Chapter 4 Habitats
Algal blooms tend to occur when nutrient loads are not flushed because water flow is slow, water depths are low, and where mixing of the water column is reduced due to salinity and/or temperature gradients. Blue-green algae are usually associated with blooms in freshwater areas, and they have lower nutritional value to aquatic life than other types of algae. Dinoflagellates and other flagellated algae are usually responsible for algal blooms in estuarine and marine waters (Smayda 1989, NC Sea Grant 1997, Mallin et al. 2000b, NCDEQ 2021) . Some dinoflagellate species release toxic chemicals into the water column that harm fish and shellfish by affecting their nervous systems and paralyzing their respiratory systems (Tyler 1989, NCDEQ 2021) . Invasive Species . Foreign organisms in the discharge of ships’ ballast water at or near ports have resulted in the introduction and spread of nonnative invertebrate animals, algae, bacteria, and dinoflagellates (NCDEQ 2021) . Removal of dams and other passage barriers (locks) creates a pathway for nonnative species to move between freshwaters and brackish water environments, including movement upstream from brackish estuarine waters into river drainages as a saltwater wedge expands into freshwaters. The water mold Aphanomyces invadans is an invasive fungal pathogen that infects schooling fish species in low-salinity or freshwater and is suspected to have been introduced to the United States through another infected invasive species, the Northern Snakehead Fish (Blazer et al. 2002, NCDEQ 2021 ). The Australian Spotted Jellyfish can consume large quantities of plankton, eggs, and larvae in the water column and has been found in Bogue Sound and at Sunset Beach. The invasion of the Indo-Pacific lionfish in marine waters off North Carolina will likely impact estuarine aquatic communities through direct predation, competition, and overcrowding (NCDEQ 2021). There are also a number of noxious weeds that can be found in fresh and moderately brackish waters of slow-moving streams or waters protected from strong tidal currents and wave action. These include Eurasian Watermilfoil, Alligator Weed, and the Common Reed (see Appendix E for scientific names). The most troublesome species in low salinity, estuarine waters is Eurasian Watermilfoil (NCDEQ 2021) . Climate Change . Climate change will influence water quality, salinity, water depth, and temperature, which will in turn alter fish distribution and abundance (NCDEQ 2021) . There are expected increases in temperature and sea level for the immediate future based on a history of measurement data (Bin et al. 2007, Bin 2008, UNCW 2008, NCDEQ 2021) . Long-term changes in temperature and salinity suggest expansion of some species at the expense of others. There is also a predicted increase in storm events and other extreme weather conditions (i.e., drought) (NCDEQ 2021) . If sea level rises too quickly, natural coastal wetland accretion processes may not keep pace. Increasing frequencies and severity of coastal storms and storm surge will contribute to inlet breaches along barrier islands and lead to significant increases in salinities in Pamlico Soundand
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2025 NC Wildlife Action Plan
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