Submerged Aquatic Vegetation, or SAV is an underwater garden for juvenile fish and small invertebrates and a barometer of water quality.
SAV produces oxygen and detritus that is exported to other habitats, and reduces moderate turbidity and turbulence. SAV is extremely dependent on clarity of the water column for its existence.
Fish use of SAV habitat
- Over 150 fish and invertebrate species are known to use SAV as adults or juveniles, of which about 30 are important commercial fishery species.
- SAV beds provide an excellent nursery area for many species, including blue crabs, red drum, pink shrimp, spotted seatrout, and gag.
- SAV blades provide a surface for post-larval shellfish attachment, especially bay scallops, and refuge for small fish like mummichogs, pipefish, and grass shrimp.
- Large predators, like flounders, rays, and red drum forage around SAV.
Some important facts
- There are about 200,000 acres of SAV in coastal North Carolina (See habitat mapping and monitoring).
- In North Carolina, SAV usually occurs in water less than 6 ft deep because of light limitations.
- Changes in SAV coverage can be a sensitive indicator of water quality.
How’s it doing?
While high-salinity SAV appears fairly stable, with some possible expansions in southern estuaries, large losses (50% or more) of low-salinity SAV have been reported in tributaries of western Pamlico, Albemarle, and Currituck Sounds since the 1970s. However, there are recent reports of SAV recovery in some of the low-salintiy areas. Reduced light availability from nutrient and sediment loading is thought to be the primary cause of losses. Research is needed, however, to quantify current distribution and cause of changes. See Threats to Habitat Index for more information
See SAV chapter of CHPP