Importance of Sediment Working by the Deposit-Feeding Polychaete Arenicola marina on the Weathering Rate of Sediment-Bound Oil

Abstract

The interactions between the polychaete Arenicola marina, a common deposit feeder in sandy intertidal areas, and sediment contaminated with the fresh API (American Petroleum Institute) reference oils and weathered Bunker C oil remaining from the 1970 Arrow spill were investigated in laboratory experiments. Worms can tolerate low concentrations of sediment-bound oil, although the sediment working rate is reduced depending upon oil type, concentration, and degree of weathering. Hydrocarbon concentrations, measured gravimetrically and by gas chromatography and fluorescence spectroscopy, were substantially lower (17–72%) in worm casts than in initial sediment. This loss can be accounted for by microbial degradation, which is stimulated by the worms' activity, uptake of hydrocarbons into worms, and perhaps dissolution. A large population (10–25/m2) of Arenicola is present at Black Duck Cove, N.S., living in sediment contaminated with weathered Bunker C oil remaining from the Arrow spill. These worms, which have spent their entire lives in oil-polluted sediment, do not have markedly elevated hydrocarbon concentrations and behaved no differently in experiments than worms collected from a clean environment. Calculations suggest that they are capable of removing the oil present in a square metre of sediment in 2–4 yr. After any oil spill, when concentrations reach tolerable levels, activities of deposit-feeding animals such as Arenicola can apparently accelerate the weathering rate of sediment-bound oil. Key words: sediment, Arenicola marina, polychaete, petroleum, weathering rate, pollution, hydrocarbon

Cytochemical responses of Hediste diversicolor (Nereidae, Polychaete) sampled from polluted sites along the Tunisian coast

“…Apparently much of the naphtalene remained bound to the sediments as it passed through the gut of the worm and any that was taken up by the worm was quickly released. This reduced uptake is in agreement with earlier work by Gordon et al (1978) who found little evidence of uptake of PAHs in the same species collected from an area directly impacted by an oil spill in Canada. Weston et al (2004) demonstrated that the initial uptake of benzo(a)pyrene (BaP) by Abarenicola pacifica (Family Arenicolidae) was due to absorption of dissolved BaP across the body wall but after several days of exposure the main source of uptake was from ingested material.…”

The in vitro influence of the burrowing polychaete Nereis diversicolor on the fate of petroleum hydrocarbons in marine sediments

“…Table I presents After 45 days, differences between "clean" and contaminated sediments were about 54 %, and could only be seen below 6-cm depth. Research has already shown that the 5-day sediment reworking rate of Arenicola marina was about 70 % reduced in presence of a surface sediment oil concentration of 2086 mg. kg-1 dry sediment 24 , and when natural populations were sprayed with oil 25 at a rate of 0.2 l. m -2 .…”

Effects of the polychaetes Nereis diversicolor and Arenicola marina on the fate and distribution of pyrene in sediments

“…The presence of biota, especially sediment-dwelling animals, also likely play an important role in the fate of PAHs in sediment. Sedimentdwelling animals are known to affect the release and distribution of hydrophobic organic compounds associated with the sediment through their bioturbating activities, particle mixing and irrigation (Gordon et al 1978, Schaffner et al 1997. Bioturbation leads to both continuous sediment mixing and the repeated transport of particulate material from deeper sediment layers to the surface and vice versa.…”