PARENT SESSION
MP9 - Solar Radiation Influence on Aquatic Toxicity Processes
Chair: Oris, Jim1, 1 Miami University, Oxford, OH
Co-chair: Lavvorn, Marj2, 2
2:10 PM to 5:30 PM - Monday, 18 November 2002
Room Ballroom E
(316) Is PAH phototoxicity an ecologically irrelevant phenomenon?
Chapman, Peter*,1, McDonald, Blair1, 1 EVS Environmental Consultants, North Vancouver, B.C., Canada
ABSTRACT- Photo-enhanced toxicity of polycyclic aromatic hydrocarbons (PAH) is well demonstrated in laboratory and in a few in situ studies. Effects have been observed for multiple taxa and toxicological endpoints, and the mechanism of toxic action has been described. However, this phenomenon is ameliorated by physical, chemical and biotic factors; "the unanswered question...into the phototoxicity of contaminated sediment [and water] is whether phototoxicity is of ecological relevance or merely an interesting laboratory artifact" (Boese et al., 1999). To date there have been no studies that clearly and directly implicate PAH phototoxicity with adverse ecological effects in field populations. If phototoxic effects were present in natural environments at the same magnitude as those observed in published studies, large areas of shallow aquatic environments should be depauperate; yet this is not the case. We have worked at sites where phototoxicity was demonstrated for particular organisms, yet these same organisms remained abundant at those sites. Determination of the ecological relevance or lack thereof of PAH phototoxicity should supplant continued publication of ecologically irrelevant laboratory studies. Environmental management decisions should not, without a determination of ecological relevance, include laboratory-based phototoxicity studies.
Key words: PAH, phototoxicity, sediments, aquatic