Anna Parker, Duke University

Class Year:

Mentor:

Abstract:

The potential for ecological impacts, due to additional suspended sediment introduced to the water column, as a result of agriculture and construction, have become more widely recognized in recent years. However, the possible effects of increasing levels of suspended sediment on the general health and reproduction of copepods, a major food source for larval and commercial fishes are not well understood. In this study Acartia tonsa were added to l-L jars containing 0.5 ppm Thalassiosira weissflogii and varying levels of commercially available Kaolin corresponding to suspended sediment levels of 0, 49.5, 147.5, and 382 mg/L. The females were allowed to reproduce for 24hr, at which time the contents of the jars were screened and preserved for counting. Each sediment concentration was tested in quadruplicate. Results varied between trials. In the first trial, egg and nauplii production showed a significant decrease with the addition of sediment. In the second trial there was virtually no difference in reproduction at low levels of sediment, with a significant increase at the highest level. Possible explanations and implications for these results will be discussed.