Chapter 3 North Carolina Species
3.9.5 Management Needs Captive propagation and reintroduction of imperiled snails continue to be explored as a conservation measure. Techniques include rearing snails in captivity for subsequent release into known historic range or other refugia. Other techniques may include relocation or translocation of eggs, juveniles, or adults from viable populations to augment extant populations or establish new populations in suitable habitats. The NCWRC has successfully propagated Magnificent Ramshorn, a federal-listed endangered aquatic snail, and released captive bred adults to freshwater pond habitat within its home range in the Coastal Plain ecoregion. None of these approaches are without risks, such as reduction of genetic material and inbreeding, introduction of disease from individuals released into the wild, and loss of species held captive from human error or equipment failure (Snyder et al. 1996; USFWS 2000; Lysne et al. 2008) , but these must be balanced against the extremity of threat to both the species in question and the taxon as a whole . 3.9.6 Threats and Problems Chapter 5 describes 11 categories of threats the Snail Taxa Team considered during the evaluation and ranking process to identify SGCN. Information about the expected scope and severity of the impacts from these threats is available in Appendix 5, as noted below. Since there is a significant lack of information about aquatic and land snails in the state, the evaluation results for Metric 9 are largely qualitative and do not adequately assess anticipated impacts from threats for nearly all species considered by the Taxa Team. The evaluation results indicate the threats most likely to create significant impacts on populations of Magnificent Ramshorn and Greenfield Ramshorn in North Carolina over the next 10 years include:
• Residential and commercial development (see Appendix 5, Table 5.3-1) • Agriculture and aquaculture (see Appendix 5, Table 5.4-1) • Transportation and service corridors (see Appendix 5, Table 5.6-1) • Natural system modifications (see Appendix 5, Table 5.9-1) • Pollution (see Appendix 5, Table 5.11-1) • Climate change and severe weather (see Appendix 5, Table 5.12-1)
Acid deposition from air pollution can affect soil calcium levels, which in turn may affect snails. An association has been made between snail abundance and diversity and availability of calcium (from soil cations, detritus, plants) for regulation of bodily processes, reproduction, and shell building (Burch 1962; Fournie et al. 1984; Nekola 1999; Nekola and Smith 1999; Kalisz and Powell 2003; Hickman et al. 2003; Dourson 2013) . Snails play a critical role in concentrating calcium (in shells) which then becomes available to species in higher trophic levels, especially birds that need calcium for egg
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2025 NC Wildlife Action Plan
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