Marine Plants in Coral Reef Ecosystems of Southeast Asia
The coral reef ecosystem is a collection of diverse species that interact with each other and with the physical environment. The latitudinal distribution of coral reef ecosystems in the oceans (geographical distribution) is determined by the seawater temperature, which influences the reproduction and growth of hermatypic corals − the main component of the ecosystem. As so, coral reefs only occupy the tropical and subtropical zones. The vertical distribution (into depth) is limited by light. Sun light is the main energy source for this ecosystem, which is produced through photosynthesis of symbiotic microalgae − zooxanthellae living in corals, macroalgae, seagrasses and phytoplankton. Therefore, hermatypic corals are able to win in competitive struggle for the substrata and resources with other authotrophic organisms even under light about 1% of the surface photosynthetically active radiation (PAR0). The hard substratum for the majority of recent coral reefs is limestone basis, which is formed from remnants of historical reefs (fossil) appeared on the earth in the middle Triassic period (225−200 million years ago). The other hard substrata colonized by hermatypic corals are underwater rocks and stones, which will further form coral reefs. Moreover, coral reef can also be built on the basis of artificial substrata (e.g. oil towers or underwater constructions of mariculture farms in tropical regions of the oceans) (Titlyanov, Titlyanova, 2012a). The main difference between coral reefs and other underwater ecosystems is the formation of hard substratum, which is based on hermatypic coral colonies dying off and subsequent colonization by animals including corals and seaweeds. Coral reefs are the most diverse ecosystem and provide the largest primary production among all the underwater ecosystems on the coastal shelf. They occupy less than 0.1% of the world’s ocean surface, but provide habitat and refuge for 25% of all marine organisms, including fish, mollusks, wor
