Digitale Bibliotheek
Sluiten Bladeren door artikelen uit een tijdschrift
 
<< vorige    volgende >>
     Tijdschrift beschrijving
       Alle jaargangen van het bijbehorende tijdschrift
         Alle afleveringen van het bijbehorende jaargang
           Alle artikelen van de bijbehorende aflevering
                                       Details van artikel 15 van 35 gevonden artikelen
 
 
  Fish as indicators of environmental quality in the Rio Lerma Basin, Mexico
 
 
Titel: Fish as indicators of environmental quality in the Rio Lerma Basin, Mexico
Auteur: Soto-Galera, Eduardo
Diaz-Pardo, Edmundo
Lopez-Lopez, Eugenia
Lyons, John
Verschenen in: Aquatic ecosystem health & management
Paginering: Jaargang 1 (1998) nr. 3-4 pagina's 267-276
Jaar: 1998
Inhoud: The Rio Lerma basin, one of the most important hydrographic regions of Mexico, has a distinctive fish fauna. In recent years, the basin has experienced major increases in human populations and industrial and agricultural development. To assess the health of aquatic ecosystems in the Lerma basin, we analyzed the current status and long-term trends in fish species occurrence at 116 widely distributed sites in relation to water quality and land use information. Our results reveal a staggering and unprecedented level of environmental degradation. Over 50% of our sites are no longer capable of supporting fish life. Many sites have completely disappeared because of groundwater extraction, water diversions, or urbanization. The Alto Lerma subprovince has experienced the greatest negative impacts, but no region of the basin has escaped significant damage. Only 15% of our sites currently support species that we classify as sensitive to environmental degradation, and most of these sites are on small headwater streams or isolated highland lakes that are protected as parks or municipal water supplies. Only one lowland river, the Rio Turbio, retains relatively good environmental quality. Forty percent of the 42 species native to the basin have experienced major declines in frequency of occurrence, and three endemic species, Algansea barbata, Chirostoma charari, and Chirostoma compressum may be extinct. Conservation efforts should focus on protecting all sites that still hold native fishes, with particular emphasis on the Rio Turbio.
Uitgever: Taylor & Francis
Bronbestand: Elektronische Wetenschappelijke Tijdschriften
 
 

                             Details van artikel 15 van 35 gevonden artikelen
 
<< vorige    volgende >>
 
 Koninklijke Bibliotheek - Nationale Bibliotheek van Nederland