Oyster Facts


  • Native to the Chesapeake Bay, the Eastern or American Oyster (Crassostrea virginica) can be found from Maine to Texas.
  • While the species is the same, the flavor profile, or merrier, can differ based on where the oysters are grown. The Chesapeake Bay oyster’s salty-sweet buttery flavor is a reflection of the area’s rich and briny water.
  • Oysters are low in calories, low in fat and a good source of protein. They are naturally high in many essential vitamins and minerals including iron, omega 3 fatty acids, vitamins A, E, and C, zinc, iron, calcium, selenium, and vitamin B12.
  • An old myth specifies the best time to eat oysters is during months that contain an “R” (September through April) and to avoid eating oysters in months that do not contain an “R” (May through August). Today, thanks to modern refrigeration and the development of new breeds of oysters that do not reproduce in the summer, oysters are fine to eat any time.
  • Eating oysters supports local watermen and oyster farms, as well as helps improve the Bay’s health. ORP’s Shell Recycling Alliance collects and recycles oyster shell from 300 participating restaurants and seafood service centers. The recycled shell, with baby oysters attached, are planted on reefs. Each recycled shell can return 10 new oysters to the Chesapeake Bay.
Oysters 101 one

A clump of oysters in the Little Choptank River.

  • The Greeks envisioned their goddess of love, Aphrodite, springing forth from the sea on an oyster shell and giving birth to Eros, from which the word “aphrodisiac” was born.
  • Oystershave the ability to change They are born with organs that can produce both semen and eggs. Although they can only produce only sperm, or only eggs at any time, they have the ability to change which they produce.
  • When oyster larvae (baby oysters) attached themselves to a hard material, like an oyster shell, they are called “spat.” Wild and hatchery-raised oysters prefer to attach to other oyster shells as they grow.
  • Oysters typically grow up to an inch per year. Usually oysters will grow faster in higher salinity areas than in lower salinity area.
Oysters 101 five

Samples of Eastern or American oysters.

  • Oyster reefs create a habitat for a multitude of marine life, including two of Maryland’s iconic species, the Blue Crab and Striped Bass
  • Excess nutrients and sediment from human activities negatively affect water quality by disrupting the balance needed to support a healthy ecosystem. Science has shown that oysters can play a role in restoring water quality because of their filter-feeding capabilities.
  • Oysters remove nutrients from the water by consuming and absorbing the nitrogen and phosphorus from what they eat (algae, for the most part) into their tissue and shells. They then deposit the organic particles making it more accessible to bacteria that convert bioavailable nitrogen to nitrogen gas via denitrification. Oysters also remove sediment particles from the water column during filter-feeding by depositing them on the bottom, which helps clear the water
  • A healthy, adult oyster can filter up to 50 gallons of water a day.
  • The Chesapeake Bay loses an estimated 2,600 acres of oyster reefs annually due to silt and sediments that cover them.
Oysters 101 three

Oysters growing on rock in Maryland’s Little Choptank River.

  • In 2009 President Barack Obama declared the Chesapeake Bay a “national treasure” and signed a federal order to restore oysters in 10 tributaries by 2025.
  • Recent scientific advances make it possible to produce billions of baby oysters each year, that are used to regenerate existing reefs, establish new ones and fuel the rapidly expanding aquaculture industry.
  • Hatchery seed is providing watermen and oyster farmers with harvest and economic stability while supporting the demand for sustainable seafood without adding pressure on the wild population.
  • Oysters protect our water, our heritage and our economy. For every $1 donated, approximately 100 oysters are planted. At ORP, 95 percent of all donations go directly to restoration, so every dollar matters