How are animals coping five years after the Deepwater Horizon oil spill in the Gulf of Mexico?
Animals vs. oil spills. I’m Bob Hirshon and this is Science Update.
Five years ago, the Deepwater Horizon oil rig exploded in the Gulf of Mexico, causing the largest marine oil spill in U.S. history. Since then, scientists have been studying the impact of the toxic oil on sea life. Warren Cornwall reports in Science magazine that some animals show more resilience than others.
Dolphins aren’t doing so well according to the latest health checkups.
They have high rates of lung disease and suppressed hormones, both signatures of toxic exposure.
The scientists found that 17% of the dolphins were in such bad shape that they didn’t expect them to live long.
But the fish tell a different story. They also show signs of toxic exposure, including overactive immune systems and gill damage.
You would think that that would translate into an overall impact on the fish populations, but so far the scientists haven’t found that. So that’s a puzzle.
I’m Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
British Petroleum’s Deepwater Horizon oil rig exploded on 20 April 2010, killing 11 workers and unleashing an 87-day undersea geyser of oil that spewed at least 518 million liters. Five years later, the disaster's legacy is still evident in places like Barataria Bay, a pocket of islands, inlets, and bayous, that endured some of the heaviest oiling, creating scenes of devastation replayed endlessly on screens around the globe. To study the aftermath, researchers are still working at the sites trying to understand the spill's impacts.
Oil released during the Deepwater Horizon disaster injured plants, wildlife, and entire ecosystems. The oil posed a widespread threat from the deepest reaches of the Gulf to its shorelines. Both private and public lands were adversely affected, including critically important national and state wildlife refuges and parks, and national estuarine reserves.
Much of the released oil rose through the water column to the surface, encountering marine life on the way. At the water’s surface, the oil and dispersants spread out in a layer of contaminants that moved slowly towards the Gulf coast. Many kinds of fish and wildlife were exposed to this floating oil, not only during the spill, but for some time after the spill ended. Much of the floating oil made it to barrier islands and shorelines, where it affected wildlife, people, and the way people traditionally enjoyed the Gulf’s resources for recreational and other activities.
Animals in the Gulf can come into contact with the oil in a number of ways. For example, they may swim through it, ingesting or inhaling it at the surface. These exposures can cause a variety of health impacts, including death to animals such as fish and shellfish; marine mammals; turtles; and birds.
Researchers studying the impacts of the spill on wildlife are finding both lasting damage and unexpected resilience. The oil has clearly left its mark on the ecosystem, affecting organisms small and large, from soil microbes to bottlenose dolphins. At the same time, the ecosystem and its inhabitants have bounced back in surprising ways. Shrimp can be found scavenging the sea floor again. Brown pelicans swoop and fly overhead. But Barataria Bay is still not the same as it was before the Deepwater spill. Dolphins in particular continue to show adverse effects.
After five years of study, researchers still don’t have all the answers about what the future holds. New harmful impacts could be discovered that could affect not just the wildlife, but also the livelihoods of thousands of Gulf Coast families.
Now try and answer these questions:
- How far has the oil spread through the Gulf Coast?
- Which type of wildlife might be affected?
- Which animals seem to be the most affected?
- Which animals seem to show the most resilience?
- Have some parts of the Gulf recovered?
For more about humans' impact on our oceans, check out the Changing Oceans Science Update.
Though it is on the long side, Science magazine's podcast on The 5th anniversary of the Deepwater Horizon oil spill discusses the role of science in responding to the oil spill in the Gulf of Mexico and the state of ecological recovery five years later.
Looking Back at the Gulf After the Spill: A Photo Gallery provides 18 photos and text about the aftermath of the Deepwater Horizon oil spill.
To help your students learn more about the Deepwater Horizon oil spill, you can use the resources found in the Science NetLinks' 2010 Gulf of Mexico Oil Spill collection.
You also can extend your students' learning by having them listen to another source of water pollution in Nitrogen Pollution.