Uptake of Hydrocarbons from Marine Sediments Contaminated with Prudhoe Bay Crude Oil: Influence of Feeding Type of Test Species and Availability of Polycyclic Aromatic Hydrocarbons

Abstract

Selected benthic animals were exposed to marine sediments contaminated with Prudhoe Bay crude oil, and uptake of hydrocarbons was monitored under various experimental schemes. When uptake of aliphatic and diaromatic hydrocarbons by two deposit feeders, Macoma inquinata and Phascolosoma agassizii, was compared with that of a suspension feeder, Protothaca staminea, we found that the deposit feeders generally accumulated hydrocarbons to a greater extent than the suspension feeder. However, other factors, such as the intrinsic capabilities of species to accumulate hydrocarbons, also played an important role in the extent of contamination. Hydrocarbon concentrations in the bivalve species (M. inquinata and P. staminea) increased during the 60-d exposure period; whereas concentrations in the sipunculid Phascolosoma agassizii appeared to have reached an equilibrium relatively early in the exposure. Experiments on uptake of 14C-phenanthrene, -chrysene, -dimethylbenz[a]anthracene, and -benzo[a]pyrene by M. inquinata indicated that compounds directly associated with sediment were less available for uptake than those released from sediment to the surrounding seawater. Concentration factors for uptake from sediment were ≤ 0.2, while those for uptake from seawater were 10–1349. Additionally, the heavier molecular weight aromatic compounds tended to be more concentrated in tissue and retained for longer periods of time than the lighter compounds. Key words: petroleum, hydrocarbons, sediments, bivalve, sipunculid, feeding type