Genomic and Physiological Footprint of the Deepwater Horizon Oil Spill on Resident Marsh Fishes
When the well beneath BP’s Deepwater Horizon rig blew out in 2010, 4.9 million barrels of oil poured into the waters of the Gulf of Mexico. Despite the massive clean-up effort, significant quantities of oil made their way to into region’s coastal ecosystems.
A 2011 study published for the Proceedings of the National Academy of Sciences (PNAS), “Genomic and Physiological Footprint of the Deepwater Horizon Oil Spill on Resident Marsh Fishes,” sampled tissues from adult Gulf killifish in Louisiana’s marshes throughout the first four months of the spill to track the oil’s effects on the ecosystem.
The study’s results include:
- While sampled water and tissues didn’t show abnormally high levels of oil, there was genetic evidence of polycyclic aromatic hydrocarbons (PAH) exposure, which can lead to cardiovascular failure in fish. While no such diseases were found in the analyzed embryos, the researchers point out that even at this level of intoxication, the embryonic killifish are at risk in adulthood.
- Through genetic analysis, researchers determined that killifish had sustained “persistent exposure to sub-lethal concentrations of crude oil components consistent with negative population-level impacts in fish, sea otters, and harlequin ducks following the Exxon Valdez oil spill.”
- Ion transport genes allow killifish to tolerate varying salinity levels of coastal waters; fish at the sample sites showed changes in multiple ion-transport genes, potentially reducing their ability to “adjust physiologically to natural stressors.”
- Evidence of oil exposure was shown by several gene ontology (GO) categories that play a role in DNA repair, immune response, and reproduction.
“Although body burdens of toxins are not high, consistent with reports indicating that seafood from the Gulf of Mexico is safe for consumption, this does not mean that negative biological impacts are absent,” the researchers write. They recommend that future research look at the long-term impact of “high concentrations of hydrocarbons in sediments [that] may provide a persistent source of exposures to organisms resident in Louisiana marshes.”
Note to instructor: The suggested assignments are designed for flexibility. They can be used in whole or part and can be adapted to a particular task -- for example, the newswriting assignments could be applied to the writing of the headline, the lead, the nut graph or the full story. Material from the assignments could also be combined with other material, for example, in the writing of a background, feature or local-angle story.
- Summarize the study in fewer than 40 words.
- Express the study's key term(s) in language a lay audience can understand.
- Evaluate the study's limitations. (For example: Do the results conflict with those of other reliable studies? Are there weaknesses in the study's data or research design?)
Read the study-related New York Times article titled "Oil Spill Affected Gulf Fish’s Cell Function, Study Finds."
- Reporter's use of the study: Evaluate what the reporter chose to include and exclude from the study. Would the audience have acquired a clear understanding of the study's findings and limits from this article?
- Reporter's use of other material: Assess the material in the article that is not derived from the study. For example, does the reporter place the study in the context of other research and to what effect? Does the reporter include reactions to the study from other researchers or interested parties (e.g., political groups business leaders, or community members) and are their credentials or possible biases made clear?
- Write a lead (or headline or nut graph) based on the study.
- Spend 60 minutes exploring the issue by accessing sources of information other than the study. Write a lead (or headline or nut graph) based on the study but informed by the new information. Does the new information significantly change what one would write based on the study alone?
- Interview two sources with a stake in or knowledge of the issue. Be prepared to provide them with a short summary of the study in order to get their response to it. Write a 400-word article about the study incorporating material from the interviews.
- Spend additional time exploring the issue and then write a 1,200-word background article, focusing on major aspects of the issue.