World’s biggest fish, threatened whale sharks, spotted swimming in heavy oil in Gulf of Mexico

By Janet Mcconnaughey, AP
Thursday, July 1, 2010

Threatened whale sharks seen in Gulf oil spill

NEW ORLEANS — Whale sharks, the huge fish that feed by vacuuming the sea surface, have been seen swimming between and through wide streamers of heavy oil a few miles from BP’s spewing well in the Gulf of Mexico, a federal scientist said Thursday.

The three sharks did not appear distressed and their white-spotted hides were not visibly oiled, said Steve Gittings of the National Oceanic and Atmospheric Administration, who saw them on a flight Monday to locate oiled sea turtles for rescuers in boats.

“Don’t get the picture that these looked like those pelicans you see photographs of,” he said.

But oil can clog their gills and suffocate them as they swim at the surface, and they will swallow oil if they feed in it, said John Carlson, fisheries biologist in NOAA’s wildlife section.

“They look like skimmer boats when they’re feeding,” Carlson said.

Gittings said the three he saw, which he estimated at about 25 feet long, were about 4 miles from the sunken Deepwater Horizon, in an area where skimmer boats were slurping the heaviest oil.

“There’s no continuous area of heavy oil. But there’s so many streamers they couldn’t avoid swimming through those streamers,” he said.

The question now is how many of the creatures are dying in the oil, said Eric Hoffmayer of the University of Southern Mississippi’s Gulf Coast Research Lab, who has studied whale sharks in the northern Gulf since 2002.

“Taking mouthfuls of thick oil is not conducive to them surviving,” he said.

Hoffmayer has found that many of the northern Gulf’s whale sharks feed off the mouth of the Mississippi River; the Deepwater Horizon site is about 40 miles southeast of the river.

“That basically confirms our worst fear: these animals do not know to stay away from the oil,” Hoffmayer said.

Scientists on a teleconference Wednesday agreed there isn’t any known way to make whale sharks swim away from oil, the way air cannon can be used to scare birds from airports, Gittings and Carlson said.

About all that can be done to protect them is make sure heavy oil is burned and skimmed from areas they might swim into, Carlson said.

They’re easy to recognize, up to about 40 feet long and black with rows of white spots.

But there won’t be any way to tell how many die. Sharks don’t float.

“If they do die from the oil, they’re going to sink to the bottom,” Hoffmayer said.

News of whale sharks in the oil came less than a week after a huge group was spotted elsewhere off the Louisiana coast where oil had not yet been found. One aerial photograph showed dozens of them.

“It blew my mind. There were probably more than a hundred sharks,” Hoffmayer said.

The group seen June 22 was about 70 miles southwest of Port Fourchon, and about 60 miles from the western edge of the spill as shown on a federal map, he said.

Hoffmayer said it was hard to say whether the three seen Monday were from that group because the animals can travel more than 60 miles in a day.

“I’ve got a feeling that until whatever the food source they found disappears, they’re not going to want to go,” he said.

Nobody knows just how many whale sharks exist. They’re on the World Conservation Union’s “red list” of threatened species, but not on any U.S. list of threatened or endangered species. Federal law does ban killing them for sport or commercial use, Carlson said.

Hoffmayer said the animals can dive a mile deep, and could escape any effort to herd them away from the oil.

Last week’s spotting came as part of a two-day excursion organized by the director of a documentary being filmed about marine biologist Sylvia Earle, creator of the Mission Blue Foundation.

Hoffmayer said four of the sharks were tagged.

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