Publication Abstract

Potential for UV-light to alter the toxicity of environmental seawater

B.P. Lyons, F. Goodsir, J.E. Thain, J. Wedderburn and I.R.B. McFadzen

There is a growing body of evidence to suggest that certain polycyclic aromatic hydrocarbons (PAHs) pose a greater hazard to aquatic organisms than previously demonstrated, due to their potential to cause photo-induced toxicity (phototoxicity) when exposed to ultraviolet (UV) light. Here we present data from a study investigating the potential for UV light to enhance or mitigate the toxicity of environmental water samples (sub-surface water and sea surface micro-layer samples) collected as part of the 2001 BECPELAG ICES/IOC sea-going workshop. In order to achieve this we employed the oyster embryo (Crassostrea gigas) bioassay and tested environmental samples under both traditional testing protocols omitting UV light and under conditions simulating natural sunlight (approximately 10% ambient UV light intensity, UVB = 3.8 - 6.3 µW/cm2 and UVA= 280 - 456 µW/cm2). No evidence of phototoxicity was detected in any of the subsurface waters samples assayed, while one of the seven sea surface micro-layer samples (Statfjord) displayed enhanced toxicity under UV lighting. These results suggest that conventional aquatic toxicity testing procedures can lack environmental realism and UV light may need to be incorporated into some standard laboratory tests before any realistic assessment of toxicity in the aquatic environment can be made.

Reference:

B.P. Lyons, F. Goodsir, J.E. Thain, J. Wedderburn and I.R.B. McFadzen, 2002. Potential for UV-light to alter the toxicity of environmental seawater. ICES Copenhagen, CM2002/X:08, 13pp