Journal or Publishing Institution: Archives of Environmental Contamination and Toxicology
Study: https://www.ncbi.nlm.nih.gov/pubmed/19768486
Author(s): Williams, B.K. and Semlitsch, R.D.
Article Type: Peer Reviewed Study
Record ID: 1241
Abstract: Low levels of agricultural herbicides often contaminate surface water and might persist throughout the growing season, potentially acting as stressors on aquatic organisms. Although low-dose, chronic exposures to agrochemicals are likely common for many nontarget organisms, studies addressing these effects using end-use herbicide formulations are rare. We exposed three common species of tadpoles to conservative levels of atrazine, S-metolachlor, and glyphosate end-use herbicide formulations throughout the larval period to test for survival differences or life-history trait alterations. Exposure to the glyphosate product Roundup WeatherMax at 572 ppb glyphosate acid equivalents (a.e.) resulted in 80% mortality of western chorus frog tadpoles, likely as a result of a unique surfactant formulation. Exposure to WeatherMax or Roundup Original Max at 572 ppb a.e. also lengthened the larval period for American toads. Chronic atrazine and S-metolachlor exposures induced no significant negative effects on survival, mass at metamorphosis, or larval period length at the levels tested. These results highlight the importance of explicitly tying chronic tests to the natural environment and considering contributions of surfactant/adjuvant components to end-use formulation toxicities, even between very similar products.
Keywords: Atrazine, Glyphosate, Larval Period, Metolachlor, American Toad, frogs, biological development, glyphosate, herbicides, metamorphosis, metolachlor, mortality, nontarget effects, nontarget organisms, survival, toxicity, death rate, non-target organisms, non-target species, nontarget species, weedicides, weedkillers, Anura, Amphibia, vertebrates, Chordata, animals, eukaryotes
Citation: Williams, B.K. and Semlitsch, R.D., 2010. Larval responses of three Midwestern anurans to chronic, low-dose exposures of four herbicides. Archives of Environmental Contamination and Toxicology, 58(3), pp.819-827.
