fresh oysters on the half shell

Oysters are a seafood delicacy that can aid local ecosystems in many ways. Recycling oyster shells is an important source of future oysters for food and natural diversity.

The small shellfish are water filtration powerhouses. Adult oysters can filter impurities from more than 2 gallons of water per hours and their reefs provide habitat for fish, shrimp, crabs, and other sea life while controlling erosion of surrounding shorelines.

They are also prolific reproducers. Adult oysters release millions of fertilized eggs in the summer months. During their development, young, free-swimming oysters may travel great distances from where they were originally released, but they need one vital component in order to survive: the shells of their ancestors.

Why It’s Important to Recycle Oyster Shells

The concept may sound strange, but in order to reach full maturity, young oysters must attach themselves to a hard substrate — ideally another oyster shell. If no suitable surface exists, the young oyster will die.

In areas where oysters have grown freely for generations, this is just another part of the circle of life. But waterways where oysters are harvested frequently for their meat have been faced with mounting oyster shortages because of a lack of empty shells and hard surfaces for young oysters to call home.

These shortages have kept popping up for more than 5 years, with Alabama shutting down its oyster season this year. Around the world, oyster harvests are being limited to preserve oyster populations. In New York City, the Billion Oyster Project is collecting shells from restaurants to rebuild 100 acres of oyster reefs by 2035. The city has already collected 1 million pounds of shells.

A growing number of coastal communities are setting up recycling programs to recover spent shells and reintroduce them to local waterways as natural habitats for the next generation of shellfish. Read on for the details.

Next page: How are oyster shells recycled?

By Mary Mazzoni

Mary is a lifelong vegetarian and enjoys outdoor activities like hiking, biking and relaxing in the park. When she’s not outside, she’s probably watching baseball. She is a former assistant editor for Earth911.