Article: Biological assessment of Tecate Creek (U.S.-Mexico) with special regard to self-purification.

Abstract.--Macroinvertebrate organisms were sampled at four sites on Tecate Creek (U.S.-Mexico) and quantitatively evaluated using the SIGNAL-w (Stream Invertebrate Grade Number--Average Level-weighted) index. A morphological assessment of the stream structure was also carried out. Bioindication by SIGNAL reflected a very low water quality in the upper three sampled stream reaches, but with a significant improvement by the last site on the Rio Alamar, but only to a grade of critical to high pollution over a flowing distance of 29 kin. Levels of BOD and ammonium-N at the Rio Alamar (Toll Bridge) site remained quite high, 56 mg/L and 48 mg/L, respectively. Metal levels also ...

Related newspaper, magazine, and journal articles:

 
 
Newsweek Harper's Magazine The Washington Post Chicago Tribune Crain's Chicago Business PRNewswire Pediatric News The Nation Advertising Age The Economist (US) A FREE trial gives you access to over 80 million articles! Access over 6,500 publications with a FREE trial!