Invasive Species Policy at the Regional Level: A Multiple Weak Links Problem

Policy is used to prevent the introduction and spread of invasive species. For aquatic invasive species that can easily cross political boundaries, regional policies are needed. A weak link problem occurs when regulations of individual jurisdictions increase the region-wide risk of species introductions, especially in adjacent jurisdictions. Such cross-jurisdictional weak links may be compounded by another sort of weak link within jurisdictions: inconsistent regulation among multiple vectors that may introduce the same species. We used crayfish as a model system to study regulations for anglers, bait dealers, the pet trade, and aquaculture across the Great Lakes region. We identified a continuum of regulations ranging from no regulations to those that prohibit all use of crayfish. Furthermore, regulations differed depending on state and vector. Many states had regulations that specifically targeted the invasive rusty crayfish (Orconectes rusticus). However, these regulations were enacted reactively only after rusty crayfish had become established in the state. The lack of regulatory consistency among the Great Lakes jurisdictions is creating a multiple weak links problem and making success unlikely in efforts to slow the spread of crayfishes and other invasive species throughout the region.