Five years after oil spill, Gulf’s future still unknown

Unusual death rates for dolphins are among the top concerns for researchers

A stranded dolphin is studied by an official from the Louisiana Department of Wildlife and Fisheries. More than 1,300 cetaceans have been stranded along the Gulf of Mexico shores since the Deepwater Horizon oil spill, leading many researchers to believe the spill correlates with the sharp rise in unusual deaths, particularly among bottlenose dolphins. Photo Credit: Louisiana Department of Fisheries and Wildlife

(MEDIA GENERAL) – Five years after the explosion aboard the Deepwater Horizon drilling rig killed 11 workers and flooded the Gulf of Mexico with an estimated 4.9 million barrels of oil (more than 100 million gallons), a mixed message resounds from clean-up officials and those tasked with trying to return the Gulf region to its former self.

Yes, beaches have been cleaned, turtles and pelicans have been scrubbed and re-released into habitats, and local communities slowly have rebounded from arguably the worst environmental disaster in United States history. But so much is yet to be done, and the full impact of the oil spill largely is unknown, according to Ben Sherman, a public affairs officer with the National Oceanic and Atmospheric Administration, one of several federal agencies involved in the restoration effort.

“There’s just so much we don’t know yet,” Sherman said. “A large portion of the oil went to the bottom of the gulf. … We are doing more testing (to see how this will affect the seafloor habitats). … There’s major concern over the dolphins in the Gulf. We’ve seen the largest unusual mortality rate for dolphins, and it just happens to line up exactly with Deepwater.”

Following the spill, a taskforce dubbed the Deepwater Horizon National Resource Damage Assessment Trustees was created to evaluate the impact of the spill, known as a Natural Resource Damage Assessment (NRDA) process. Nine agencies comprise the Trustee’s taskforce: The NOAA, the U.S. Department of the Interior, the Environmental Protection Agency, the U.S. Department of Agriculture, as well as state officials from Alabama, Florida, Louisiana, Mississippi and Texas.

The trustees released a statement Wednesday, April 15, noting there is much more to learn and the mission remains a top priority to help restore the Gulf region.

“Five years after the devastating Deepwater Horizon oil spill, the (Gulf Coast Ecosystem Restoration Council’s) mission remains critical to restoring the ecosystem and economy for the people who live, work and play in the Gulf region,” said U.S. Secretary of Commerce Penny Pritzker, Chairperson of the Gulf Restoration Council, which is focused on the spill’s economic impact on the Gulf states. “(It is our goal) to make sure the Gulf Coast comes back stronger and more vibrant than before the disaster.”

Dolphins are dying, but why?

Following the spill, an unusual mortality event was declared for dolphins and whales (cetaceans) for the northern Gulf of Mexico. From February 2010 to April 12, 2015, 1,370 cetaceans, primarily bottlenose dolphins, washed ashore in Louisiana, Mississippi, Alabama and the Florida Panhandle. Of the beached cetaceans, 94 percent were dead.

From 2002 through 2009, only 74 dolphins were stranded, the NOAA official term, along those same shorelines.

One hypothesis for the sharp rise in strandings is a correlated rise between a common bacterial infection. Brucella bacteria commonly are found in populations of marine animals, but normally do not result in brucellosis, a fatal infection. According to a 2011 NOAA study, researchers believe “severe environmental stress, including an exposure to oil, could have reduced the animal’s ability to fight infection.”

Research continues on why cetaceans are dying off at a notably higher rate in the Gulf, but most studies to date point to the Deepwater Horizon oil spill as a primary culprit.

“In the current study, we found that dolphin deaths in Louisiana for 2010 and 2011 were the highest ever recorded for that state,” said Teri Rowles, Ph.D., head of NOAA’s Marine Mammal Health and Stranding Response Program, which is responsible for determining the causes of unusual mortality events.

The paper’s lead author, Dr. Stephanie Venn-Watson, went into greater detail, tying the cause to the spill.

“Several clusters of dead dolphins identified during this mortality event were consistent with the timing and spatial distribution with the (Deepwater Horizon) oil spill,” Venn-Watson said.

Per the NOAA study, “Among (the stranded), the grouping in heavily oiled Barataria Bay (August 2010 thru December 2011) had the longest duration of sustained, high numbers of dead or stranded dolphins. … A previously published study showed that Barataria Bay dolphins had adverse health impacts consistent with expected effects of exposure to petroleum products.”

BP’s response

Through the NRDA, the trustee group has completed, scheduled and planned restoration projects funded by a $1 billion settlement with BP, which commissioned the Horizon to drill in the Macondo oil reserves approximately 40 miles southeast of the Louisiana coast.

According to Sherman, $700 million of the settlement already has been used or earmarked for future projects. NRDA projects largely have been divided based on the focus on specific organisms or habitats, including marine mammals and sea turtles, fish and shellfish, birds and shoreline habitats, as well as human uses of natural resources (recreational fishing, boating, economic impact).

In 2014, the Deepwater Horizon NRDA trustees announced a restoration plan consisting of 44 projects totaling an estimated $627 million. About 63 percent — $397 million – of the projects will address ecological losses, while the remaining 37 percent — $230 million – will address lost recreational services.

BP and the Deepwater Horizon NRDA Trustees are at odds after the oil company issued a press release in March criticizing NRDA’s research approach.

“The data and studies summarized in (the NRDA) report are encouraging and provide evidence that the most dire predictions made after the spill did not come to pass,” said Laura Folse, BP’s executive vice president for response and environmental restoration. “The Gulf is showing strong signs of environmental recovery, primarily due to its natural resilience and the unprecedented response and clean-up efforts.”

Read the BP press release here:

To date, it is estimated BP has spent approximately $30 billion for claims payments as well as response, clean-up and early restoration projects headed by the Deepwater Horizon NRDA Trustees.

NRDA Trustee chair Samuel Plauche, in a statement regarding the fifth-year anniversary of the spill, strongly expressed his support for the NRDA process and the projects the Trustees have done to date.

“We recognize that the public is depending on us to hold BP and others accountable. Restoration of the Gulf’s natural resources is by no means complete,” Plauche said. “A growing body of scientific evidence is helping the NRDA Trustees learn more about the injuries sustained. This evidence has guided early restoration, and as a result we have initiated 54 projects. … While positive, this is just the beginning of restoration. We will continue to assess the full extent of the injury to our cherished natural resources to ensure restoration occurs.”

Credit: NOAA
Credit: NOAA

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