Boaters, divers, fishermen and commercial seafood trawlers have no way to steer clear of the dumpsites.
That's because the Army has put only one of its 26 known chemical weapons dumps on nautical charts, according to records kept by the National Oceanographic and Atmospheric Administration.
That agency, the Minerals Management Service, knows only what the Army has revealed to that agency: that chemical weapons were dumped at sea and that some are in the Gulf of Mexico and off South Carolina, agency records show.
The effect of the dumping operations has never been studied. Few scientists knew that it was done, so studies of the decline in sea life over the years has never focused on the possibility of leaking chemical weapons.
Commercial fishing operations, as well as scallop and clam trawlers, have been forced to go farther and farther from shore over past 25 years because sea life has thinned for unknown reasons. Some scallopers now dredge in up to 400 feet of water, which is more than 100 miles from the shore in some East Coast locations.
The bottom-dwelling cod population in the Northern Atlantic has been decimated.
Hundreds of bottlenose dolphins mysteriously washed up on Virginia and New Jersey shores in 1987. They died with large, never-explained skin blisters that resembled mustard gas burns on humans.
Federal marine scientists ultimately attributed the unprecedented number of dolphin deaths to a combination of morbillivirus - related to distemper in dogs - and potent vibrio bacteria from industrial pollutants.
That combination has killed other marine mammals over the years. But none has ever been found with its skin partly peeling off.
One marine mammal specialist who suspects that leaking chemical weapons killed the dolphins met Army officials and was told dumping had been done. But he was assured the weapons were unloaded too deep to harm the coastal-living creatures.
"You'd see the photos and you'd say, 'Man, this animal was burned by something,' " said Bob Schoelkopf, director of the Marine Mammal Stranding Center in Brigantine, N.J. He said "it is a very good possibility" that leaking chemical weapons killed the dolphins.
"It'd be nice to see the Army go down there and investigate, but nobody wants to open that book, it seems," Schoelkopf said. "You'd think they'd want to go look at those sites and say once and for all this isn't a problem. The amazing thing is they are not being monitored."
The Army also wondered whether its chemical weapons were responsible for the dolphin deaths and was preparing to investigate some dump zones. The project was scrapped when the deaths were attributed to the virus and bacteria, the Army's Brankowitz said.
LITTLE OR NO MONITORING
Over the decades, the Army has conducted environmental tests on only four of its dumpsites - and none since 1975.
Some of the last tests the Army conducted were on the nerve-gas-filled ships off New Jersey. They found no evidence the weapons had leaked, Brankowitz said.
He said that led the Army to presume the pressure on the weapons as they sank to the bottom crushed the shells and made them squirt their deadly contents onto the seabed, where they long ago broke down into their non-lethal chemical components.
That might be wishful thinking, some scientists said.
Shells filled with chemical weapons are more likely to slowly leak over time than to be crushed while sinking, said Peter Brewer, a marine scientist at the Monterey Bay Aquarium Research Institute in California.
DECADES OF DUMPING CHEMICAL ARMS LEAVE A RISKY LEGACY