2006 BES Annual Meeting Presentation and Poster Abstracts
Biofilm vs. sediment: relative contributions to accumulation of trace elements in Rana sylvatica larvae
Co-Authors: Marjorie E. Wright, Casey Jackson, Valerie A. Schmidt, Joel W. Snodgrass, Ryan E. Casey
Abstract: Determining the relative contributions of different routes of exposure to trace element uptake in grazing aquatic organism is an important consideration when evaluating the risk of contaminated environmental media to those organisms. Biofilms growing on contaminated sediments may represent a distinct route of exposure as the biofilm itself may accumulate trace elements with differing availability for uptake than the contaminated sediment itself. In this experiment we used coal combustion waste (CCW) as a contaminated sediment to assess the relationship between route of exposure and the accumulation of trace elements in larval amphibians. In the laboratory we exposed wood frog (Rana sylvatica) larvae to four different treatments: clean algae, contaminated algae, clean algae with CCW slurry, and contaminated algae with CCW slurry to investigate the accumulation of trace elements as a consequence of sediment versus biofilm ingestion of CCW-derived trace elements. Contaminated algae was grown in the presence of CCW and as a result became enriched in Cr, Ni, As, Se, Sr, and Pb. Elevated tissue concentrations were noted for Cr, Ni, As, and Sr between both algae only treatments and the two CCW slurry treatments. A notable elevation of the elements As, Se, and Sr was seen from the clean algae treatments to the contaminated algae treatments without the CCW slurry. Our results suggest that both diet and sediment ingestion result in the accumulation of trace elements in aquatic anuran larvae, however ingestion of the inorganic sediment played a greater role than ingestion of biofilm in this system.