Most seagrass species are located in silty or sandy sediments. Seagrasses tend to develop extensive underwater meadows that resemble fields of wheat. Seagrasses are believed to be derived from terrestrial plants which returned to the sea by gradual, progressive steps.
Flowers bloom and are pollinated underwater, often producing seeds in great quantities.
The growth of a seagrass meadow occurs by vegetative spread via extension of the rhizome and by the germination and growth of seedlings. The only remaining natural seagrass beds left in the Galveston Bay system grow in Christmas Bay. Seagrasses are important not only for the plant biomass produced but also for shoreline sediment stabilization and as a physically stable refuge and nursery ground for valuable fishes, shrimps, crabs, and their prey. This loss of over 450 hectares was attributed to direct and indirect effects of waterfront dredging for canal housing developments, wastewater discharges, storms, and unidentified point source pollution. Seagrass restoration has been viewed as a method for offsetting losses from natural phenomena such as storms and from human impacts such as dredging and coastal development on Galveston Island.