ORLANDO — Concerned about reports of sick fish turning up in the wake of last year's oil spill, federal officials have agreed to pursue an ambitious survey of the entire Gulf of Mexico using commercial fishermen to determine how many more fish might be affected.
"We're going to set up transects and use fishermen who know how to catch fish," said William Hogarth, a former federal fisheries official who now heads up the Florida Institute of Oceanography.
"It's one of the few times we've seen the fishing industry — commercial and recreational — come to the table and beg to work with us," he said Wednesday.
Hogarth and Steve Murawski, another former fisheries official who's now at the University of South Florida, had pushed for the $400,000 study, which will stretch from the Florida Keys to the Texas coast.
Meanwhile, scientists from the University of South Florida have found plankton in the deep gulf that are suffering from genetic mutations, and they have also found signs of what one called a "dirty bathtub ring" in the sediment on the gulf bottom, they revealed at a science conference Wednesday.
"What the ultimate impact of the mutation is, we don't know," said David Hollander of USF. Nor do they know yet whether last year's oil spill is to blame — the same status as the investigation of what's making red snapper and other fish sick.
"The jury's still out," said Will Patterson of the University of West Florida, one of the scientists investigating the ailing fish.
Red snapper began turning up over the winter showing lesions, fin rot and parasite infections. On some of them, the lesions had eaten a hole straight through to the muscle tissue. They also had enlarged livers, gallbladders, and bile ducts that some scientists believe show their immune systems had been compromised — possibly by oil.
Although they are running tests on those internal organs, "we don't have any data to report as of yet," Patterson told scientists at the two-day meeting on the University of Central Florida campus.
Jim Cowan of Louisiana State University said species other than red snapper are now turning up with similar symptoms. He said tilefish caught in 1,200 feet of water off Louisiana showed "a pretty high frequency of sores."
Cowan said his own research team went into the gulf recently and "about 20 percent of the fish we caught had visible signs of disease on the outside or the inside."
While the initial reports about sick fish garnered headlines this spring, the state's top wildlife scientist has expressed some reservations about whether those symptoms are unusual.
"We know a lot of these situations occur naturally," said Gil McRae, head of the Fish and Wildlife Research Institute in St. Petersburg. In years without oil spills "we get two calls a week" about fish with similar symptoms, he said.
The federally sponsored study, with its methodical sampling methods, should help resolve the issue, Hogarth said.
Meanwhile, there are other indications something unusual may be going on in the gulf. Patterson has been studying the gulf's deep reefs since 2009. He said that small fish that eat plankton — fish he said were "abundant" on the reefs prior to the spill — disappeared afterward. But again, there is no definite connection to the spill.
The studies Patterson and Hollander discussed at the conference are part of an unprecedented effort to gauge the impact of the spill last year. One scientist said his team had measured the growth of 37,000 oysters so far.
One of the biggest problems facing the scientists — a complaint voiced repeatedly Wednesday — was that there were so few studies of what might be "normal" for the gulf prior to the spill.
The Deepwater Horizon rig exploded on April 20, 2010, killing 11 workers. Two days later oil began spewing from a pipe a mile beneath the water's surface, and BP and its partners were not able to stop it until July.
Before BP could cap the well, 5 million barrels of oil gushed into the gulf. The company sprayed 1.8 million gallons of chemical dispersant to prevent at least some of it from reaching shore, but 2.5 million pounds of it washed up on Florida's beaches and in its marshes.
Florida's beaches appear clean now, and the tourists are returning. But there are signs that the spill still isn't over along the gulf. Dana Wetzel of Mote Marine Laboratory in Sarasota said she was doing some aquatic toxicology sampling in Louisiana last week and saw oil still washing up in Barataria Bay — and not just a light sheen, either.
"It is liquid oil," Wetzel said. "Stuff you can scoop up in your hands."