Biodiversity of the seagrass ecosystem

Most seagrass beds in Thai Waters are still abundant and important in terms of being habitats for the juvenile organisms and food sources for various aquatic animals, especially fish, shrimps and crabs. Not only small animals are earning benefits but also large aquatic animals such as sea turtles and dugongs. Seagrass beds are also diverse with phytoplankton, zooplankton, algae, and other small aquatic animals living in seagrass beds. These organisms play important roles in food chains of the ecosystem.

More than 95 species of benthic and infauna animals are found in seagrass beds in Thai Waters. Most of them are worms and mollusks i.e., Strombus canarium, Scapharca inaeguivalvis; shrimp and mantis shrimps i.e., Peneaus semisulcatus, Metapeneaus moyebi, Orlosquilla nepa; crabs, i.e., Portunus pelagicus, Portunus Sanguinolentus and Scylla serrata. Moreover, sea cucumbers (Holothuria scabra), sea stars, and other species are also found in seagrass beds. In some organisms, they spend some stages of their life such as juvenile stage or amateur stage inhabiting in seagrass beds but some species live in seagrass for entire life.

At least 67 species of fish can be found in the seagrass beds distributed in The Andaman Sea and the Gulf of Thailand. The dominant fish found in seagrass beds include the fish in the family Lethrinidea, Theraponidae, Lutjanidae. However, at least 7 species of economic fish are found including Epinephelus coioides, Sillago maculate, Lethrius lentjan, Scromberoides lysan, Valamugil cunnesius, Valamugi buchanani, Liza subviridis, and Stolephorus spp.) (Satapoomin and Poovachiranon, 1997). There is a closed connection among fish living in seagrass beds, mangroves and coral reefs. Several fishes that inhabit in coral reefs or mangroves are found in seagrass for their feeding .

Figure  Example of organisms found in seagrass beds