Coral reefs ecosystem
Coral reefs ecosystem are marine ecosystem inhabited by various types of corals, namely hard corals (hermatipic, stony corals) or coral reefs, soft corals (ahermatipic, soft corals) ecosystem, and gorgonians.
In Indonesia, coral reefs can be divided into four types, namely fringing reefs / shore reefs, barrier reefs, patch reefs and atolls.
Coral reef ecosystem are very important for spawning and spawning as well as habitat for various marine biota associated with corals, such as reef fish, shrimp, shellfish (molluscs), and various other marine invertebrates.
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| Image of Acropora coral reef in Tokong Berlayar Island, Anambas Islands |
Data on the extent of coral reefs ecosystem in Indonesia vary in various libraries. Burke et al. (2002) and Spalding et al. (2001) stated that the area of coral reefs in Indonesia reached 51,000 km2 or 51% of the total area of coral reefs in Southeast Asia.
Other data states that Indonesia's coral reefs reach 75,000 km2 (Hutomo & Moosa 2005) or 85,000 km2 (Tomascik et al. 1997). However, only 6.5% of Indonesia's coral reefs ecosystem are still in very good condition, 22.5% in good condition, and the rest can be categorized as medium, not good to bad (Dutton et al. 2000).
Indonesia has a high diversity of coral reefs ecosystem, recorded around 590 species (82 genera) of hard coral, 210 species of soft coral, and 350 species of gorgonian (Hutomo & Moosa 2005). In addition, there are about 2,057 species of fauna that live in coral reefs, 97 of which are endemic to Indonesian waters.
Of the crustacean group, there are 1,400 species of Brachyura. From the mollusk group there were 1,500 types of gastropods (snails / snails) and 100 types of bivalves (clams). From the Echinoderms group, there are 91 types of crinoids (sea lilies), 87 asteroids (sea stars), and 142 types of holothurians (sea cucumbers).
Sponges / sponges (demospongia) consists of 830 species. There are 30 types of marine mammals consisting of whales, dolphins and dugongs. There are seven types of marine reptiles consisting of turtles and crocodiles. Seaweed (macro algae) consists of 196 types of green algae, 134 types of brown algae, and 452 types of red algae.
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| There are still many marine flora and fauna that have not been recorded in this data (Hutomo & Moosa 2005). Some examples of the distribution of stony coral species from field observations in Tanjung Merah, Bitung and North Sulawesi, were found as many as 165 species (Souhoka 2006), 56 species in South Lampung (Widinugraheni 1993), 43 species in Ambon Bay (Sutarna 1989), Kei Island Kecil, Maluku Tenggara 75 species (Sutarna 1990), and East Nusa Tenggara 298 species (Abrar et al. 2012). |