“It’s undeniable, there must be a reason it’s attracting them,” he said, noting that the number of annual fishing trips to one subway car site rose from 300 to 17,000. “That’s the kind of impact something like that can have.”
But some scientists worry that anglers may be catching and consuming fish that have absorbed contaminants leaching from decommissioned vessels. These ships have carcinogenic polychlorinated biphenyls (PCBs), as well as oil, asbestos and other pollutants.
The EPA, which issued guidelines for ship sinking in 2006 along with the Transportation Department’s Maritime Administration, requires that any ship destined to become an artificial reef not contain PCB levels above 50 parts per billion. But some fish can accumulate PCBs in their bodies over time as they consume smaller fish, causing their contaminant levels to rise above that threshold.
Jon Dodrill, environmental administrator for the Florida Fish and Wildlife Conservation Commission’s division of marine fisheries management, has been monitoring PCB levels in reef fish near the site of the USS Oriskany, a naval aircraft carrier that was sunk to create a reef in May 2006. State officials identified a spike in fish-tissue PCB contamination a year after the sinking.
Since then, the contamination levels have dropped below advisory levels, although the most recent round of test results found elevated PCB levels in two red porgy and two scamp grouper that were sampled. “We’re interested to see if this downward trend continues or stabilizes at a lower level,” Dodrill said, adding that the peak levels of contamination would be a problem only for people relying on these fish for their main source of food.
Maine sanctuary managers are hoping that the increase in divers and anglers near artificial reefs will ease human pressure on natural reefs. Sean Morton, superintendent of the Florida Keys National Marine Sanctuary, said that a sunken ship off Key Largo has diverted tourists from neighboring natural reefs but one off Key West has not.
“There’s no need to get any more artificial reefs done at this point, until we know the impact of what we’ve already done,” Causey said of the Florida Keys.
In the meantime, the $945,000 project to clean, reconfigure and sink the Radford is close to completion. Contractors have removed the wiring, ductwork and gaskets that could contain PCBs, and they continue to test for remaining traces of the chemicals. They have auctioned off the brass, bronze and other exotic alloys from fixtures and opened up vertical shafts and missile silos. EPA inspectors continue to do final checks on the project, and contractors are focused on cleaning some remaining engine rooms.
After towing the Radford to its designated site later this month or in early August, contractors will cut holes in the ship, which participated in the Persian Gulf War as well as the Navy’s bombardment of Beirut in the early 1980s. Then the vessel, which went out of service March 18, 2003, will sink beneath the waves.