| 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. |
| Genre: | Article |
| ProdID: | 5224056 |
| Citation Author: | Sparling, D.W.; Fellers, G.M.; McConnell, L.L. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 1595 |
| Citation Issue: | 7 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Environmental Toxicology and Chemistry |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 5 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | 1591-1595 |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Pesticides and amphibian population declines in California, USA; 2001; Article; Journal; Environmental Toxicology and Chemistry; Sparling, D.W.; Fellers, G.M.; McConnell, L.L. |
| Citation Start Page: | 1591 |
| Citation Volume: | 20 |
| Citation Year: | 2001 |
| Type: | citation/reference |
| Text: | Pesticides and amphibian population declines in California, USA; 2001; Article; Journal; Environmental Toxicology and Chemistry; Sparling, D.W.; Fellers, G.M.; McConnell, L.L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://www3.interscience.wiley.com/journal/123194774/abstract |
| Date Other: | Wed, 16 Jun 2010 12:18 -0500 |
| Publisher: | |
