Meeting Abstract

P1.20  Wednesday, Jan. 4  Metal Accumulation from Dietary Exposure in the Sea Urchin, Strongylocentrotus droebachiensis HARPER, B.T.*; JARVIS, T.A.; BUTLER, B.; RICE, L.; RYAN, S.; BIELMYER, G.K.; Valdosta State University; Valdosta State University; Valdosta State University; Valdosta State University; Waterford Institute of Technology; Valdosta State University btharper@valdosta.edu

Heavy metal contamination is an increasing problem in aquatic environments, mainly due to anthropogenic inputs. Environmental regulations are developed using toxicity data of waterborne metal exposures and less research has focused on dietary metal exposure. However, recently the importance of the dietary exposure route has been demonstrated, particularly in assessing sub-lethal toxicity in invertebrates. This research investigated the accumulation and effects of dietary metals in a macro invertebrate. The seaweed species Ulva lactuca and Enteromorpha prolifera readily uptake metals, are widely distributed, and are often used as bioindicators of pollution in ecological studies. Additionally, these species serve as vital components in aquatic food chains. U. lactuca and E. prolifera were concurrently exposed to five metals (Cu, Ni, Pb, Cd, and Zn) and then fed to the sea urchin Strongylocentrotus droebachiensis for a period of two weeks. Body mass, test length, and total length were measured, the sea urchins were dissected and their organs (esophagus, stomach, intestine, gonads, and rectum) were digested and analyzed for metals. The results demonstrated that metal accumulation varied between seaweed species and among metals. All of the metals accumulated within at least one organ of S. droebachiensis, with Cu being most significant. In general, there were higher levels of metals within the sea urchins fed E. prolifera as compared to those fed U. lactuca. These results indicate that E. prolifera may accumulate metals in a more bioavailable form than within U. lactuca. In this study no significant differences in body length, growth, or coelomic fluid ion concentration were detected.