Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Pesticides and amphibian population declines in California, USA

Pesticides and amphibian population declines in California, USA Several species of anuran amphibians have undergone drastic population declines in the western United States over the last 10 to 15 years. In California, the most severe declines are in the Sierra Mountains east of the Central Valley and downwind of the intensely agricultural San Joaquin Valley. In contrast, coastal and more northern populations across from the less agrarian Sacramento Valley are stable or declining less precipitously. In this article, we provide evidence that pesticides are instrumental in declines of these species. Using Hyla regilla as a sentinel species, we found that cholinesterase (ChE) activity in tadpoles was depressed in mountainous areas east of the Central Valley compared with sites along the coast or north of the Valley. Cholinesterase was also lower in areas where ranid population status was poor or moderate compared with areas with good ranid status. Up to 50% of the sampled population in areas with reduced ChE had detectable organophosphorus residues, with concentrations as high as 190 ppb wet weight. In addition, up to 86% of some populations had measurable endosulfan concentrations and 40% had detectable 4,4′‐dichlorodiphenyldichloroethylene, 4,4′‐DDT, and 2,4′‐DDT residues. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Environmental Toxicology & Chemistry Wiley

Pesticides and amphibian population declines in California, USA

Download PDF
5 pages

Loading next page...
 
/lp/wiley/pesticides-and-amphibian-population-declines-in-california-usa-fDmRsjopPV

References (42)

Publisher
Wiley
Copyright
Copyright © 2001 SETAC
ISSN
0730-7268
eISSN
1552-8618
DOI
10.1002/etc.5620200725
Publisher site
See Article on Publisher Site

Abstract

Several species of anuran amphibians have undergone drastic population declines in the western United States over the last 10 to 15 years. In California, the most severe declines are in the Sierra Mountains east of the Central Valley and downwind of the intensely agricultural San Joaquin Valley. In contrast, coastal and more northern populations across from the less agrarian Sacramento Valley are stable or declining less precipitously. In this article, we provide evidence that pesticides are instrumental in declines of these species. Using Hyla regilla as a sentinel species, we found that cholinesterase (ChE) activity in tadpoles was depressed in mountainous areas east of the Central Valley compared with sites along the coast or north of the Valley. Cholinesterase was also lower in areas where ranid population status was poor or moderate compared with areas with good ranid status. Up to 50% of the sampled population in areas with reduced ChE had detectable organophosphorus residues, with concentrations as high as 190 ppb wet weight. In addition, up to 86% of some populations had measurable endosulfan concentrations and 40% had detectable 4,4′‐dichlorodiphenyldichloroethylene, 4,4′‐DDT, and 2,4′‐DDT residues.

Journal

Environmental Toxicology & Chemistry – Wiley

Published: Jul 1, 2001

There are no references for this article.