Use of Biological Endpoints in Flatfish to Establish Sediment Quality Criteria for Polyaromatic Hydrocarbon Residues and Assess Remediation Strategies

Chapter 1: Concentrations of serum/plasma estradiol, biliary fluorescent aromatic compounds (FACs), levels of hepatic CYP1A expression, and DNA damage were measured in sexually mature hornyhead turbot (Pleuronichthys verticalis) exposed in the laboratory for 7 days to a gradient of sediments collected from a natural petroleum seep in the Santa Barbara channel. Coal Oil Point (COP) sediments were homogenized and divided into 4 treatments containing 0% (sediment from the Orange County Sanitation District’s reference location), 33%, 66%, and 100% (COP) sediments. Sediment concentrations of twenty PAHs ranged from below the detection limit for the 0% COP sediment treatments to 105 μg/g in the 100% treatments with lower molecular weight compounds predominating. Concentrations of biliary FACs were not linear with COP treatment but levels of hepatic DNA damage increased linearly with increasing concentrations of high molecular weight PAHs. Hepatic CYP1A expression was elevated only in the 100% treatments. A reduction of plasma estradiol in male and female fish was observed in all COP exposures. These results demonstrate that acute sediment-only exposure of flatfish to naturallyderived PAHs elicits alterations in biochemical endpoints indicative of PAH bioavailability and adverse effects with different sensitivities. Use of Biological Endpoints in Flatfish to Establish Sediment Quality 3 Abstract Chapter 2: Coal Oil Point (COP) is a natural oil seep off the coast of Santa Barbara, California. Although most studies examining the fate and effects of petroleum have focused upon urbanized or anthropogenic sources of inputs, few have examined the effects of PAHs derived from natural seeps. In order to evaluate the effects of polyaromatic hydrocarbons (PAHs) derived from COP on marine fish populations, hatchery-reared California Halibut (Platichthys californicus) were exposed for 30 days to seven dilutions of sediments collected from COP. Hepatic cytochrome P450 1A (CYP1A), biliary fluorescent aromatic compounds (FACs), gonadal somatic indices, and plasma steroid concentrations. Sixteen USEPA priority PAHs were targeted fro analysis in each sediment dilution. In general, biochemical responses were somewhat recalcitrant to doseresponse relationships and were less sensitive than literature values established for the same indicators following exposure to urbanized PAHs. Trends toward reductions in plasma 17β−estradiol concentrations were observed, but reductions in gonadal somatic indices were not observed. FAC values for naphthalene, benzo(a)pyrene, phenanthrene-related compounds reached maximums at 33% COP sediment, but declined at higher concentrations. The resulting insensitivity may be unique for exposure to “natural” petroleum due to a higher concentration of lower molecular weight PAHs or uncharacterized inhibitors.