In 2010 the RV Odyssey headed to the Gulf of Mexico with a team from Ocean Alliance and our partners at the Wise Laboratory of Environmental and Genetic Toxicology at the University of Southern Maine. The Deepwater Horizon well had been capped, but the Gulf wildlife and people were now challenged with coping with the oil and dispersants that remained. Our specific concern was the potential effects of this disaster on the population of sperm whales living in the Gulf in the deep water where the disaster occurred, and having sampled hundreds of sperm whales around the world during the Voyage of the Odyssey 2000-2005 we were well-equipped and trained to track and sample sperm whales in the Gulf. Our global data set gave us a unique opportunity to put what we found in the Gulf into a global context. We’ve been back every year since the disaster and this week those expeditions have produced a new study.
The Wise Laboratory has published the first paper on the toxicity of chemical dispersants in whales. The study, published in the journal Aquatic Toxicology, is titled Chemical dispersants used in the Gulf of Mexico oil crisis are cytotoxic and genotoxic to sperm whale cells.
If something is cytotoxic it kills cells; if it is genotoxic the cells live but their DNA is damaged. DNA damage is well-recognized as a potential precursor to cancer, so chemicals that are both cytotoxic and genotoxic are clearly not a good thing–particularly, as in this case, when you have damage at low doses. Toxicologists believe that everything is toxic–what is important is the dose.
When Roger Payne first founded Ocean Alliance in 1971 he called it The Long-Term Research Institute. Roger felt that you had to study populations over time if you really wanted to understand the threats to these populations. Ocean Alliance is typically less concerned by the immediate effect of a chemical exposure event such as the Deepwater Horizon Disaster on whales than with the chronic effects (low dose exposure to environmental toxicants over time). The effects of the Exxon Valdez disaster are still being felt 25 years later. The Wise lab paper speaks exactly to this concern.