Predation on meiofauna by juvenile spot Leiostomus xanthurus (Pisces) in contaminated sediments from Charleston Harbor, South Carolina, USA

Abstract

Meiofauna are a major food source for estuarine juvenile fish despite the fact that meiofauna often live in close contact with sediment-associated contaminants. Although there is laboratory evidence that fish feeding on contaminated meiofauna can build up significant contaminant body burdens, whether or not fish predation on meiofauna is affected by sediment contamination in the field has not been well established. To answer thls question, the number and taxa of meiobenthic prey items consumed by fish were compared between contaminated and uncontaminated habitats. A model predator, luvenile spot Leiostomus xanthurus (Pisces) was allowed to feed on natural meiobenthic communities in experimental sediment microcosn~s. Significantly more meiofauna were observed in the uncontaminated reference site (1060 nematodes per 10 cm2, 177 copepods per 10 cm2) than in the contaminated site (278 nematodes per 10 cm2. 97.5 copepods per 10 cm2). Although harpacticoid copepods were found in the foreguts of spot from both contaminated (mean 22.1 prey per fish) and uncontaminated (mean 13.7 prey per fish) sediments, there were few, if any, significant reductions in meiofauna abundance due to predation. There were differences between contaminated and uncontaminated sediments in taxa eaten by spot, but these differences were most likely due to differences between the meiofauna communities from the 2 sites, not differences in fish feeding behavior. Despite the potential adverse effects of eating meiofauna from contaminated sediments, juvenile spot do not avoid them.