In the Indian River Lagoon there are over 170,000 submerged acres that are ideal for seagrass growth. However, there are only about 67,500 acres of seagrass in the lagoon. As recently as 1986, there were 86,000 acres of seagrass in the lagoon. The amount of seagrass is very important to the quality of the lagoon. Seagrass beds along with mangrove swamps are the base of the food web in the lagoon and local coastal waters.

     Seagrasses are not actually grasses but are more closely related to the lily family. They are a group of ecologically similar submerged, flowering plants. Seagrasses are adapted to live in shallow coastal waters and estuarine environments. They need clear, shallow, saline water to survive. Seagrass is comprised of shoots of three to five leaves connected by a horizontal stem beneath the surface of the sediment with thick fleshy roots. The horizontal stem allows them to withstand wave action. The leaves are supple and flat, round or ribbon-shaped. The common seagrasses in the Indian River Lagoon are shoal-grass, manatee-grass, star-grass, paddle-grass and some turtle grass.

     Seagrasses play many ecologically important roles. First, the leaves reduce the wave energy allowing sediment to settle out of the water column. Second, the roots and horizontal stem trap sediment and stabilize the bottom. Third, seagrasses are an important substrate for epiphytic algae and invertebrates. Over 600 epiphytic algae and 180 epiphytic invertebrates live on seagrass blades. Fourth, seagrass strips nutrients out of the water. This can be very important to the water quality in shallow areas. Fifth, seagrasses are highly productive primary producers. Sixth, seagrass is a food source for many animals. Studies show over 340 animals directly eat seagrass. Finally, seagrasses provide habitat, shelter, and nurseries for many commercially and ecologically important species.

     In the past 50 years Florida has lost a large portion of its seagrass beds. Dredge and fill activities, freshwater discharge, declining water quality, and boat prop scour are some of the main causes of this habitat loss. Dredge and fill operations are now closely monitored and are not allowed on seagrass beds. Prop and anchor scour can only be prevented by conscientious boaters. The main problem now is freshwater discharge and water quality.

On to Seagrass Identification