PAH effects on removal of meiobenthic copepods by juvenile spot (Leiostomus xanthurus: Pisces)

Juvenile spot, Leiostomus xanthurus, 20–35 mm SL, feed by taking small mouthfuls of sediment; preferentially they feed on muddy estuarine sediments, and consume harpacticoid copepods over other prey. This study tested the difference in copepod removal by juvenile spot feeding in sediments spiked with PAHs (polycyclic aromatic hydrocarbons) at recorded, measured field levels vs uncontaminated sediments. Into 2 l of sediment and seawater glass microcosms (some uncontaminated, some contaminated), 300–700 copepods and two juvenile spot were added; the spot were allowed to feed for 4 h. Copepod removal was significant in all microcosms, and there was a statistically significant difference between copepod removal in PAH-contaminated vs uncontaminated sediments. The difference was small and probably not energetically important to the spot. Conducting the experiments in contaminant levels recorded from the field provides a baseline for making hazard assessments in environments where contaminant spills or discharge have occurred.