Disposal zones were designated from Florida to Texas, said Bryant, who will discuss his research findings at the International Dialogue on Underwater Munitions conference that begins Monday in San Juan, Puerto Rico.
While the practice of dumping bombs and chemical weapons, including mustard and nerve gas, in the ocean ended 40 years ago some effects are just beginning to be seen, saidTerrance Long, founder of the underwater munitions conference.
"You can find munitions in basically every ocean around the world, every major sea, lake and river," Long said. "They are a threat to human health and the environment."
The oil industry is no stranger to leftovers from the World War Two.
Last year, BP shut its key Forties crude pipeline in the North Sea for five days while it removed a 13-foot (4-metre) un exploded German mine found resting cozily next to the pipeline that transports up to 40 percent of the UK's oil production.
BP discovered the mine during a routine pipeline inspection, then spent several months devising a plan to lift the bomb and move it far enough from the pipeline to safely detonate it.
In the Gulf of Mexico, which accounts for 23 percent of U.S. oil production and 7 percent of domestic natural gas output, the hazards are known, but generally ignored.
In 2001, BP and Shell found the wreckage of the U-166, a German World War II submarine, 45 miles (72 kms) from the mouth of the Mississippi River during an underwater survey for a pipeline needed to transport natural gas to shore.
Bryant said he and colleague Neil Slowey have documented discarded bombs and leaking barrels over the past 20 years while conducting research for energy companies in the Gulf of Mexico.