Experts emphasized their concerns, pointing to the mysterious deaths of hundreds of young dolphins and turtles, strangely stained crabs and dead patches on the sea floor.
Source: Press TV
A group of scientists have said the devastating oil spill in the Gulf of Mexico last year has caused significant declines in the body of water's key health indicators.
More than three dozen scientists have given a grade of 68 percent for the overall health of the Gulf as the Americans mark the first anniversary of the BP's oil spill, according to an Associated Press survey of researcher on Wednesday.
Scientists judge that the current grade is just a few points below the 71 the same researchers gave last summer when asked what grade they would give the ecosystem before the spill.
The spill caused by the explosion of the Deepwater Horizon's oil rig off the Louisiana Gulf Coast on April 20 last year left 11 workers dead, blackened beaches from Texas to Florida and triggered the United States' largest environmental disaster of all time.
According to official estimates, 4.9 million barrels (206 million gallons) of oil spewed out of Macondo well 5,000 feet (almost one mile) below the Gulf's surface.
Scientists say conditions have improved on the surface, however, there are still many unknowns about the long-term effects of the spill.
They have pointed to significant declines in key health indicators such as the sea floor, dolphins and oysters.
Experts also pointed to the mysterious deaths of close to 300 dolphins since the environmental disaster as well as strangely stained crabs and dead patches at the bottom of the Gulf.
On Tuesday, US President Barack Obama pledged to hold BP accountable for the worst environmental disaster in US history.
Obama, who was speaking on the occasion of the first anniversary of the Gulf of Mexico oil spill, also acknowledged that the "catastrophic event" deeply affected the lives of millions of Americans, from local fishermen to restaurant and hotel owners and small businesses throughout the region,