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Executive Summary
Human activities are profoundly affecting the earth's support systems. Population growth has been accompanied by a variety of stresses of natural ecosystems, including habitat destruction and modification, chemical contamination, and the unintentional introduction of various nonindigenous invasive species.
Some nonindigenous invasive species have had significant adverse effects on human, plant or animal health, local and regional economies, and on the ecosystems they invade. Recent examples of notorious invasive species include fire ants and African honey bees in the southern U.S., West Nile virus and Asian longhorn beetles in the eastern U.S. and Canada, and, of course, the zebra mussel in the Great Lakes and eastern half of the U.S. and Canada.
The Office of Technology Assessment (U.S. Congress, 1993) calculated almost $100 billion in U.S. economic losses over an 85-year period from just 79 nonindigenous species. Pimentel et al (2000) estimated losses to the United States economy of at least $137 billion per year associated with the effects of nonindigenous species on native ecosystems, agriculture, and natural resources, including the costs for control efforts. As noted by the Union of Concerned Scientists (2001), the accuracy of the Pimentel et al. calculations is difficult to assess, but probably is a minimum. In addition to economic and human health costs, nonindigenous invasive species are anticipated to be the leading cause of biodiversity change in lakes in the coming century (Sala et al., 2000) and of extinctions in North American freshwater ecosystems (Riccardi and Rasmussen 1999).
The Great Lakes are the largest freshwater ecosystem on earth (not counting the polar ice caps). They are the economic, cultural, and recreational lifeblood of millions of North Americans. They are the gateway to the heartland waters of the United States and Canada. Threats to the ecosystem have changed through the times, and so too must responses. Introduction of aquatic nonindigenous species is arguably the most serious economic and ecological threat to the Great Lakes today.
Key conclusions and recommendations include:
- Aquatic species invasions continue to pose one of the greatest risks to the health and productivity of our coastal marine ecosystems and the Great Lakes.
- A major federal funding increase of at least $30 million per year for the Great Lakes region is needed to push for rapid progress towards solutions to the problems outlined in this document. The piecemeal and relatively small annual funding requested by the Administration and provided by Congress, and the funds available through Canadian agencies, are not sufficient for substantive progress. Invasive species are no longer just a matter of scientific interest and local concern - they represent a threat to the marine/aquatic biosecurity of the United States, Canada, and the other coastal nations of the world. Invasive species have a direct impact where we live and play, and they affect our standard and style of living in an adverse manner. Winning the invasive species challenge means investing in a reasonable 10-year goal: to eliminate new introductions of aquatic invasive species by 2013. Oceanic shipping (ballast tanks) has been the primary vector for new aquatic species introductions and will continue to be the most significant and high-risk vector until effective treatment technologies are developed, proven, and made suitable for installation and use aboard a variety of large ships.
- Without government leadership and funding, availability of approved ballast water/ballast tank treatment technologies is at least a decade away, perhaps longer.
- The development of an effective, practical ballast water treatment standard or standards remains a major hurdle to progress on the development and testing of treatment technologies.
- The lack of reliable and flexible full-scale testing platforms is an obstacle to testing promising ballast water treatment technologies. Test platforms, in the form of leased vessels, shore-based test facilities, or MARAD vessels, need to be available for full-scale tests under actual vessel operating conditions.
- Given that many of the aquatic invaders that have established in the Great Lakes in recent years originate from Eurasia, an interdiction program based on assessment of potential high-threat invader organisms in European fresh and brackish water systems should be undertaken. This will require international collaboration and cooperation.
- Information to track and identify shifts in patterns of trade coming into the Great Lakes should be compiled and maintained on an annual basis.
- Increased resources are needed to support aquatic invasion science research, to advance our understanding of the invasion process, the development of reliable risk assessment models, and the ability to identify and evaluate potential future invaders.
- Genetic tools to identify relationships among source communities and newly established communities should be emphasized. This is perhaps the best tool we have to demonstrate source-donor relationships.
- Although the ballast tank vector remains the highest prevention priority, increased resources should be directed towards other vectors, such as aquaculture, the bait industry, and the aquarium industry.
- The barrier between the Mississippi River and the Great Lakes should be maintained and upgraded to prevent movement of exotic species between both ecosystems.
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