|
2. Identification and Management of Other Vectors
While the majority of AIS that have invaded the Great Lakes over the past 50 years have arrived via international shipping, other mechanisms exist and are contributing to the problem. These mechanisms include the intentional and unintentional releases of 'aquarium' species, importation of live species for bait and for human consumption, and activities related to aquaculture. It is possible to identify the risk points and regulate each of these other vectors accordingly. Indeed, these vectors should be addressed in concert with the ballast water problem, since the introductions they may produce are no less irreversible. The Great Lakes Sea Grant Network is working closely with the aquaculture and bait industries on the problem of invasive species and has made some progress, especially in sensitizing these communities to the issue and in identifying best practices to reduce the threat. With the support of Great Lakes fishery agencies and the Great Lakes Fishery Commission, an interactive Environmental Assessment Protocol for Great Lakes Aquaculture (Brister and Kapuscinski 2002) has been posted on the web for reference by regulating agencies, fish farmers, and the public.
The Corps of Engineers has built a demonstration electrical barrier, activated 9 April 2002, in the Chicago Sanitary and Ship Canal. Originally constructed to prevent movement of round gobies from Lake Michigan to the Mississippi River System, this barrier has the potential, perhaps with augmentation, to prevent the invasion of the Great Lakes by Asian carps. However, there are no long-term provisions for operations, maintenance, monitoring and improving the barrier between the Great Lakes and Mississippi River ecosystems.
In addition, global warming will certainly affect the potential for species invasions by expanding (or contracting) the geographic range of ecosystems in climatically acceptable locations. For example, under some global warming scenarios, it would prove exceedingly difficult to prevent movement of southern species into the Great Lakes as the climate warms.
|
