Water Column (NOTE: Map not currently available. Work is underway to restore map functionality.) The water column is the link between all other fish habitat types and can be found in nearly every body of water. Function of Water Column Habitat The water column connects all habitat types. Water column habitat is critical for fish movement between other habitats. The water column allows sunlight to reach aquatic plants and alage, it allows oxygen and other essential dissolved nutrients to be delivered to aquatic plants and animals, and it provides a medium for all aquatic organisms to live. How Fish Use Water Column Habitat The water column is important to all types of fish but water column health is especially important for pelagic species (those fish that live at or near the surface of the water) such as river herring, Atlantic menhaden and blue fish. The water column provides transport for fish eggs and larvae from spawning grounds to nursery and foraging areas. All fish use the water column to forage and search for food. Highly Associated Species River Herring Atlantic Menhaden Bluefish Threats to Water Column Habitat Water quality is the most important factor affecting water column health. Runoff after rainfall can deliver chemicals, excess nutrients, and other pollutants into the water column. Loss of shoreline vegetation (buffers) increases turbidity, causing fish gills to become clogged and burial of other aquatic species. Conversion of natural areas to agriculture and urban development increases runoff and sedimentation affecting both water quality and clarity. Alteration of natural water flow by dams, ditches, roads and culverts impact fish movement. Important Facts The north-flowing Gulf Stream and the south-flowing Virginia Coastal Labrador Current converge off of Cape Hatteras, transporting a high diversity of temperate and subtropical fish into North Carolina waters. Because of this and the large and varied types of waterbodies, North Carolina supports an exceptionally diverse and productive fish community. Declines in water quality are closely associated with harmful algal blooms and fish kills. Water column health has a direct effect on the health of all other habitats in North Carolina.