MA9 Hazard Assessments for Near Coastal Ecosystems
D137-140
8:00 AM - 12:00 PM, Monday
() Relationship of water quality characteristics, solar radiation, and photoinduced toxicity of PAHs in Prince William Sound, Alaska.
Oris, J1, Stubblefield, W2, Smith, C2, Maki, A3, 1 Miami University, Oxford, OH, USA2 Parametrix, Corvallis, OR, USA3 Exxon Mobil
ABSTRACT- The photo-induced toxicity of polycyclic aromatic hydrocarbons (PAHs) is determined by both the tissue concentrations of PAHs and the concomitant exposure to actinic solar radiation. In remote areas that may be subject to elevated PAH exposures, predictive models (e.g. SBDART) have been the only means for estimating solar radiation dose, and these typically do not consider the potential mitigating effects of water quality characteristics on light penetration and organism exposure. Studies were conducted to determine the influence of water quality characteristics on the penetration of solar radiation into waters of Prince William Sound, AK, and their effect on the photoinduced toxicity of PAHs on larval fish. Ambient light intensities and penetration coefficients were collected over a 5 month period May-Sept) in a variety of locations including Knight Island, Montague Island, and LaTouche Island. Water was collected from nearshore and offshore areas and analyzed for standard water quality parameters that might affect light penetration. Water was also collected from areas known to have been oiled as a result of the Exxon Valdez spill in 1989 and tested in the laboratory for ambient phototoxicity using larval Pacific Herring. Differences among sites and seasonal changes in penetration coefficients correlated with water quality characteristics. Although empirically shown to be sensitive to PAH-induced phototoxicity under both laboratory and field conditions, no ambient phototoxicity was observed with larval herring exposed to water samples collected from areas of known oil contamination in the Sound.
Key words: UV, Solar Radiation, Prince William Sound, Phototoxicity