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Pesticide toxicity is often proposed as a contributing factor to the world-wide decline of amphibian populations. We assessed acute toxicity (48 h) of a glufosinate-based herbicide (Ignite 280 SL) and several glyphosate-based herbicide formulations (Roundup WeatherMAX, Roundup Weed and Grass Killer Super Concentrate, Roundup Weed and Grass Killer Ready-To-Use Plus on two species of amphibians housed on soil or moist paper towels. Survival of juvenile Great Plains toads (Bufo cognatus) and New Mexico spadefoots (Spea multiplicata) was reduced by exposure to Roundup Weed and Grass Killer Ready-To-Use Plus on both substrates. Great Plains toad survival was also reduced by exposure to Roundup Weed and Grass Killer Super...
Categories: Publication; Types: Citation
Playa wetlands are critical habitat for wildlife in the Southern High Plains (SHP), a region dominated by agriculture. Little information on pesticide levels exists for playas, and thus we measured organochlorine pesticide concentrations in sediment and amphibians collected from playas in cropland and grassland watersheds. Heptachlor, alpha- and beta-BHC, gamma-chlordane, and dieldrin were detected in sediment and/or tissue samples, typically at or below 1 ng/g, dry weight. However, mean DDT and DDE reached 19.7 and 4.1 ng/g in sediments and 6.3 and 2.4 ng/g in tissues, respectively. Land use did not influence pesticide levels in sediment or amphibians.
Categories: Publication; Types: Citation
Pesticides have been implicated in widespread amphibian declines. We assessed acute and chronic toxicity of two widely used herbicides to larval New Mexico (Spea multiplicata) and Plains (S. bombifrons) spadefoots from cropland and native grassland playas. Roundup WeatherMAX (WM) toxicity estimates (48- and 216-h LC(50); 48-h LC(1)) for both species were similar to environmental concentrations expected from accidental overspray. Chronic (30-day) exposure to WM at predicted environmental concentrations (2.0 and 2.8 mg glyphosate acid equivalents/L) reduced survival of both species. Ignite 280 SL (IG) toxicity estimates (48-h LC(50) and LC(1)) for both species were above predicted environmental concentrations of 1.0...
Categories: Publication; Types: Citation
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