Farmed oysters and other shellfish feed by moving water in and out through gills, which capture solid particles from the water. The animal consumes the solid particles and expels clearer, unused water.Through the simple act of feeding, oysters remove excess nutrients, sediment, and other particles from waterways, which clears the way for sunlight to benefit entire ecosystems.

Through feeding, oysters also absorb nitrogen from the water around them. Harvested oysters bring this excess nitrogen with them, clearing it from the ecosystem.Through their waste matter, oysters also help to cycle nitrogen back into the water, where it is then used to sustain other organisms, such as phytoplankton.

Some atmospheric carbon dioxide ends up dissolved in waterways. Oysters take in, store, and process this carbon, some of which is expelled through waste and turned into sediment.This oyster-processed carbon then contributes to the lives of many species of deposit-feeding organisms.

Many aquatic life forms need a hard, stable floor to which they can attach and thrive.The presence of oysters and other shellfish contributes to a solid bottom substrate, which is a perfect environment for mussels, barnacles, anemones, and other organisms to inhabit. Various species of fish also use oyster reefs to lay eggs and protect themselves from predators.

Oyster reefs act as natural breakwaters, dissipating wave energy and protecting coastlines from erosion.