Five years after the Deepwater Horizon oil spill, which flooded nearly five million barrels of oil into the Gulf of Mexico in 2010, scientists are still struggling to unravel the mysteries of a natural habitat deeply impacted by the largest oil spill in U.S. waters.
National Geographic recently published the first part of a five-part series marking the incident’s fifth anniversary. In the first installment, titled “Is Gulf Oil Spill’s Damage Over or Still Unfolding?,” the magazine probed the minds of scientists and researchers devoting their time to discovering the way millions of gallons of oil has changed, or will continue to change, the Gulf of Mexico and the creatures that call that landscape home.
Austin Peay State University assistant professor of biology Stefan Woltmann was one of the scientific authorities approached, and he offered his thoughts on the bigger food chain of the Gulf and how the spilled oil impacted organisms that don’t even inhabit the water.
“There’s a lot of stuff that we, as scientists, don’t know because things are still playing out,” Woltmann said. “It’s a much different situation in the Gulf of Mexico than any other oil spills in history.
“For one, this is different because of the location where it happened, but also because of the sheer size of the spill – it’s the (second largest oil spill in U.S. history,)” Woltmann continued. “Everyone thinks of the Exxon Valdez spill, but it’s colder where that happened (in Alaska), it’s a lot rockier of an environment and there was really a lot less oil than (with the Deepwater Horizon spill).”
In the piece, author Craig Welch discussed the topic of Seaside Sparrows – a bird common in the Louisiana salt marshes that had greatly reduced populations in the first few years following the spill.
Woltmann, an expert in ornithology, or the study of birds, was an obvious choice to discuss the impact the 2010 spill had on the birds and the marshes they inhabit.
While the idea of sparrows, creatures that don’t dive or swim on the ocean’s surface, being affected by an oil spill may seem counterintuitive, scientists have discovered quite the opposite.
Meadows once rich with spiders, crickets and other prey for sparrows were greatly impacted by the spill of oil. As a result, scientists like Woltmann have observed a marked decrease in sparrow population in those areas – a surprising and potentially serious finding according to many in the scientific community.
“(The Coastal Waters Consortium) was looking at marsh ecology following the spill and this is where sparrows come into things,” Woltmann said. “They’re the main breeding bird out there and they live in those marshes all year long. They seemed to us to be a good indicator of the overall health of the marsh because they’re eating things that eat the plants, and if they don’t have plants, the entire food web can change.”
A complete understanding of the impact the spill had on the Gulf could take years, if not decades. As stated in the piece, scientists still do not have a complete view of the Exxon Valdez spill, which took place over 26 years ago.
It is that search for an answer they may never ultimately find, Woltmann said, that drives researchers like himself to study the impact of events like the Deepwater Horizon spill.
“This is the one of the largest uncontrolled experiments that has ever happened,” Woltmann said. “From a scientific standpoint, we’re much more in a forensic mode than an experiment mode because there’s no control here. We have nothing to compare this situation to and things are constantly shifting around us in nature.”
The National Geographic story can be found online at http://news.nationalgeographic.com/2015/04/150414-deepwater-oil-spill-birds-gulf-macondo-louisiana/. For more information on APSU’s department of biology, visit www.apsu.edu/biology.