Influence of dispersants on the bioavailability and trophic transfer of petroleum hydrocarbons to primary levels of a marine food chain

Use of chemical dispersants as oil spill clean-up agents, alters normal behavior of petroleum hydrocarbons (PH) by increasing functional water solubility. The bioavailable fraction may be increased through higher PH concentrations in the water column and altered interactions between dispersant, oil, and biological membranes. The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, [ 14C]naphthalene, were measured and compared for Prudhoe Bay crude oil (PBCO) dispersed with Corexit ® 9527 (DO) and undispersed preparations of the water-accommodated fraction (WAF) of PBCO. The model food chain consisted of Isochrysis galbana, a primary producer, and Brachionus plicatilis, a primary consumer. Direct aqueous (AQ) exposure was compared with combined aqueous and dietary (AQ and D) exposure. Results showed uptake of naphthalene by rotifers was not increased significantly ( P>0.05) in the presence of dispersant. A significant ( P