Cholera Found in Water From Freighters
 Anita Huslin / Washington Post 2nov00

Significant concentrations of a form of cholera capable of causing fatal intestinal illness have been found in ballast water released by transoceanic freighters into the Chesapeake Bay, according to a study published today.

Conditions in the bay do not appear conducive for the microbes to flourish, according to scientists who reported their findings in the journal Nature. But news of the microbe's presence has underscored concerns about the potential for spreading diseases and alien species from port to port as international ships have become faster and larger.

"Each day, it's a game of ecological roulette, and when we'll lose, we're not sure," said Ann Swanson, executive director of the Chesapeake Bay Commission.

The cholera bacteria was found with other microbes and viruses in the ballast of ships arriving in Baltimore and Norfolk in the last three years. Scientists cannot be sure that their presence is not harmful because they still don't know how microorganisms are transported throughout the world in ballast water, nor do they know how they may adapt to their new environments, said the study's lead scientist, Greg Ruiz.

"We don't know what's coming in, nor do we know what's taking hold and what effect it's having," said Ruiz, a biologist at the Smithsonian Environmental Research Center in Anne Arundel County.

Although a direct connection has not been proven, scientists believe an Asian strain of cholera bacterium transported by ballast water caused an outbreak in Latin America in the early 1990s, and the microbe has been found in shellfish beds in Mobile Bay.

After unloading their cargo in foreign ports, ships often take water into the ballast tanks to stabilize them on the return voyage. Then they dump the water--about 79 million tons in the United States each year--containing small fish, shellfish, bacteria and other microorganisms, when they near their destination.

Sometimes, the foreign creatures take hold and devastate native species.

Scientists now believe ballast water from the Black Sea was responsible for the well-publicized invasion of zebra mussels in the Great Lakes in the early 1980s. That invasion is expected to cause $5 billion in damages by 2002, mostly by clogging infrastructure, according to the U.S. Fish and Wildlife Service.

Researchers in Australia also believe that ballast water transported new species of algae to their waters, resulting in toxic blooms that closed commercial shellfish farms.

Recently, scientists have discovered genetic evidence that implicates Japanese oysters as the cause of MSX, one of the diseases that has decimated the Chesapeake fishery in recent years.

State and federal governments have been grappling with the problem in recent years. As of last year, ships that operate outside U.S. waters have been required to report to the Coast Guard where they take in ballast and where they dump it. Under a Maryland law passed this year, ships arriving in the Port of Baltimore will be required to report their ballast practices to the state as well.

Shippers have been encouraged to release their ballast water at sea to prevent the spread of exotic species. But the practice is costly and can be dangerous, according to shipping industry experts, and does not guarantee that new species will not end up in U.S. ports.

"There's got to be the development of a technological solution because ocean exchange, as I think this Nature article is saying, isn't that effective, and I don't think there's many people who'd argue with that," said Tom Chase, director of environmental affairs for the American Association of Port Authorities.

To avert a patchwork of legislation from states that are trying to regulate the problem, the association is lobbying for creation of a federal program to manage ballast practices and certify new technologies that could prevent the spread of invasive species.

Researchers at the University of Maryland and other institutions have been exploring ways of killing foreign organisms in ballast by treating the water with ultraviolet light, superheating it and filtering it.

Ruiz said the new study also highlights the need to consider the effects of such treatments on microorganisms, to ensure that they are not stimulated, instead of destroyed.