A study newly published in a marine-science journal says a 2007 survey estimated about 85,000 lost lobster or crab traps could lie in Florida Keys National Marine Sanctuary waters.
"Lost traps may ... continue to catch and confine, often referred to as ghost fishing, both target species and bycatch," says the study published in the March edition of the journal Marine and Coastal Fisheries.
For the study, sanctuary staff performed 151 surveys by towing a diver along a transect line, in all covering about 300 acres of marine bottom.
"When the random surveys had been completed, it was apparent that a disproportionate amount of trap debris had been encountered on coral reefs, even though reefs covered less area than other habitats in the sample domain and in the sanctuary overall," according to the study.
"Derelict spiny lobster traps may move hundreds of meters during high wind events, resulting in tissue abrasion, breakage and often complete removal of critical seagrass, sponge and coral habitat," lead author Amy Uhrin of the federal Center for Coastal Fisheries and Habitat Research wrote in a summary.
Tom Matthews of the state Fish and Wildlife Research Institute in Marathon and Cynthia Lewis of the Keys Marine Laboratory in Layton were co-authors.
The report estimates that 1 million pieces of marine debris -- wood, concrete and plastic -- from traps may lie on the sanctuary bottom.
"There's no question that ghost traps are out there but those are awfully big numbers," said Bill Kelly, executive director of the Florida Keys Commercial Fishermen's Association.
Kelly said a 2007 survey likely counted traps lost during the exceptionally busy hurricane seasons of 2005 and 2006.
"Hurricane Wilma in 2005 resulted in one of the strongest storm surges experienced in the Florida Keys in more than 40 years," Kelly said. "Tens of thousands of spiny lobster and stone crab traps were displaced, lost or destroyed as a result of that storm."
Commercial fishermen recovered "enormous" amounts of debris after the storm, he said.
"A standard wood trap has a life expectancy of about a year," he said. "The worms eat the wood, and the concrete [base] turns to rubble."
Commercial fishermen work to recover lost traps and ropes in every closed season under a state-approved program, he said.