Bioaccumulation, growth and larval settlement effects of sediment-associated polynuclear aromatic hydrocarbons on the estuarine polychaete, Streblospio benedicti (Webster)

Macrobenthos of the pristine North Inlet, SC, USA and urbanized Murrell's Inlet, SC, estuaries are predominated by the cosmopolitan spionid polychaete Streblospio benedicti. (Webster) Laboratory experiments were conducted to measure larval settlement and metamorphosis, and sub-adult bioaccumulation/growth rates of S. benedicti when exposed to controlled concentrations of sediment-associated polynuclear aromatic hydrocarbons. Larval settlement/metamorphosis was reduced, but not significantly affected (relative to controls) by 1X, 5X and 10X background PAH mixture concentrations of the six most abundant sediment-associated PAHs found in urbanized Murrell's Inlet (1X = 0.9 mu g PAH per g dry sediment). Bioaccumulation of the most abundant sediment-associated PAH, fluoranthene (FL), was very high in this PAH tolerant species-9.5-13.7X FL sediment concentrations after 28-day exposures. 28-day exposures to 0.26 and 2.4 mu g FL.g(-1) caused no significant mortality, and significantly effected positive average weight gains in S. benedicti up to 18 days exposure. However, dramatic and significant weight declines occurred from days 18-28 in both FL treatments. Such a strong tolerance of PAH may explain why these polychaetes are not limited to pristine geographic areas, but can, as numerous field studies have shown, recruit well into hydrocarbon-contaminated and organically enriched sediments. (C) 1997 Elsevier Science B.V.