The functions of nursery areas are most threatened by nonpoint sources of pollution and development on land near nursery areas. Information on the coverage of submerged aquatic vegetation is limited and, although there is no baseline data available on the extent of SAV, anecdotal information indicates that there may have been large losses of SAV from historic levels, particularly in the rivers, creeks, and western sounds. Threats to SAV habitat include direct physical disturbance such as dredging, mechanical clam harvesting, and changes in water quality. Submerged aquatic vegetation is also sensitive to declines in water transparency. One species of SAV, eelgrass, may be declining rapidly as a result of high levels of nitrate in the water.
Anadromous fish live in the oceans but migrate up freshwater rivers to spawn.
The spawning success of anadromous fish has declined as evidenced by reduced adult landings and reduced juvenile abundance. Recently, there has been a high level of concern for striped bass which spawn in the Roanoke River. It has been established that the success of their spawning is impaired by changes in water flows and the water quality impacts that result from discharges from the Roanoke Rapids dam. Shellfish Bed s Clams, oysters, and bay scallops have supported important fisheries throughout the history of North Carolina commercial fishing. However, the productivity of these shellfish beds has declined as indicated by landings data.