dept. of Natural Resources, Monona, WI (United States)
The Rio Grande de Morelia-Lago de Cuitzeo basin in west central Mexico has experienced major increases in water pollution from a rapidly growing human population. The authors examined changes in the long-term distribution of fishes in relation to water quality and quantity in order to assess the condition and health of aquatic ecosystems in the basin. Sampling between 1985 and 1993 revealed that five (26%) of the 19 native fish species known from the basin had been extirpated. Two of these were endemics, Chirostoma charari and C. compressum, and they are presumed extinct. Twelve (63%) of the remaining species had declines in distribution. Sixteen (80%) of the 20 localities sampled had lost species. The greatest declines occurred in Lago de Cuitzeo proper and in the lower portion of the Rio Grande de Morelia watershed. Species losses from the lake were attributable to drying and hypereutrophication of the lake because of substantial reductions in the amount and quality of tributary inputs, whereas losses from the Rio Grande de Morelia watershed were the result of pollution from agricultural, municipal, and industrial sources, especially in the region around the city of Morelia. Three localities in the upper portion of the Rio Grande de Morelia watershed--Cointzio reservoir, La Mintzita spring, and Insurgente Morelos stream--contained most of the remaining fish species diversity in the basin and deserve additional protection. Fish faunal changes indicated major declines in the health of aquatic ecosystems in the Morelia-Cuitzeo basin.
- OSTI ID:
- 6282153
- Journal Information:
- Environmental Management, Vol. 24:1; ISSN 0364-152X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ECOSYSTEMS
BIOLOGICAL INDICATORS
FISHES
LAKES
MEXICO
SPECIES DIVERSITY
WATER POLLUTION
ANIMALS
AQUATIC ORGANISMS
DEVELOPING COUNTRIES
ECOSYSTEMS
LATIN AMERICA
NORTH AMERICA
POLLUTION
SURFACE WATERS
VERTEBRATES
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology