"The Great Lakes are host to thousands of native fishes, invertebrates, plants, and other species that not only provide recreational and economic value to the region, but also hold important ecological value. However, with over 180 documented aquatic nonindigenous species (ANS) and an apparent introduction rate estimated at 1.3-1.8 species·year*¹ through 2006, the Great Lakes basin is considered one of the most heavily invaded aquatic systems in the world (Mills et al. 1993, Ricciardi 2006, GLRI Task Force 2010). Some of these nonindigenous species may become invasive (i.e. "species whose introduction does or is likely to cause economic or environmental harm or harm to human health" (Executive Order 13112, 1999)) and threaten the ecological and/or socio-economic value of the Great Lakes. In contrast, other nonindigenous species are capable of contributing value to the Great Lakes. Pacific salmonids, for instance, are stocked annually by the millions to help support the Great Lakes' multi-billion dollar fishery (Kocik and Jones 1999, USFWS/GLFC 2010, USACE 2012a)"--Introduction.

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