Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/1995
Publication Date: N/A
Technical Abstract: "Temporary" ponds have been created by using drop pipes as a means of reducing erosional cutting in agricultural fields. A toxicological evaluation of these pond habitats was conducted using two assays to assess toxicity of sediment pore water and whole sediment. Sediments were collected and tested during the summer and fall seasons. The Microtox Comparison Test* was used initially to determine relative toxicities of pore water from 10 field test sites. The initial screening was using to elucidate the relative toxicity of samples from the field test sites as compared to an uncontaminated reference site. The summer sampling period included the screening of ten test sites. One site exhibited significant inhibition compared to the uncontaminated reference site, suggesting a toxic response. The remaining nine sites exhibited less than 30% relative inhibition, indicating minimal toxicity. The fall sampling period consisted of four test sites, exhibiting less than 50% relative inhibition. A *Hyalella azteca* ten-day sediment bioassay was used to assess toxicity in sediments from four selected sites using survival and growth as toxicological endpoints. Statistically significant differences in survival were not detected among the sites for either testing period. One site, from the summer sampling period has statistically significant decreased growth when compared to the control and two other field test sites for either testing period. There were no significant differences in growth among test sites during the fall sampling period. Results from the toxicological evaluation, along with extensive ecological evaluations, will be used to assess the best approach for implementation of temporary pond habitats with existing agricultural practices.