redOrbit Staff & Wire Reports – Your Universe Online
The Deepwater Horizon disaster could have a lasting impact on the Gulf of Mexico, according to a new paper suggesting that the region’s deep-sea soft-sediment ecosystem could take decades to recover from the 2010 oil spill.
The authors claim that their study, which was printed last month by the online journal PLoS ONE, provides comprehensive results on the spill’s effect on deep-water communities at the base of the Gulf’s food chain for the first time.
The spill resulted from an explosion on board the Deepwater Horizon oil rig that occurred on April 20, 2010, and resulted in a total of 4.9 million barrels (205.8 million gallons) of crude in what went on to become the largest offshore oil spill in US history.
In gauging the long-term effect of the disaster, the scientists conducted a 2011 cruise to collect additional data from sites that had been previously sampled in the fall of 2010. Specifically, they looked at the Gulf’s soft-bottom muddy habitats, examining biological composition and chemical composition at the same time and at the same location.
“This is not yet a complete picture,” said lead scientist Cynthia Cooksey of the National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science. “We are now in the process of analyzing data collected from a subsequent cruise in the spring of 2011. Those data will not be available for another year, but will also inform how we look at conditions over time.”
“As the principal investigators, we were tasked with determining what impacts might have occurred to the sea floor from the Deepwater Horizon oil spill,” Dr. Paul Montagna, Endowed Chair for Ecosystems and Modeling at the Harte Research Institute for Gulf of Mexico Studies, Texas A&M University-Corpus Christi, added. “We developed an innovative approach to combine tried and true classical statistical techniques with state of the art mapping technologies to create a map of the footprint of the oil spill.”
Typically, when researchers investigate offshore drilling sites, Montagna said that researchers typically find pollution between 300 and 600 yards from the site. However, during their most recent expedition, he said that they found it nearly two miles from the wellhead, with “identifiable impacts” of the pollution observed more than 10 miles from the actual site. Previously, experts had been unable to identify the effect on bottom of the vast underwater plume, and the “devastating” effect that the Deepwater Horizon spill had on the sea floor.
According to the researchers, the oil spill and plume covered nearly 360 square miles, with the most severe reduction of biological abundance and biodiversity occurring in a region roughly nine miles around the wellhead. Moderate effects were also observed 57 square miles around the wellhead, they added.
“The tremendous biodiversity of meiofauna in the deep-sea area of the Gulf of Mexico we studied has been reduced dramatically,” said Dr. Jeff Baguley, an expert on meiofauna (small invertebrates that live in both marine and fresh water) from the University of Nevada, Reno. “Nematode worms have become the dominant species at sites we sampled that were impacted by the oil. So though the overall number of meiofauna may not have changed much, it’s that we’ve lost the incredible biodiversity.”