Bay grasses are plants that grow underwater. They are found in the shallow waters of the Chesapeake Bay and its streams, creeks and rivers. Bay grasses are also known as submerged aquatic vegetation or SAV. Bay grasses are a critical part of the Chesapeake Bay ecosystem. They provide underwater life with food and habitat, absorb nutrients, trap sediment, reduce erosion, and add oxygen to the water. Bay grasses are an excellent measure of the Bay’s overall condition because their health is closely linked with the Bay’s health. Pollution and extreme weather conditions are two factors that hinder bay grass growth. Improving water clarity is the most important part of bay grass restoration because bay grasses need sunlight to grow.