Scientists look for lingering damage from BP oil spill

The Orlando SentinelMay 27, 2011 

ORLANDO -- If dolphins could turn out for a roll call, then biologist Graham Worthy would have a much easier task determining the survivors, victims and overall harmful effects of the massive oil spill last spring and summer in the Gulf of Mexico.

Mattie? Here.

Tabbs? Here.

Xeno? Xeno?

But since a dolphin roll call and other such straightforward assessments aren’t a possibility, Worthy and dozens of other Florida scientists who met Wednesday and Thursday at the University of Central Florida have been forced to probe bits and pieces of evidence in the wake of the nearly three-month spill from an offshore well drilled by oil company BP PLC.

Their general and early consensus: A significant measure of luck was on the Gulf’s side last year, in that the crude oil could have been much more poisonous and the currents could have carried a lot more of it to Florida’s shores.

The spill began April 20 under mile-deep waters nearly 50 miles south of Louisiana and spread slowly before reaching Panhandle beaches in early June.

The scientists, whose efforts to study the effects of the oil spill are being coordinated by the Florida Institute of Oceanography with a $10 million grant from BP, said that they are most worried that some degree of ecological collapse is taking shape in ways they don’t yet have the knowledge or tools to measure or predict.

Signs of some serious trouble were presented on the first day of the meeting, including observations of new, predatory species that are capable of inflicting damage on coral and sponge ecosystems.

David Hollander, professor of chemical oceanography at the University of South Florida, said water samples collected in pressure-holding containers at great depths were found to contain dissolved “benzene, toluene and xylene, all of these extraordinarily toxic and carcinogenic compounds.”

And William Patterson, marine fisheries ecologist at the University of West Florida, said there have been widespread reports along the Panhandle coast of popular fish, such as red snapper, having large areas of rot, missing fins, strange colors, lesions, parasites that cause bulging growths and extensive loss of scales.

“Not only are these being reported by fishermen, contrary to reports about scientists not seeing them, we are seeing them. And we are also getting them on video,” Patterson said.

The scientists said much investigation remains to be done to determine the potential consequences of those and other findings.

For Worthy, a University of Central Florida professor, getting a better understanding of the fate of dolphins has meant returning to a familiar research destination: Choctawhatchee Bay, which lies just inland from the coastal cities of Fort Walton Beach and Destin.

Choctawhatchee Bay is one of the few places along Florida’s coast where scientists had identified and monitored bottlenose dolphins for at least several years before the spill occurred.

Since the BP spill, Worthy and students have collected nearly 40,000 photos of dolphins’ dorsal fins, which have distinctive and unique features, collected a limited number of dolphin skin biopsies and netted tons of small fish that the dolphins there feed on.

With those photos, Worthy will conduct a painstaking review to see which dolphins observed before the spill are no longer in Choctawhatchee Bay.

But that assessment is only for waters in and near Choctawhatchee Bay and not the vastly larger Gulf of Mexico.

“People ask, ‘How many dolphins died and how many do we have today?’” Worthy said. “We may be able get assessments of how many dolphins we have today. But in general, we couldn’t tell you how many dolphins are gone because we don’t know how many there were before the spill.”

Worthy said the oil and dispersants used to clean up the spill may have disrupted the food chain and prevented dolphin mothers from building up insulating blubber they need to withstand cold.

That could contribute to calves dying, though there are other possible explanations, said Worthy. He said one of the theories on the deaths is there was an altered food web and in the fall, mothers should be building fat to get them through cold snaps.

“If that didn’t happen, you could see how a cold snap could push them over the edge and cause them to have a loss of a newborn,” he said.

More than 150 bottlenose dolphins have washed up on Gulf coasts since January, including 65 newborn, infants, stillborn or those born prematurely. Only a tiny percentage of dolphin bodies actually reach shore so the actual deaths are likely several times higher, Worthy said.

There hasn’t been a significant die-off of dolphins in Choctawhatchee Bay. But Worthy’s fear is that the fish that dolphins eat -- mullet, sea trout and others -- were hard hit by the oil spill during spawning.

If significant numbers of young fish were wiped out, then dolphins may be faced with a shortage of food in coming years, he said.

“People are saying, ‘There’s no oil on the beach, there’s none floating around, everything looks good. So what was the big deal? Why was everybody worried about this spill?’” Worthy said.

“I have a feeling these impacts are going to take a little while to come to the surface, so to speak. Three to five years wouldn’t be unreasonable.”

-- Information from the Associated Press contributed to this report.

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