Oysters – More than Just Good Eats

Oysters do far more than end up on dinner plates. They clean the water, create habitat, and protect our shores, all while supporting local economies and healthy marine life. These hard-working shellfish have a big impact on the health and resilience of Long Island Sound.

Why Oysters Matter to Long Island Sound

• Filtering Water. Oysters act as natural water filters, improving water quality in Long Island Sound. Each oyster can filter up to 50 gallons of water every day, removing plankton, algae, and suspended particles. This natural cleaning process improves water clarity and reduces harmful algal blooms, creating better conditions for light-dependent species like eelgrass. Oysters also remove excess nitrogen, a major source of water pollution, by filtering it from the water and storing it in their tissues and shells. This natural uptake process reduces the amount of nitrogen available to fuel algal blooms and low-oxygen (hypoxic) zones that can harm marine life.
• Creating Habitat. Oysters grow together to form reefs that attract fish, crabs, and many other species seeking food and shelter. These reefs develop through a self-reinforcing cycle: adult oysters create hard surfaces where larvae can settle and grow, and as those young oysters mature, they add more structure for future generations. Over time, this process builds complex reef habitats that support higher biodiversity—the abundance of fish and invertebrates in an area increases with oyster density.
• Stabilizing Shorelines. Oyster reefs help stabilize coastal sediment, protecting it from erosion while also encouraging new sediment to build up along the shoreline. In nearshore areas, these reefs act as natural barriers that absorb wave energy and reduce flooding, helping to shield wetlands and other coastal habitats from storm impacts.
• Supporting Local Economies. Oysters are an important part of Long Island Sound’s maritime economy. The shellfishing industry produces millions of dollars in economic value and provides hundreds of jobs, while recreational shellfishing supports local communities and tourism.

While long-term population trends in oysters in the Sound have not been definitively established, a number of organizations are actively working to restore and build new oyster reefs. Cornell Cooperative Extension of Nassau County, City Island Oyster Reef, and Save the Sound are among the hands-on partners. The Long Island Sound Partnership, through its grant programs provides key funding support for reef restoration, shellfish-based water-quality projects, and community stewardship in the region.

How You Can Help Oyster Populations

• Help protect water quality at home. Reduce fertilizer use and manage stormwater runoff. Excess fertilizer can wash into Long Island Sound, causing algal blooms that lower oxygen levels. Oyster are stationary, so they can’t escape these conditions, putting them at risk.
• Dispose of waste properly. Never pour oil, chemicals, or litter into storm drains. Oysters are filter feeders, so anything in the water, including pollutants, can harm or even kill them.
• Buy local shellfish from sustainable farms and fisheries. Farmed oysters filter water just like wild reefs do. Buying locally not only supports your community but also helps improve water quality as the oysters grow.
• Get involved in local restoration projects or shoreline cleanups. Many oyster reef projects depend on volunteers. Participating in cleanups helps keep trash out of the Sound, protecting oysters and other marine life. Find volunteer opportunities here.