How oysters help treat polluted runoff

Why are oysters important?
North Carolina’s native Eastern Oyster (Crassostrea virginica) is a valuable ecological and economic resource for this region. Research has shown that our native oyster is a keystone species in North Carolina’s estuarine environment, and the oysters are so valued because of the three major functions they provide:

Filter: As filter-feeders oysters can filter between 25-50 gallons of water per day, removing pollutants, sediment, and excess algae from the water, thus greatly improving water quality. When oyster populations were at their peak, entire estuaries like the Pamlico Sound could be filtered and cleaned in a matter of days.

Food: Oysters are vital components of the estuarine food web, and they support a viable commercial and recreational fishery.

Fish Habitat: Oyster reefs provide habitat for many marine and estuarine species, and many of the species living on oyster reefs help support commercial and recreational fisheries. One healthy oyster reef can be home to more than an estimated 300 different organisms including southern flounder, shrimp, clams and blue crabs.

How are the oysters doing?
On Bradley Creek, all oyster shellfisheries have been closed since the 1940s due to widespread pollution and increasing human impact on the tidal creek ecosystem. Since the early 1900’s, the N.C. oyster population has declined an estimated 90 percent due to a variety of compounding factors – oyster diseases, habitat loss, pollution, declining water quality, and harvest pressure. However, over the past several years efforts to restore native oysters have increased significantly and annual oyster harvests have also increased.