Jeb Byers, associate professor in the Odum School of Ecology, has been appointed to the National Research Council's Committee on Assessing Numeric Limits for Living Organisms in Ballast Water. The committee will conduct a study to inform the U.S. Environmental Protection Agency and the U.S. Coast Guard how to establish environmentally protective ballast water discharge limits in the next Vessel General Permit, which regulates discharges incidental to the normal operation of vessels.
Many ships carry salt or fresh water in their cargo holds to provide stability during transit, and this ballast water often contains living organisms. These are discharged, along with the water, when the ships enter port, introducing often-invasive non-indigenous species (NIS) to water bodies.
Byers explained that this causes serious problems for aquatic ecosystems around the world. “The best way to describe it is biological pollution,” Byers said. “If it was oil being discharged from these ships, people would be up in arms. But the biological organisms discharged in the ballast water in some ways can cause more damage, because if they establish populations they create a chronic, persistent problem. Ports around the world have major problems due to discharges from ballast water. For example, San Francisco Bay is overrun by NIS. There are 300 non-native aquatic species in San Francisco Bay, making up ninety to ninety-five percent of the Bay’s biomass. Ballast water was the major source for introducing these species.”
The U.S. EPA and the U.S. Coast Guard are seeking to establish ballast water discharge limits that will safeguard against the establishment of new aquatic NIS and protect existing indigenous populations of fish, shellfish, and wildlife. The NRC appointed the multi-disciplinary Committee on Assessing Numeric Limits for Living Organisms in Ballast Water, made up of nine experts, to help inform their efforts.
The committee will evaluate various approaches to assessing the risk of establishment of aquatic NIS given certain concentrations of living organisms in ballast water discharges. They will recommend how these approaches can be used by regulatory agencies to best inform risk management decisions on the allowable concentrations of living organisms in discharged ballast water. Finally, they will evaluate the risk of successful establishment of new aquatic NIS associated with a variety of ballast water discharge limits that have been used or suggested by the international community and/or domestic regulatory agencies.
The study will cover estuarine and freshwater systems, including the Great Lakes and other inland navigable waters, as well as the waters of the three-mile territorial sea. The committee will issue its report in mid-2011.