Chapter 5 Threats
Global sea level has increased 20 to 23 cm (8 to 9 inches) since 1880 at a rate of 0.114 to 0.14 cm (0.045 to 0.055 inches) of rise per year to 1993. From 1993 to 2016, the rate of rise doubled to 0.28 cm (0.11 inches) per year, equating to an 8 cm (3 inch) rise (Sweet et al. 2017) . Sea level rise along the North Carolina coast is effectively three to four times the global rate due to the Atlantic Meridional Overturning Current along the northeast Atlantic Coast. The associated low- pressure conditions of this current result in increased sea level (Sallenger et al. 2012) . Sea level is likely to rise by up to almost 1.5 feet on the Atlantic Coast by 2050 (Sweet et. Al 2022) . According to vulnerability assessments (Boruff et al. 2005; Sallenger et al. 2012) , North Carolina’s coastline is one of the areas considered to have significant vulnerability to SLR. A report by the NC Coastal Resources Commission’s Science Panel on Coastal Hazards (NCDCM 2015) notes both geological and tide gauge data provide evidence there is more land subsidence to the north of Cape Lookout than to the south. This contributes to higher measured rates of SLR along the state’s northeastern coast (NCDCM 2015) . The Science Panel’s report compares the range of estimated sea level rise over a 30-year period based on three projection scenarios. The results show the highest and lowest potential increase in mean sea level varies from 2.7 inches at Duck (northernmost area) to 4.5 inches at Southpoint (southernmost area) (NCDCM 2015) . This variability is evidence of the uncertainty in predictions, especially at longer time scales, and the spatial differences along the state’s coast. Two of the greatest threats posed by SLR to fish and wildlife in North Carolina are loss of marsh and wetland habitats because of erosion and flooding, and the expected increase in salinity of coastal aquifers, freshwater drainage basins, and estuarine systems because of saltwater intrusion (Neumann and Hearty 1996) . DeWan et al. (2010) note that coastal habitats, such as maritime forests and shrub communities, estuarine communities, tidal swamp forests and wetlands, and beach and dune habitats, will be the most susceptible habitats to the effects of SLR. Saltwater intrusion into freshwater aquifers and drainage basins can threaten the biodiversity of freshwater tidal marshes and contaminate municipal, industrial, and agricultural water supplies (Marion et al. 2014; Bear et al. 1999) . Connectivity between habitats and modified landscapes will become even more important as species are forced to shift their ranges inland because vegetation is converted to open water or dies off from the influence of higher salinity of surface waters. Migratory fishes and the freshwater stream ecosystems they use for portions of their life cycle will be adversely affected by saltwater intrusion, especially if upstream freshwaters where the salt wedge has not historically been recorded become brackish (Roessig et al. 2004; Love et al. 2008). Movement upstream to freshwater refugia can be impeded if there are barriers to movement, such as dams and hydraulic conveyances under roadways (i.e., culverts and pipes). Sea turtles and beach-nesting shorebirds will be impacted by SLR through loss of nesting habitats by erosion and inundation and flooding of nests that result in egg mortality (Fuentes et al. 2010) .
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2025 NC Wildlife Action Plan
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