Almost three years after the Deepwater Horizon rig exploded, killing 11 men and resulting in the country’s largest oil spill, its impacts linger and the extent of the damage is unknown, according to a new report from the National Wildlife Federation.

The report, “Restoring a Degraded Gulf of Mexico: Wildlife and Wetlands Three Years into the Gulf Oil Disaster,” details high dolphin mortalities, sea turtle strandings, acceleration of coastal erosion and damaged deep sea coral, among other things.

“Three years after the initial explosion, the impacts of the disaster continue to unfold,” Doug Inkley, a senior scientist with the National Wildlife Federation, said during a Tuesday news conference.

Research to determine the extent of the damage is largely being done through the Natural Resource Damage Assessment process, which is still ongoing and confidential for now.

“We really won’t know for years if we will see that impact later,” Inkley said. “The Gulf oil disaster is not over.”

Of the handful of indicators the report examines, coastal wetlands, Atlantic bluefin tuna and sea turtles are rated as being in poor condition.

Wetland loss and degradation has been an issue in Louisiana for decades, but the April 20, 2010, oil leak accelerated some of the negative effects. “Restoring coastal wetlands are the most effective way to mitigate the effects of the oil spill,” Inkley said.

Captain Ryan Lambert, owner of Cajun Fishing Adventures in Buras, has been guiding people in south Louisiana for 33 years and said he’s seen how the oil leak has accelerated marsh loss.

During the oil disaster, he said, oil was hitting the coastal marshes in certain areas.

“When you go back now, they’re gone,” Lambert said. “In the last six months, I’ve never seen the marsh recede as much as it has now.”

A recent map from National Oceanic and Atmospheric Administration updating where water and land are in several areas of Plaquemines Parish outlined land loss in red, Lambert said.

“The whole map is red,” he said.

Lambert echoed the report in saying the money from the Deepwater Horizon fines and penalties are needed to implement the restoration and protection projects in Louisiana’s master plan.

“If we don’t get this done we can’t live here anymore,” he said.

David Muth, director of the Mississippi River Delta Restoration program with the federation, said in addition to damage, there are ongoing problems as buried oil gets resuspended over time.

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“Here on the ground in Louisiana, the disaster is ongoing,” Muth said. Last year, he said, six million pounds of tar mats and other material from the leak were picked up from Louisiana’s coast alone.

The report also highlights the number of dead dolphins.

According to NOAA, the number of dolphin strandings from Louisiana through Franklin County, Fla., was elevated in March.

The average number of strandings from 2002 through 2009 for March was about 18 dolphins, but this year there were 30, according to NOAA. Although that’s higher than normal, it is lower than the 45 strandings last year or the 70 reported in 2011. Most of these strandings involved one dead dolphin.

NOAA officially declared an “unusual mortality event” in December 2010 because of the high number of bottlenose dolphin deaths that started in February of that year.

NOAA research indicates that the two most common causes of dolphin die-offs — morbillivirus or marine biotoxins — do not appear to be a factor in this latest event.

“So the problems continue,” Inkley said. “How long it will continue is anyone’s guess.”

Although the report focuses on the damage to wildlife and habitat along the northern Gulf of Mexico coast, its recommendations focus on how fines and settlement money should be used.

Among the recommendations are the following:

  • A U.S. Department of Justice statement that says the companies responsible for the oil spill must be held completely accountable.
  • A final settlement must include provisions for addressing problems future problems.
  • Officials should commit the RESTORE Act money from Clean Water Act fines to ecological restoration.
  • The federal government must reform oil and gas leasing and permitting to better protect the environment.

BP spokesman Craig Savage said Tuesday that the company responded quickly with a $14 billion cleanup effort as well as funding early restoration projects in the wake of the Deepwater Horizon accident.

“Since May 2010, BP has been working with federal and state agencies to study the potential impact of the Deepwater Horizon accident on marine mammals and other wildlife, including dolphins,” Savage wrote in an email. “The studies are ongoing and preliminary data are still being analyzed in order to better understand potential effects on wildlife.”