May 19, 2010 11:53 AM by Melissa Canone
NEW ORLEANS (AP) - 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,
"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
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
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
Nobody knows how many whale sharks there are worldwide. Bob
Hueter, director of Mote's Center for Shark Research, said they may
number 500,000, a small number for fish.
He said he has sent an alert to the up to 300 people who've
reported whale shark sightings to him over time, asking them to be
on the watch.
"It's just critical," he said. "We're in desperate need of
knowing where the animals are at. Where are they in relation to the
The number of sightings rose sharply last year, to about 160
from the average of 80, as more people learned about Hoffmayer's
research. It was unclear whether there are more whale sharks or if
more people are looking for them.
Last year's reports included some a mile off the Florida
panhandle and Alabama coast. "That's the first we'd heard of in 25
years from that region," Hoffmayer said.
He said most of the whale sharks are seen in at least 200 to 300
feet of water and 30 to 40 miles off the river's mouth.
"Most is in 200, 300 feet of water at the very least. Thirty to
40 miles off the mouth of the river."