3.4 Crayfshes
populations is not known. Measures to address impacts from these introduced populations should be considered for the drainages where they have been introduced. Te Red Swamp Crawfsh is native to the lower Mississippi River Basin but is currently being raised as an aquaculture product in North Carolina. In 2012, fve aquaculture farms in North Carolina produced approximately 8,685 pounds of this crayfsh for consumption. It has been introduced to waters throughout the state and could pose a signifcant threat to native crayfsh populations. Te Kentucky River Crayfsh has recently been introduced to western North Carolina where it has been found in the Little Tennessee River Basin. Te Rusty Crayfsh is another introduced species found in the Broad and Catawba River basins. Both species could pose a signifcant threat to native crayfsh populations. Te Virile Crayfsh has been introduced in the Roanoke, Catawba, and Broad River basins and its efect on native crayfsh populations is unknown. Long-term monitoring of the spread of this crayfsh should be a high priority. 3.4.6 Threats and Problems Over the next several decades, invasive species are predicted to increase extinction rates of native species signifcantly (Lodge et al. 2000a; Shochat et al. 2010) . Introduced nonnative cray- fsh (i.e., the Coosa River Spiny, Kentucky River, Rusty, and Virile crayfshes, and the Red Swamp Crawfsh) are a primary threat, followed by habitat loss, degradation, or alteration (Taylor et al. 2007; Simmons and Fraley 2010) . Nonnative crayfsh have cleared streams of vegetation, eliminated insect larvae (macrobenthics) and other native organisms through predation, and contributed to problems with turbidity in otherwise clear water in small streams (Davidson et al. 2010) . Although eradication or control of invasive species can be economically more expensive than the cost of prevention, measures or programs that address invasive species proactively are usually underfunded (Leung et al. 2002; Allendorf and Lunquist 2003; Ricciardi et al. 2011; Withrow et al. 2015) . Problems and uncertainty with taxonomy for numerous species need to be addressed in order to better understand abundance and distribution better and to develop conservation measures for native species. Research related to these threats and their impacts on certain species was ranked as a high priority. Chapter 5 describes 11 categories of threats the Taxa Team considered during the evalu- ation and ranking of priority species, and provides information about the expected scope and severity of their impacts to wildlife in North Carolina (see Appendix G). Results of Metric 9 evaluations indicate the threats most likely to create signifcant impacts to cray- fsh populations in North Carolina over the next 10 years include the following:
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2015 NC Wildlife Action Plan
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