control activities that depend on continued commitment and resources as well as on development 
of successful, targeted control mechanisms (Simberloff, 2003; Mack et al., 2000). Focusing on 
post-entry activities also can result in a significant time lag between identification of the invasion 
and implementation of control mechanisms—a delay that could result in extensive spread and 
establishment of invasive species (Ruiz and Carlton, 2003). In addition, increased invasions by 
numerous different species mean that various invasive-species management techniques are 
needed, and with limited resources, only a fraction of these management actions can be 
implemented (Ruiz and Carlton, 2003). Thus, prevention activities are key tools for successfully 
addressing invasive species, and states with limited resources may maximize the use of scarce 
invasive-species dollars by investing in prevention efforts. 
Numerous strategies and measures may be used to prevent the establishment of 
potentially harmful AIS, including mapping and/or surveys to identify and mitigate invasive 
species threats, regulation of certain species (e.g., introduction, import, or release requirements), 
quarantines, EDRR protocols and emergency powers to quickly identify and address new 
infestations, and education to increase public awareness regarding particular species and/or 
pathways. Another important prevention tool for invasive species managers is the Hazard 
Analysis and Critical Control Points (HACCP) planning framework. As a part of the HACCP 
planning process, natural resource managers identify potential invasive species and possible 
points of entry that could result from management activities. Managers also focus on specific 
pathways and develop best management practices to prevent these species from being 
introduced. This planning framework helps managers assess risk and make more strategic 
decisions (USFWS, 2005). 
Many state AIS prevention efforts are specific to species that have been identified as 
imminent threats' while other activities are focused on managing and responding to common 
AIS pathways such as ballast water, recreational boating, water gardening, or aquaculture. For 
example, the New Hampshire Department of Environmental Service’s Weed Watcher Program 
trains volunteers to inspect recreational boats and other recreation-related gear to prevent 
introduction of aquatic invasive plants. Often, states will conduct a combination of prevention 
measures to address species or pathways. The Maryland Department of Natural Resources - 
Fisheries Service, for example, seeks to prevent the spread of snakeheads by circulating posters 
that ask anglers to kill and report all snakeheads, compiling regional data for captures in the 
Potomac River, and annual monitoring that includes seine, electrofishing, and gillnet surveys. 
Maine’s Department of Environmental Protection and Department of Inland Fisheries and 
Wildlife conduct aquatic invasive plant prevention along common pathways. The agencies 
jointly inspect watercraft, trailers, and outboard motors at or near the state borders and at boat 
2-13 
