| Thalassia testudinum, which is the most common seagrass found in lagoons around Grand Cayman, influences sedimentation by baffling currents, binding sediment on the seafloor, and providing substrates for a diverse epiphytic biota. The epiphytes, formed largely of organisms that are <100 mum long, include at least three species of red alga, 72 species of foraminifera, 61 species of diatoms, and a broad array of other, less common skeletal organisms. These epiphytes are organized in three communities, with the basal diatom community being overlain by the coralline alga community, which is then overlain by a community composed of a variety of taxa. The final layer is the most diverse of the three communities. The red algae community, which is the most extensive, typically covers ∼75% of the leaf's surface. Few of these epiphytes are found in the sediment around the plants, suggesting that most were removed by current activity. |
