Whale shark, world's biggest fish, very vulnerable to oil spill

By Janet McConnaughey, AP Writer
May 19, 2010, 11:37AM NEW ORLEANS — The world’s biggest fish may be highly vulnerable to the Gulf of Mexico oil spill and one of its favorite feeding grounds is in the area of the spill. Whale sharks feed on the surface, sucking plankton, fish eggs and small fish into their mouths. Surface oil could clog the cartilage filter pads that direct food to the back of their throat, and could coat their gills while they feed, said Eric Hoffmayer, a researcher at the University of Southern Mississippi who has been studying whale sharks in the northern Gulf since 2002. “If it did get their gills coated, I can only imagine they would suffocate relatively quickly,” he said. More than one-third of all whale shark sightings in the northern Gulf since 2002 have been off the mouth of the Mississippi River, Hoffmayer said. “The mouth of the river is the primary area where these things show up. Year after year after year,” he said. “This is a prime feeding area for them.” Oil has been leaking from a well 40 miles southeast of the river’s mouth since the rig Deepwater Horizon exploded and sank in April. Whale sharks can grow up to about 40 feet in length and are known to dive more than a mile beneath the surface. They were added in 2008 to the World Conservation Union’s list of threatened species. So far, Hoffmayer said, no whale shark has been seen in the spill. The vast majority are seen in northern Gulf waters from June through October as they migrate from the Yucatan area. “The best case scenario is they can detect the oil and will avoid it,” he said. Other types of sharks have been spotted near the oil. …

Whale shark, world’s biggest fish, very vulnerable to oil spill