HIGHLIGHTS
- Abt investigated the photo-induced toxicity of crude oil from Australia’s North West Shelf
- We also investigated the apparent toxicity of specific photo-products.
- Exposure to NWS oil and UV results in photo-induced toxicity in both species tested.
The Challenge
Photo-induced toxicity of crude oil occurs when ultraviolet light (UV) contacts certain photo-active polycyclic aromatic hydrocarbons (PAHs), which act as catalysts and produce reactive oxygen species. When this reaction occurs in the tissues of transparent organisms the ROS production causes cell/tissue damage and results in acute mortality. There are at least 14 photo-active PAHs in crude oil. Our recent work on the toxicity of Deepwater Horizon oil indicates that photo-activation increases toxicity by 10 to 100 times.
Abt Global – in collaboration with colleagues at Australia’s Commonwealth Scientific and Industrial Research Organisation and the University of North Texas – conducted several bioassays, or toxicity experiments, at the Indian Ocean Marine Research Centre in Perth, Western Australia.
The Approach
We investigated the photo-induced toxicity of crude oil from Australia’s North West Shelf (NWS) to embryos and larvae of indigenous yellowtail amberjack (Seriola lalandi) and black bream (Acanthopagrus butcheri). In addition to investigating photo-induced toxicity as a result of PAH activation in the tissues of these fish, we also investigated the apparent toxicity of photo-products that are produced in the water when UV light contacts PAHs in water-accommodated fractions (WAFs) generated using NWS oil.
The Results
Results demonstrate that exposure to NWS oil and UV results in photo-induced toxicity in both species tested. Additionally, UV exposure of WAFs produced using NWS oil generates toxic photo-products that increase the toxicity of these WAFs to our test species when they are exposed to the mixture in the absence of UV.