Friday, June 18, 2010

Can whales and dolphins adapt to oily Gulf?

The dead sperm whale found this week in the Gulf of Mexico puts the spotlight on how the BP oil spill will affect this endangered mammal, along with other cetaceans, such as dolphins, that must break the oil-slicked surface to breathe.

“These communities of whales and dolphins are already known to be stressed, because they’re dealing with other pollutants, like heavy metals, in the water,” says Emory neuroscientist Lori Marino, an expert in whale and dolphin intelligence and behaviors. “They are already compromised animals, and when they have something like this to deal with, it can be a tipping point for them.”

NASA satellite image, below, shows oil reaching Alabama beaches and the Florida panhandle. (Click on image to enlarge.)
It is unknown whether the deaths of the young sperm whale and the half-dozen dolphins that have been found washed up on Gulf beaches are oil related. Unlike the stark visual evidence of birds with oil-coated feathers, the toxic impact on whales and dolphins is primarily internal.

“They have to open their blowholes to breathe,” Marino says. “Imagine sticking your nose in a bowl and snorting oil. You’d be choking.”

A greater, and more lasting, impact may be the domino effect of toxins in the food chain, as oil droplets get into the fish and squid that cetaceans eat, she says.

Recent reports of large numbers of dolphins moving into shallow waters off Florida to flee the oil are troubling, Marino adds. “If they stay in the shallows and the oil comes in after them, they’ll be trapped.”

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Both oil spill and clean-up pose health risks
Gulf oil mess fuels interest in green energy

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