Oil spills not only represent a major disruption to the way of life for fishermen, but they also threaten the coastal wetlands, which are a critical part of the ecosystem.
The April 2010 explosion aboard the Deepwater Horizon rig resulted in a massive oil spill in the Gulf of Mexico that washed ashore, damaging a number of coastal areas. UH biology professor Steve Pennings conducted one of the first studies done on the effects of oil spills to salt marsh insects. I caught him at the airport, waiting to catch a flight:
"We were doing a geographic study of the insects in salt marshes before the oil spill. And so we had been sampling along the entire Gulf Coast and the entire Atlantic Coast, and when the oil spill happened, we expected some of our sites to be affected."
A grant from the National Science Foundation allowed Pennings to study some of the coastal salt marshes affected by the BP
"We sampled in places where not as much oil had gone, and the plants all looked perfectly healthy. And so a quick look at that marsh might lead you to believe that everything was fine. But in fact, the insects and spiders and crabs were strongly suppressed. So the first conclusion that we came to was that oil can have a big effect on the marsh food web, even if the plants are fine."
He says the fact that some plant life remained intact in these areas was key to how the insects recovered.
Pennings and UH graduate student Brittany McCall went back to the areas they examined a year later, to determine the reason for recovery. She says one factor might be that because the distance the oil slick had to travel, the weather helped reduce the toxicity before it hit the marshes.
"Another possibility might be that salt marshes are actually disturbed quite often by natural weather events. And so it actually might be a community adaptation to be able to rebound from disturbance, not necessarily an adaptation from an oil disturbance, but to disturbance in general."
Both McCall and Professor Pennings add that many more studies need to be done before the areas affected by the spill
are deemed totally recovered.
"I wouldn't our results to be interpreted as saying that the oil spill had no effect, or that it was all over in a year. The important lessons from our work is one that, even in areas that look unaffected there can be an effect. But if the plants stay healthy, the insects and spiders can recover."
For the entire study, visit the research article Disturbance and Recovery of Salt Marsh Arthropod Communities following BP Deepwater Horizon Oil Spill. Also, information can be found: http://www.uh.edu/news-events/stories/2012/march/SaltMarshStudy.php.