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Kopp, J.A., 2001. Trojan Vessels: Domestic Ballast Water Voyage Patterns in the United States, Smithsonian Institution and University of Washington (USA). Proceedings of the Second International Conference on Marine Bioinvasions, New Orleans, La., April 9-11, 2001, p. 78. Trojan Vessels: Domestic Ballast Water Voyage Patterns in the United StatesBallast water transported by ships is recognized as an important vector for the transfer and introduction of aquatic organisms between coastal ecosystems around the world. The United States primarily pays attention to the international dimension of this problem, as evidenced by the National Invasive Species Act of 1996, which requires ships entering U. S. waters that intend to discharge ballast to report their ballast water information and activity, and requests them to exchange ballast at sea, but exempts ships engaged in most coastwise voyages from any such provisions. The result of this international focus is that patterns of ballast water transfer into the United States are beginning to be documented and analyzed, but transfers between ecosystems within the United States remain poorly understood. There is substantial scientific justification for an equal level of concern about coastwise ballast voyages. It is known that plankton survival in ballast tanks is inversely proportional to voyage duration (Cohen, 1998). Since coastwise voyages tend to be shorter than international voyages, it is reasonable to assume a higher rate of plankton survival in the ballast that is transported in coastal voyages. It is also known that some U. S. ports have nonindigenous species that others do not. The San Francisco estuary, for instance, contains numerous nonindigenous aquatic species that do not occur elsewhere on the west coast, most of international origin (Cohen, 1998). Transfers of ballast from invaded ports to uninvaded ports increases the risk of the spread of these invasions. The United States, though one country, is home to many varied ecosystems along the coasts of its states, and transfers of ballast water between these ecosystems are no different from a biological perspective than transfers of ballast between ecosystems in different countries. This paper analyzes domestic voyage data collected from the U. S. Maritime Administration and the U. S. Army Corps of Engineers in order to document patterns of coastwise ballast water transport in the United States. Ballast water profiles are presented for major bioregions of the country, as well as for individual states and over 60 ports. For each of these locations, these profiles show where ballast water is received from and sent to and how many voyages are involved. These voyage patterns may be useful in predicting what areas are at risk areas. Comparison is made to international ballast voyage patterns for selected areas. Limitations of the data are also discussed, as are recommendations for changes to the National Invasive Species Act when it is up for renewal in 2002. Literature Cited: Cohen, A. N. 1998. Ships' Ballast Water and the Introduction of Exotic Organisms into the San Francisco Estuary: Current Status of the Problem and Options for Management. San Francisco Estuary Institute, Richmond CA. Contact: Joel Kopp, 4747 30th Ave. NE #F144, Seattle, WA 98105, USA |
