BIOAVAILABILITY OF PETROLEUM HYDROCARBONS FROM WATER, SEDIMENTS, AND DETRITUS TO THE MARINE ANNELID, NEANTHES ARENACEODENTATA

Abstract

ABSTRACT Uptake, retention, metabolism, and depuration of diaromatic hydrocarbons by the polychaete, Neanthes arenaceodentata, were examined in experiments utilizing seawater solutions and sediments contaminated with either No. 2 fuel oil water-soluble fractions or radio-labelled naphthalenes. Polychaetes rapidly accumulate 14C-naphthalene (magnification factor = 40X) from solution during short-term exposure (24 hr). Worms slowly released hydrocarbons accumulated during acute exposure down to undetectable levels (<0.05 ppm) within 300 hours after return to clean seawater. 14C-naphthalene accumulated from solution was metabolized by polychaetes, and associated microflora apparently play no role in uptake, release, or metabolism. Analyses of worms held for 28 days in clay-silt sediments artificially contaminated with No. 2 fuel oil (9 μg total naphthalenes/g wet sediment) indicate that naphthalenes were not accumulated by worms at tissue concentrations above 0.1 ppm. Polychaetes likewise failed to accumulate 14C-methylnaphthalene from ingestion of contaminated detritus (10-15 μg 14C-methylnaphthalene/g dry detritus) for 16 consecutive days. These data suggest that petroleum hydrocarbons bound to sediment particles or particulate organic matter are less available to marine worms than those in solution.