Chapter 4 Habitats
Invasive plants in the riparian area can have negative impacts on stream systems by creating a monoculture with poor nutrient inputs, reducing bank stability and reducing shading (warmer stream temperatures). Alligator Weed creates floating mats that disrupt DO levels. Asian Dayflower, Hydrilla, Water Hyacinth, and Giant Salvinia could pose more of a threat to these systems with a warmer climate. 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 a disease vector. The Basket Clam is an exotic species found in aquatic systems throughout the state. However, its effects on native mussels are largely unknown. Mystery Snails are established downstream of Falls Lake (Neuse River basin) and have been collected in reservoirs on the Catawba, Yadkin-Pee Dee, Roanoke, and Neuse rivers and in the Pee Dee, and Neuse River proper, between Tillery and Blewett Falls reservoirs. These large snails feed primarily on algae and diatoms and have been known to clog water intake screens in other parts of the United States, but effects on native mollusks are largely unknown. They have the potential to serve as vectors for the transmission of parasites and diseases. Flathead Catfish are a concern because of direct predation on native species. Climate Impacts. Very few specific climate change-related impacts have been identified, and the rare species and their habitats are expected to persist. Climate change is likely to have a synergistic effect with other, more immediate concerns in these 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. Sea level rise is likely to impact the lower reaches of large Coastal Plain rivers because inundation is predicted to varying degrees. The combined increase of inland flooding due to higher precipitation events with elevated sea levels will exacerbate coastal inundation. Saltwater intrusion into currently freshwater streams will shift the transition from freshwater to brackish water farther upstream. As the chemical composition of currently freshwater systems changes, associated freshwater wetlands could be converted to salt marshes as saltwater moves farther upstream into these rivers (Band and Salvesen 2009; USEPA 2010; Bakke 2008; Burkett et al. 2000). Changes in salinity and tidal influence will likely change the overall species composition in these systems. Recent surveys of tributaries to the Albemarle Sound, Tar River, and Neuse River found Dark Falsemussel ( Mytilopsis leucophaeta ), a brackish water bivalve, is present farther upstream than has occurred historically. Drought conditions over the past several years have required many municipalities to evaluate their water supply and capacity to meet demand. Residential and commercial growth in urban areas generates new demands for water supplies. An increase in the number of proposed reservoirs is a potential consequence of reduced water supply and increased demand.
Potential increased air temperatures will influence water temperatures and can lead to algal blooms in aquatic systems, which in turn diminishes stream oxygen availability. The increased
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2025 NC Wildlife Action Plan
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