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failures associated with inadequate pond hydroperi- od. Timing of heavy rains is also associated with egg laying (NatureServe 2009) in species such as bark- ing treefrog (Hyla gratiosa) and southern chorus frog (Pseucdacris nigrita), a subspecies of which is identi- fied as a priority species in North Carolina. A number of aquatic species will be sensitive to changes in hydrology and timing of flooding and drying events. For example, several darters are associated with fast flowing waters. Priority species include longhead darter (Percina macrocephala) and olive darter (P. squarnata), both of which prefer waters with moderate to high gradients. The former may already have been extirpated from the state (NatureServe 2009). Others species, such as Caro- lina darter (Etheostorna collis), prefer habitats char- acterized by low velocity currents. Some species are particularly sensitive to changes in stream flow (NatureServe 2009). For example beds in flowing areas of creeks appear to be essential habitat for the Cape Fear shiner (Notropis mekistocholas), a federally listed species limited to a single river basin. In the Little Tennessee River Basin, hydrologic regime had a significant effect on fish species assemblage over a ten -year period (1983 -1992) that had some of the highest and lowest flows over the previous 58 year period (Grossman et al. 1998). Virtually all river drainages in North Carolina are already impacted by erosion and sedimentation from timberlands, agricultural areas, and urban develop- ment activities (NC WAP). Seasonal increases in runoff under climate change have the potential to further increase nutrient and sediment loads impact- ing species such as shortnose sturgeon (Acipenser brevirostrum), which utilizes silt free cobble or boul- der bottom for spawning (NatureServe 2009). In Virginia, siltation was identified as a primary cause of decline for Roanoke bass (Ambloplites cavifrons) in the Upper Roanoke River Drainage (Burkhead and Jenkins 1991 in NatureServe 2009). Examples of other priority fish species that may be particularly sensitive to increased sedimentation include spotfin chub (Cyprinella monacha), lake chubsucker (Erimy- zon sucetta), Carolina darter (Eheostoma collis), and Cape Fear shiner (Notropis mekistocholas). Zamor and Grossman (2007) found that even low to moder- Photo: National Park Service, www. nps.gov 64 Chapter 3: Projected Impacts of Climate Change in North Carolina