Article: An outline history of seagrass communities

The primary ecological role played by seagrasses results from their ability to modify the physical environment. Trapping and binding of nutrient-enriched sediments encourages deposit and suspension-feeding invertebrates. Leaves provide a substrate and shelter for flourishing populations of bacteria, algae, protozoans, coelenterates, molluscs, bryozoans, and echinoderms which in turn contribute CaCO3 to the sediment, forming strata with a good preservation potential. The seagrass community is best developed in tropical and subtropical regions, especially where alternative nutrient sources are limited.The geological history of seagrass communities is traced with the aid of foraminifera. Gradual encroachment of seagrasses into the sublittoral of the late Cretaceous or early Caenozoic was followed in the Miocene by a rapid dispersal of Thalassia and associated biota, arriving for the first time in the Caribbean and mid Pacific.