4.2 Aquatic Communities
4.2.5.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help defne short- and long-term conservation actions and recommendations. Aquatic systems have been under threat from a variety of perturbations in the past and many of those continue today. Conversion of land, both from forest to agriculture or silviculture, as well as from development projects, continues to threaten stream integrity resulting in increased sediment, bank erosion, and stormwater runof containing sediment and other potentially toxic materials. Considering current conditions in these systems, climate change is likely to have a synergistic efect with other threats that are of more immediate concern. A comparison of climate-related impacts to other threats is not included in this description because the NCNHP vulnerability assessments completed in 2010 did not include warmwa- ter systems as a community type. However, development, sediment and erosion, and pollu- tion are primary concerns, and results similar to the comparison for coolwater systems are expected (see Table 4.7 in Section 4.2.4). 4.2.5.5 Impacts to Wildlife Appendix G includes a list of species for which there are knowledge gap and management concern priorities. Appendix H includes SGCN that use warmwater streams. Fish can regulate their metabolism by changing location or congregating in response to thermal stratifcation that can occur seasonally or in response to artifcial thermal efuent (e.g., power plant discharge) (Reynolds and Casterline 1979; Peterson and Rabeni 1996) . Te temperature tolerance range of aquatic species can be specifc and the availability of warm waters that do not exceed tolerances can be a limiting factor in determining where species can fnd appropriate habitat, especially as average water temperatures experience warming trends (DeWan et al. 2010) . Even though they may not normally congregate during the winter, fsh may do so if warmer water is available instead of the traditionally colder water. Tis will result in increased vulnerability to predation and exposure to disease (Peterson and Rabeni 1996) . Many large warmwater rivers in the Piedmont and Coastal Plain ecoregions have hydro- power dams that regulate daily fow. Tese fuctuations can result in streambed and bank instability, scouring, erosion, and turbidity and can discourage riparian vegetation and streambed vegetation and algal growth (Walburg et al. 1983; Cushman 1985; Peterson and Rabeni 1996) . Tese impacts may contribute to a reduction in macroinvertebrate prey and loss of emer- gent and submerged vegetation, which will afect fsh productivity (Peterson and Rabeni 1996) . Te loss of vegetated and edge of channel habitats that serve as nursery areas for young fsh can impact age classes, and species that have low reproduction rates may experience loss of entire years of reproductive potential (Peterson and Rabeni 1996) .
243
2015 NC Wildlife Action Plan
Made with FlippingBook - professional solution for displaying marketing and sales documents online