Deepwater Horizon: Not Over Yet

Feb. 7, 2017
Ec Jk Blog

Nearly seven years on, we’re still feeling the effects of the Deepwater Horizon oil spill in some unexpected ways. A survey conducted by NASA and the US Geological Survey shows that areas of the coast where oil washed ashore have receded more quickly than they did before the spill. The length of shoreline that receded more than 13 feet a year quadrupled compared to the year before the spill.

Scientists used aerial imagery to compare the shoreline of Barataria Bay, on the western side of the Mississippi Delta, starting a year before the spill to two and a half years after it. The spill lasted from April to September 2010, although reports showed the well was still leaking as late as 2012.

The areas of shoreline researchers studied were fairly stable before the spill, with only isolated areas of erosion. In the year following the spill, areas that had received a heavy coating of oil experienced greater rates of erosion. Perhaps most troubling is that two years after the spill, even those segments of the shore that received only small amounts of oil were experiencing greater erosion. The reason, scientists believe, is that the oil killed vegetation and destroyed the root systems that had strengthened the shoreline.

Nearly two years after the spill, Hurricane Isaac hit this section of the coast. According to the lead researcher, “Our study uniquely shows that the patterns of shoreline recession seen in this region can be directly related to distinctly different causes: broadly dispersed erosion due to oiling from the Deepwater Horizon spill, and enhanced, but spatially limited, erosion due to intense storm impacts.”

Another member of the team noted, “Being able to compare shoreline losses in a year without any major storm to losses both after the Deepwater Horizon oil spill and after the hurricane was essential to correlating the erosion of the marsh to its underlying causes.”

The research team also says that because of the levees along the Mississippi River that prevent sediment deposition in the area, some of the eroded areas are unlikely to be reestablished. However, USGS and NASA scientists say that the techniques developed to measure shoreline erosion in this case—based on imagery from NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR—will help to more accurately gauge future erosion patterns.

About the Author

Janice Kaspersen

Janice Kaspersen is the former editor of Erosion Control and Stormwater magazines.