Chapter 4 Habitats
Invasive aquatic animal species such as Basket (Asian) Clams, Mystery Snails, Red Swamp Crayfish, and Nutria may have negative effects on native species through competition for space and resources and as disease vectors. The Basket Clam is an exotic species found in aquatic systems throughout the state; its effects on native mussels are largely unknown. Flathead Catfish are a concern because of direct predation on native species. Nutria are considered a serious pest species in the United States because they eat a variety of wetland and agricultural plants and their burrowing damages streambanks, impoundments, and drainage systems. Invasive plants in the riparian area can have negative impacts on stream systems by creating a monoculture (such as Japanese Knotweed) with poor nutrient inputs that reduces bank stability and shading and therefore, creates warmer stream temperatures. Alligator Weed creates floating mats that disrupt DO levels. Invasive aquatic plants such as Asian Dayflower, Hydrilla, Water Hyacinth, and Giant Salvinia could pose more of a threat to these systems with a warmer climate. Exotic insect pests may be a significant factor in river communities because they negatively impact native vegetation (Kenis et al. 2009, Diesburg et al. 2021) , thereby altering riparian habitats or allowing nonnative species to flourish. For instance, Hemlock Woolly Adelgid infestations have significantly impacted Eastern Hemlock forests in Appalachian forest riparian zones. Climate Impacts. Climate change is likely to have a synergistic effect with other, more impending threats to medium river systems, such as development and lack of/removal of riparian vegetation. Aquatic systems have been under threat from a variety of perturbations in the past and many of those continue today. Many of the water quality and water quantity impacts resulting from climate change are analogous to impacts from economic development and population growth in North Carolina. Climate change is predicted to alter seasonal precipitation patterns that can limit water supply. Growth and development, however, have been increasing and will continue to increase water supply demands. Historical stream flow patterns—already being altered due to rapid urbanization—are projected to be further altered due to climate change impacts. Potential changes in precipitation may have numerous and varied effects. Severe and prolonged droughts may decrease stream flow, decrease groundwater recharge, and increase evaporation, resulting in impacts to medium rivers. A decrease in overall summer precipitation will likely cause reduced water flows, which will contribute to warmer water temperatures and further stress water quality. This is particularly important in the context of seasonal droughts because during low-flow periods, nutrients may become concentrated and flush out of systems more slowly (DeWan et al. 2010; Karl et al. 2009; Band and Salvesen 2009; USEPA 2010) . Increased air temperatures may lead to increased water temperatures and potentially lower DO levels. Higher air and water temperatures can also lead to increased evaporation, which results in less flowing water available for aquatic species. Hot spells can have the same effect as overall increased air temperatures but on a much more acute scale. Algal blooms are possible in these
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2025 NC Wildlife Action Plan
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