WP1 Sediment Quality Assessment
256 Portland Ballroom
1:20 PM - 4:40 PM, Tuesday
() Sediment toxicity associated with oil and/or brine spills in southern Illinois.
Orr, T1, Halbrook, R1, 1 Southern Illinois University, Carbondale, IL, USA
ABSTRACT- A triad approach was used to assess the sediment toxicity of oil and/or brine spills in intermittent streams in Illinois. Sediment and macroinvertebrate samples were collected in fall 2002 and spring 2003 from 30 streams exposed to oil and/or brine spills and 3 reference streams with no known oil or brine contamination. Chemical analyses were conducted for 14 polycyclic aromatic hydrocarbons, total petroleum hydrocarbons, and chloride. Sediment toxicity was evaluated with the amphipod Hyalella azteca. Benthic macroinvertebrate community structure was assessed with macroinvertebrate indices such as taxa richness, Ephemeroptera-Plecoptera-Tricoptera richness, and a family-level biotic index. Chemical analysis indicated that polycyclic aromatic hydrocarbons, total petroleum hydrocarbons, and chloride were generally present at negligible concentrations in sediment collected from study sites. One site exceeded the USEPA national water quality criterion for chloride in surface water (230 mg/l). Macroinvertebrate indices indicated that macroinvertebrate community structure was similar for both reference sites and correlated with physical habitat parameters rather than contaminant concentrations. Sediment toxicity tests with Hyalella azteca indicated that 2 sites were acutely toxic. However, contaminant concentrations were not elevated in sediments collected from this site. Growth was significantly lower for 5 sites after 42d indicated that these sediments may be chronically toxic. Decreased growth in these sites was not correlated with contaminant concentrations. Oil production in does not appear to be affecting sediment quality in southern Illinois.
Key words: Oil, Sediment quality triad, Brine, Macroinvertebrates