BIOAVAILABILITY OF SEDIMENT-SORBED NAPHTHALENES TO THE SIPUNCULID WORM, Phascolosoma agassizii

Abstract The peanut worm (Sipunculida: Phascolosoma agassizii ) was exposed to petroleum hydrocarbons from Prudhoe Bay crude (PBC) oil. Uptake and release of naphthalene and alkylnaphthalenes were compared for worms exposed to hydrocarbons in solution, oil on the surface of sediments and oil mixed in sediment. Spiunculids exposed for 24 hr to a water-soluble fraction of PBC contained from 2 to 10 times the concentration of naphthalenes initially in the water. After living for two weeks in sediment, either oiled on the surface or mixed thoroughly with oil, animals contained from 2 to 4 ppm of total naphthalenes. The tissue content of hydrocarbons in organisms exposed to sediment-bound hydrocarbons compared closely with hydrocarbon content of the oil-contaminated sediments and may therefore represent contaminated sediment within the gut. Depuration of naphthalenes was rapid when worms were transferred to clean water and/or sediment, perhaps indicating egestion. After two weeks of depuration, both water-and sediment-exposed worms released naphthalenes to background levels. From these results it does not appear that significant bioaccumulation of naphthalenes occurs from hydrocarbon fractions bound to sediment.