Rutgers study predicts long-term effect of Deepwater Horizon oil spill on coastal species
A team of researchers from Rutgers and other institutions across the country, known as the Coastal Waters Consortium (CWC), has published a report predicting how different species might have impacted coastal marsh food webs after the 2010 Deepwater Horizon oil spill.
The report, which is based on information from several previous studies, started as an effort to learn more about the ecosystems the spill impacted, said Michael Polito, an assistant professor in the Department of Oceanography and Coastal Sciences at Louisiana State University.
“Following the oil spill … we realized that we didn’t know as much about how the coastal ecosystems that were likely affected by the oil spill worked and how they were put together,” Polito said. “(Our goal was) to come together and compile all the known information about coastal salt marshes in particular and about how … different animals and plants in those coastal salt marshes are connected to each other.”
Researchers gathered information that focused primarily on two things — how “important” species were to their food webs and how sensitive species were to oil, according to the report. Fifty-one species were analyzed.
Polito said a species' importance depends on how many connections it has to other species in its food web, and on how many other species depend on its existence for their own food web connections.
If an animal has a high quantity of connections and exists as a link between many different species in the food web, then it is considered important.
Knowing how important different species are to their food webs and how sensitive they are to oil helps to contextualize the oil spill’s impact, Polito said.
“If you understand those two factors … you can get a holistic understanding of not only how individual species are affected by oil, but (also of) how the whole food web is affected by oil,” he said.
Certain species that are very important and highly sensitive to oil, like gulls, terns and omnivorous snails, could potentially destabilize the food web, according to the report.
These species could be thought of as foundational bricks in a brick wall, Polito said
“There are some places where if you removed a brick the whole wall might fall down,” he said. “If you remove some of these sensitive species that are also very important to the food web … it could affect the stability of the wall.”
In contrast, other species, like certain types of carnivorous marsh fish, were very important to the food web but not that sensitive to oil.
Michael McCann, an urban marine ecologist at The Nature Conservatory in New York, said these species had an important role to play.
“Those (species) are the ones that are going to provide resilience to the overall food web,” he said.
McCann said he and his colleagues were intrigued by how insensitive to oil many species in the coastal salt marshes were.
“There’s a surprising amount of resilience in nature,” he said. “ We were kind of shocked about how tough some of these organisms are.”
There was no published information examining the oil sensitivity for 11 of the 51 species analyzed, according to the report. McCann said this was not ideal.
“That’s kind of a bad thing because there are a few (species) that are really important in the (food) the web, but we just don’t know how sensitive they are,” he said.
These species should be studied in the future, McCann said.
Species that are very important to their food webs and highly sensitive to oil should be a conservation priority, according to the report.
Olaf Jensen, a professor in the Department of Marine and Coastal Sciences, said conservation efforts would have to be selective.
“We can’t focus our restoration and protection efforts on every single species in the marsh,” he said. “And so we have to do some kind of prioritizing, trying to understand which species are either going to be most impacted by oil or which species are likely to be ok on their own.”
Jensen said the report could help inform people involved in conservation efforts.
“This kind of an analysis that we did allows oil spill response teams or managers to really understand where they should focus their efforts,” he said.
Maxwell Marcus is a School of Arts and Sciences senior. He is a contributing writer for The Daily Targum.