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Curbing Harmful Exotics
Along the Atlantic coastline as elsewhere, native species and ecosystems face serious threats from what have become known as marine bioinvasions. Examples include exotic zooplankton in Prince William Sound, zebra mussels, green crabs in Pacific coastal waters, and newly discovered veined rapa whelks (Rapana venosa) which prey on shellfish in the lower Chesapeake Bay. Several recent developments suggest that this problem may finally be getting the attention it needs.
President Clinton has signed an executive order to coordinate federal strategy. Federal agencies are directed to review their existing authorities. The order also creates an Invasive Species Council, to develop a comprehensive plan to minimize the economic, ecological, and human health impacts of invasive species and determine further steps to prevent their introduction and spread. The FY2000 budget proposes an increase of more than $28.8 million to combat these species.
At the First National Conference on Marine Bioinvasions at the Massachusetts Institute of Technology Sea Grant College in January, Secretary of the Interior Bruce Babbitt pointed out that marine bioinvasions have large consequences for the nation's health, food supply, economy, and fishing industry. He warned of their threat of degradation and homogenization of coastal waters everywhere.
Many exotic species arrive in U.S. waters from elsewhere in the world. But the Spartina choking the state of Washington's Willapa Bay, as well as Atlantic shad and other fish threatening native species in San Francisco Bay, come from the U.S. East Coast. We also export harmful species. Leidy's comb jelly, carried in ballast water from the U.S. to the Black Sea and lacking any predator, created one of the most intense marine invasions ever recorded. Babbitt said that the discharge of ballast water is "nothing less than point pollution and must be treated as such." As ships become larger and faster the opportunities for alien species to gain transport and survive the trip are multiplied, up to a hundredfold on some routes. He characterized our response to date as "pitiful," relying on "voluntary guidelines, a scattered approach and limited, unreinforced codes," and said, "No longer."
At the MIT conference, which had several co-sponsors, scientists, managers and industry representatives illuminated the complexities of trying to prevent or control marine bioinvaders. Marine species find many ways to travel to a new environment. Among them: ballast water, bottom fouling, aquaculture, the aquarium trade, and fisherman's bait. Secretary Babbitt did point out the large economic benefits that control can sometimes provide, such the program to curb lampreys in the Great Lakes. But he and others held that prevention was a top priority and usually a more effective and economic tactic than control or eradication.
Other speakers noted that introduced species have an evolutionary as well as an ecological impact and that the smallest organisms, such as viruses, bacteria and phytoplankton can do as much harm as larger ones. Particularly dangerous are marine pathogens, invasive algae, and organisms genetically altering native species. In addition to initiatives to prevent invasions from the many serious transfer vectors, speakers emphasized the importance of flexible funding to provide early response to budding new problems before they are out of control. While scientists at the Virginia Institute of Marine Sciences and North Carolina Sea Grant are already studying the veined rapa whelk, for example, new funds are required to enhance research and to control this predator.
In May the U.S. Coast Guard expects to publish an interim rule to implement the National Invasive Species Act of 1996 with voluntary guidelines asking vessels to conduct complete ballast change at sea outside of the Exclusive Economic Zone. Water sampling and the submission of reports are required for nearly all vessels with ballast tanks entering U.S. waters. In accordance with the Act, if the rate of compliance of self policing is found to be inadequate or if vessel operators fail to submit mandatory ballast water reports, the voluntary guidelines will become mandatory and carry civil and criminal penalties.
Contact jpeterso@mit.edu for information on the conference. URL for more on the veined rapa whelk: www.vims.edu/fish/oyreef/biab.hmtl |