4.2 Aquatic Communities
Potential increased air temperatures will infuence water temperatures and can lead to algal blooms in aquatic systems, which in turn diminishes stream oxygen availability. Te increased water temperature alone can cause a decline in DO and any decline in DO can lead to fsh kills, whether as a direct result of increased water temperature or as a second- ary efect of algal blooms. Tis phenomenon may be increasingly expressed within reser- voirs on large Piedmont rivers (DeWan et al. 2010; Band and Salvesen 2009) . 4.2.10.4 Climate Change Compared to Other Threats Comparing climate change to other ecosystem threats can help defne short- and long-term conservation actions and recommendations. Sea level rise already impacts large rivers at their terminus along the Atlantic coast. Other climate change impacts may not be as severe a threat, but a combination of synergistic efects with other existing conditions could stress these systems to the point where several species are unable to persist. Table 4.11 provides a review of expected climate change impacts in order of importance in comparison with other types of threats. 4.2.10.5 Impacts to Wildlife Appendix G includes a list of SGCN and other priority species for which there are knowl- edge gap and management concern priorities. Appendix H identifes SGCN that use large river communities. Weather extremes (such as drought, foods, tropical depressions, hurricanes) that are expected to be amplifed by climate change can have profound efects on fshery produc- tion in large Coastal Plain rivers. Chronically warmer temperatures and lower DO levels will increase stress on aquatic organisms and disrupt trophic relationships. Aquatic species could experience shifts in their range or distribution and sensitive species may experience decline or extirpation due to changes in water quality and habitat. Aquatic species are particularly sensitive to temperature cues and recent research has shown that many species of freshwater mussels may already be living at the upper thermal tolerances of their early life stages (glochidia and juveniles) (Pandolfo et al. 2010) . Because of the link between freshwater mussels and fsh, phenological disruptions are a possibility, but exact mechanisms or efects are not well understood. Freshwater mussel larvae (glochidia) are dependent on a host fsh for transformation into juveniles. Host fsh species are known for some mussel species, yet unknown for others. Temperature cues play a large role in the release of glochidia from female mussels and also in the movement and migrations of fsh.
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2015 NC Wildlife Action Plan
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