Bay grasses are part of the ecosystem

Just as on land, aquatic vegetation plays an important role in the ecosystem. In the Chesapeake Bay these plants are known as bay grasses or submerged aquatic vegetation (SAV).

Bay grasses are important to the fish, waterfowl and other animals that live in this large body of water. There are about 20 species of bay grasses. Their distribution is dependent on such factors as the salinity of the water, water clarity and depth. Plants such as wild celery and sage pondweed are more common at the mouth of the bay, where there is fresh water, while eelgrass and widgeon grass are found in the lower bay, where the water has much more salt.

Bay grasses are important as food and cover for many waterfowl, fish and shellfish. These grasses also filter sediment out of the water and take up nitrogen and phosphorus. This helps keep the water clear and prevents algal blooms. Bay grasses produce oxygen, essential for life.

These plants also help prevent erosion by helping to dissipate wave action and keep sediments in place.

The presence or absence of bay grasses is an important indicator of the health of a particular stretch of the bay. Having a diverse community of native grasses is a sign of a healthy ecosystem. Bay grasses are dependent on sunlight. When the water becomes cloudy, due to too much sediment loading, or when algal blooms occur; sunlight does not penetrate the depths enough to sustain these plants.

During a recent survey of the health of the bay, it was estimated that bay grasses declined approximately 20 percent between 2010 and 2011. The Chesapeake Bay initiative works to clean the water, remove nutrients and pollutants before they reach the bay, helping to stem the decline of this important vegetation. The bay program has many components, including working with landowners to reduce sediment and nutrients from entering the many streams and rivers in the bay watershed. Planting trees and meadow grasses near streams and wetlands filters water before it can enter these water bodies, and retrofitting sewage treatment facilities filters out nitrogen, phosphorous and other nutrients and pollutants.

Article by FCFCDB

Nature Notes for 1/20/2013