Gulf of Mexico

What are we studying? | Why are we studying? | What are we finding? | What does it mean? | Where can I read more?

What are we studying?

The Gulf of Mexico is located off of the coasts of Florida, Alabama, Mississippi, Louisiana, Texas and Mexico. It is a primary habitat for several marine species including sperm whales and Bryde’s whales. We are studying each of these whale species as well as pilot whales, which are a visiting species (not year round) in the Gulf of Mexico. Our Gulf of Mexico Offshore Toxicology Study investigates the impact of the Deep Water Horizon oil crisis on whales and humans. This study is a blend of research work at sea and in the laboratory and seeks to understand the impact of this crisis on wildlife in the Gulf of Mexico and the people who depend on it.

Why are we studying it?

On April 20, 2010, the Deepwater Horizon oil rig exploded resulting in an uncontrolled release of crude oil into the ocean. By the time the well was capped and the oil flow stopped, the disaster had become the largest environmental oil crisis in U.S. history and the second largest in world history. Superimposed on the massive oil release, was the use of chemical dispersants that were sprayed on top of the oil and injected into the Gulf waters in unprecedented quantities. The toxicity of these dispersants is unknown, and it is uncertain how mixing them with oil might alter the toxicity of the oil. We have shown that these dispersants do indeed induce cytotoxic effects and DNA damage. Early reports suggest the dispersants make the oil much more toxic.

This crisis provides a unique and critical opportunity to understand the impact of ocean pollution on marine life. The data collected and the lessons learned will serve to inform us about the decisions made and the actions taken in the Gulf of Mexico, which will then, in turn, serve to inform us how to move forward in improving conditions in the Gulf of Mexico as well as inform us better on how to protect other important marine environments from this sort of disaster.

 

What are we finding?

We tested samples of oil and tarballs from the Gulf of Mexico Oil Spill and found high levels of the toxic metals, chromium and nickel. In addition, we found that levels of chromium and nickel in sperm whale biopsies collected in the months following the oil spill were also high; significantly higher than levels collected from other areas of the world. We have also found that both particulate and soluble forms of chromium (VI) induced cell death and damaged chromosomes in sperm whale skin and lung cells. These outcomes support the possibility that chromium may cause reproductive and developmental issues in the whales and may cause whale lung cancer.

We also found that chemical dispersants can cause cell death and damage chromosomes in sperm whale cells. These findings suggest that dispersant exposure may pose a health risk for whales.

 

What does it mean?

Our data indicate that metals are an important concern in the Gulf of Mexico oil crisis. Our data support the suggestion that chromium (VI) poses a potential health risk to whales who are exposed to it through either inhalation of chromium (VI) or other routes such as diet. Furthermore, because our data indicate that chromium (VI) damages chromosomes, chromium (VI) exposure may contribute to the development of cancer, developmental abnormalities and failure to reproduce. In addition, our data suggest that dispersant exposure may pose a health risk for whales.

 

Where can I read more?

• Wise, Sr., J.P., Payne, R., Wise, S.S., LaCerte, C., Wise, J., Gianios, Jr., C., Thompson, W.D., Perkins, C., Zheng, T., Zhu, C., Benedict, L. and Kerr, I. A Global Assessment of Chromium Pollution using Sperm Whales (Physeter macrocephalus) as an Indicator Species. Chemosphere, 75: 1461–1467, 2009. PMID: 19324391.

• Wise, Sr., J.P., Wise, S.S., LaCerte, C., Wise, Jr., J.P., and Aboueissa, A. The Genotoxicity of Particulate and Soluble Chromate in Sperm Whale (Physeter macrocephalus) Skin Fibroblasts. Environmental and Molecular Mutagenesis, 52: 43-49, 2011. PMID: 20839228.

• Wise, C.F., Wise, Jr., J.P., Wise, S.S. and Wise, Sr., J.P. Skin Biopsy Applications in Free Ranging Marine Mammals: A Case Study of Whale Skin Biopsies as a Valuable and Essential Tool for Studying Marine Mammal Toxicology and Conservation. Chapter 5, pp. 109-122 in Romero, A. and Keith, E.O. (eds.) New Approaches to the Study of Marine Mammals. InTech, Rijeka, Croatia. 2012.

• Wise, J. and Wise, Sr., J.P. A Review of the Toxicity of Chemical Dispersants. Reviews on Environmental Health, 26(4): 281-300, 2011. PMID: 22435326.

• Li Chen, T., LaCerte, C., Wise, S.S., Holmes, A., Martino, J., Wise, Jr., J.P., Thompson, W.D. and Wise, Sr., J.P. Comparative Cytotoxicity and Genotoxicity of Particulate and Soluble Hexavalent Chromium in Human and Sperm Whale (Physeter macrocephalus) Skin Cells. Comparative Biochemistry and Physiology – Part C: Toxicology & Pharmacology, 155: 143–150, 2012. PMID: 21466859. PMCID: PMC4084666.

• Wise, Jr., J.P., Wise, J., Wise, C.F., Wise, S.S., Gianios, Jr., C., Xie, H., Thompson, W.D., Perkins, C. Falank, C. and Wise, Sr., J.P. Concentrations of the Genotoxic Metals, Chromium and Nickel, in Whales, Tarballs, Oil Slicks and Released Oil from the Gulf of Mexico in the Immediate Aftermath of the Deepwater Horizon Oil Crisis: Is Genotoxic Metal Exposure Part of the Deepwater Horizon Legacy? Environmental Science and Technology, 48(5): 2997–3006 2014. PMID: 24552566. PMCID: PMC3983321.

• Wise, C.F., Wise, J.T.F., Wise, S.S., Thompson, W.D., Wise, Jr., J.P. Wise, Sr., J.P. Chemical Dispersants used in the Gulf of Mexico Oil Crisis Are Cytotoxic and Genotoxic to Sperm Whale Skin Cells. Aquatic Toxicology, 152: 335–340, 2014. PMID: 24813266.