'Gulf spill killed 153 dolphins in 2011'

According to the National Oceanic and Atmospheric Administration, 153 dolphins, 65 of them babies, have been found dead in 2011, AFP reported.

Since the devastating British Petroleum oil spill in April 2010, the total number of dolphins found dead has reached 300, and environmentalists believe that the intelligent animal's death toll is actually 50 times what washes up to the shores; "the tip of the iceberg" as it is called.

In a study on the effects of the spill, marine expert Graham Worthy of the University of Central Florida, along with 26 other experts, said the dolphins were found in a part of the Gulf that saw nearly five million barrels of crude leak in the worst oil spill in US history.

"I suspect what we might be seeing are several things coming together to form a perfect storm," Worthy said.

"If oil and the dispersants have disrupted the food chain, this may have prevented the mother dolphins from getting adequate nutrition and building up the insulating blubber they needed to withstand the cold."

BP last month pledged $1 billion to jump-start projects aimed at restoring the US Gulf Coast by rebuilding damaged coastal marshes, replenishing soiled beaches, and conserving ocean habitat to help injured wildlife recover.

By the time the well was capped 87 days later, 4.9 million barrels (206 million gallons) of oil had gushed out of the runaway well 5,000 feet (1,500 meters) below the surface of the Gulf of Mexico.

Over a million gallons of dispersants were also deployed to break up the oil on the surface and deep underwater, and the environmentalists cautioned that their use was also a health hazard to animals and plant life in the Gulf, in some cases forcing large amounts of the oil to simply sink and clump together.

Hundreds of miles of fragile coastal wetlands and beaches were contaminated, a third of the Gulf's rich US waters were closed to fishing, and the economic costs have hit tens of billions of dollars.