A risk assessment of potential Great Lakes aquatic invaders

Introduced species have the potential for both ecological and socioeconomic effects. Once established, these species can be nearly impossible to eradicate (Hobbs & Humphries 1995). In the few successful eradication efforts, the cost has been substantial (Simberloff 2003). Managing spread and controlling for impact are also costly (Leung et al. 2002). At least 31% nonindigenous species established in the Great Lakes have significant impacts (Sturtevant et al. 2014). The most economically and practically effective strategy is therefore to prevent species introduction in the first place (Lodge et al. 2006). As a means of prioritizing management efforts, risk assessment tools that consider vectors and pathways of introduction, species life history traits, habitat suitability, historical patterns of invasion, impacts realized in other invaded regions have become commonly implemented (Gordon et al. 2012, Keller et al. 2009). In order to accurately predict risk, a thorough understanding of these potentially introduced species is needed (Keller et al. 2007b, Springborn et al. 2011—but see Simberloff 2003). However, species and pathway information can also be scarce or diffuse (e.g., 95/156 species assessed as “not enough known” in USEPA 2008).