Beef cattle feedlot surface water containing multi-class agrochemicals elicits physiological and behavioral responses among Daphnia pulex.

Despite increasing public concern about air and water pollution risks posed by concentrated animal feeding operation areas (CAFOs), there is little information about bioavailability and ecosystem impacts of agrochemicals used to increase productivity. In this study, we investigated the toxicity of wastewaters originating from beef cattle feeding operation on Daphnia pulex. Specifically, we assessed lethal and chronic sublethal exposure effects using various endpoints including survival, oxygen consumption, morphology, reproduction, and swimming behavior. Exposure assessments (acute and chronic) were performed with ten (10) surface water samples collected from on-site retention ponds designated as A, B, C, D, E, F, G, H, I, and R (reference site). Surface water samples were diluted to yield five concentrations (stock, 1 × , 2 × , 3 × , and 4 ×) as treatments and deionized water was used as control. Results showed site-specific and concentration-related effects on toxicity endpoints. Among treatments, significant (p < 0.05) increase in mortality rate (for A, E, F, and H) and decreasing total body length and width (for B, C, D, and G) of D. pulex were observed with increasing wastewater concentration. However, treatments did not have significant effect on swimming behavior (average speed) after exposure to the wastewater samples from all sites except for site E. Evidence from this study suggested that surface waters near beef cattle feed yards affected physiological responses in D. pulex and therefore may similarly affect organisms in the surrounding aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Monitoring & Assessment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)