The Coral Reef Ecosystem

This is a short article written on coral reef ecosystem for EKOMAR coffeetable book :).

"Coral reef ecosystem is the most diverse ecosystem in the sea. It is also known as the ‘Oasis’ of the sea or ‘The Rainsforest’ of the sea. The reef ecosystem supports abundance of life and many species thrives in this ecosystem. Although its coverage is small compare to the ocean floor, but its function is overwhelming than its size! The richness and importance of this reef ecosystem has been well documented and shown in various media formats. The most famous and known to all is the BBC documentary ‘The Blue Planet’, the Walt-Disney animation ‘Finding Nemo’ and also by Jacques Cousteau expedition team. Even the famous coral reef ecosystem in Malaysia, Sipadan Island was discovered by Jacques Cousteau himself! Malaysia is in the Coral Hotspot of the world and the number of coral species is more than 300 species. According to Jen Veron, the author of ‘Corals in Space & Time’, the north of Sabah is part of the ‘Coral Triangle’, which housed most of the species in the world and new species is still being discover. Malaysia have 42 islands which has being gazzetted as Marine Parks, and have been placed under governance of newly established Marine Park Department of Malayisa This Department is responsible in safeguarding, and manage the coral reefs from various activities which can degrade the reef ecosystem in Malaysia. Nevertheless, there are still many islands flourished with beautiful coral reefs and submerged coral reef ecosystem which is not a marine park, such as Pulau Jarak, Pulau Perak and the submerge reefs in Malaysian waters of the South China Sea. In 2004, the Ministry of Science, Technology & Inovation (MOSTI) has funded an expedition to explore the wonders of the coral reefs in Malaysia’s submerged reef in the South China Sea. The National University of Malaysia (UKM) in particular researchers from the Ocean Science Programme and Marine Ecosystem Research Centre (EKOMAR) were given the privilege to contribute to the expedition, of which all of them were overwhelmed by the pristine and richness of the coral reef ecosystem that proudly is in Malaysian waters.

Coral reefs are a source of food and livelihood for at least 100 million people worldwide, support major industries, play a key role in stabilizing coastlines, and their high species and genetic diversity rivals that of tropical rainforest. This biodiversity is now just beginning to be exploited in search for bioactive compounds that could benefit humankind. Prostaglandins, which is a natural product chemicals, contain in gorgonian has a wide range of clinical applications in assisting medical emergencies. Coral reef ascidians or also known as sea squirt, is also known to contain Didemnin B, which is use widely to battle against leukemia, varieties of human tumors, viruses and carcinomas. There are more natural chemical products constantly being discovered from coral reefs, and many more cures to be discovered, which makes them utterly important and should be protected. Coral reefs are also home to many species of reef fishes. It is known that the standing stocks of the coral reef fishes are about 30-40 times greater than standing stocks on demersal fishing grounds in Southeast Asia, the Mediterranean, or other temperate regions.

Coral reef ecosystem is consisting of reef building organisms, which are the corals, and many other co-exist organisms that form a complex ecosystem. Corals are the functional group that has contributed significantly to coral reef ecosystems for at least 200 million years ago. They have been known in building the primary structure of entire reefs and islands. Corals is classified as ‘Animal’, which means they are neither rocks nor plants, as it is often perceived by many. They are colonies of coral polyps with naturally embedded with symbiotic algae living in its mesoglea soft tissue providing nutrients by conducting photosynthesis. This algae is known as zooxanthellae, a kind of domain Dinoflagelate (Symbiodinium microadriaticum). The others associated communities of the corals, such as the giant clams, sea cucumber, sponges, sea anemones also plays important role in the ecology of this ecosystems. The molluscs or shells and sponges are the natural filters for the reefs. Their feeding mechanisms, which is filter feeding, helps in maintaining the turbidity of the crystal clear waters of the coral reefs. Sponges also acts like cement, where it bonds the coral structure together which strengthen the coral reef framework. Algae in the reefs helps in recycling nutrients and starfish (Fromia spp) recycle the organic materials found on the sea bed. Sea cucumber acts like a vacuum cleaner, where it feeds on the organic materials on the seafloor. The sea urchin is the gardener of the reefs where it feeds on algae and helps in maintaining the algae from overpopulating the reefs. There are also other non-conspicuous organisms, or also known as cryptic organisms such as the trapeziid crab and the cleaner shrimp which is also plays an important role in the reef ecosystem. The cleaner shrimp, Periclemenes spp., can be found living in between corals, such as Pocillopora and sea anemone such as the magnificient sea anemone, Heteractis magnifica. They helps preen the ‘house’ which they live within and receive foods and protection from it, this relationship is also known as symbiotic relationship. Besides preening, they are also the first defence for corals, such as Pocillopora spp., has against Crown-of-torns (Acanthaster planci). The complexity of the coral reefs ecosystem makes it the ideal place for many marine organisms to thrive and survive. It is essential for everybody, all woks of life, all level of education, to understand the importance of coral reefs, in order for all of us to protect it."

Coral Bleaching

This is one of the article I wrote for a coffeetable book published by EKOMAR.

"Coral bleaching is now the most significant and widespread threat to coral reefs in the world and it is predicted that with climate change, the frequency and intensity of bleaching will increase. Coral bleaching is a process in which corals are subjected to constant stress and disruption of their symbiotic association, resulting in the loss of their single-celled symbiotic algae, known as zooxanthellae. The constant stress can be either drastic temperature changes or increased temperature, long exposure to high ultraviolet radiation or even pollution. Zooxanthellae live within the tissues of the corals and supply them with essential nutrients, while in return, the corals provide a suitable habitat for the zooxanthellae to thrive. When corals lose their zooxanthellae, their white skeleton can be clearly seen through the transparent tissues of the polyps, thus making the corals look bleached. However, not all bleached corals are white, there are cases where the corals produce a vivid fluorescent hue, resembling a fluorescent neon light underwater. To some, it is a beautiful sight to behold, but alas for the corals, it is a sign of much stress and eventual death.

Besides coral bleaching due to expulsion of its zooxanthellae, the grazing activities of the ‘Crown-of-torns’ or Acanthasther planci and the Drupella spp. shell also cause the corals to look bleached. The Crown-of-torns is related to the sea urchin, starfish and cushionstar, classified under the Phylum Echinodermata, whereas the Drupella spp. shell belongs to the phylum Mollusca. These corallivores that feed mainly on corals are known to cause devastation in a reef area if their populations explode unchecked. Numerous patches of bleached dead corals indicate their feeding voracious activities, whereby the corals died their calcium carbonate skeletons will be overgrown by algae. Newly grazed corals may also be easily mistaken as coral bleaching, but upon closer inspection, the difference between bleached and grazed corals can be discerned easily. Bleached corals are not necessarily dead, since despite losing their symbiotic algae they are still very much alive and most of the corals will regain their zooxanthellae once they are able to recover and cope with the stress. Bleached corals look extremely clean and somewhat glowing because they are able to actively remove sediment or other particulate matters that descend upon them. In contrast, grazed corals will be colonised by algae with the presence of a thin film or haze of green, brown or yellow.

In Malaysia, mass coral bleaching was first reported in 1998. The coral bleaching issue in Malaysia was still very new then, was little understood and drew scant attention. Subsequent reports on coral bleaching were those of Pulau Payar in 2001 and Pulau Langkawi in 2004, which were published in reefbase of Worldfish Centre. The most recent bleaching occurs in Tioman Island (2008), which has caught the eyes of many scientists and marine park managers in Malaysia. In this situation, the first course of action is to identify the sources of the stress, the extent of the coral area bleached and the best course of action to be taken. There are protocols and methods which have been developed to guide scientists and park managers in facing this epidemic, and most of these protocols are offered free online!"

Sea Anemone of Malaysia's Coral Reef

This is a short write-up of sea anemone for a poster I made for EKOMAR. Hope all of u enjoy reading it :).

"Sea anemone is a close relative to corals. It is members of the Class Anthozoa within the Phylum Cnidaria. It is one of the known organisms that have very obvious symbiotic activity. It feeds on planktonic plants and organisms, but it gets its important dietary supplement from its symbiotic algaes called zooxanthellae. Besides symbiotic algaes, sea anemone mainly from the genera Heteractis and Stichodactyla; also play hosts to certain damselfish, mainly Amphiprion spp., or commonly known as clown-fish or anemone fish. The fish depends on the sea anemone for habitat purposes and the fish helps preen the tentacles, keeping anemones in a healthy condition. Anemone fish immunes itself from the stinging cells of anemone by a combination of unusual swimming behaviour and special chemicals in the coat of its body. There are 1000 species of sea anemones in the world and only ten species are known to be host to anemone fishes. Out of the ten known host anemone, six of them can be found here in Malaysian waters. It is important to understand the distribution of these organisms as they also have biological and chemical influences to the surrounding ecosystem. Sea anemones have been reported as a limiting factor to the development of reef building corals.
By understand this mechanism, a better management of a reef ecosystem can be proposed. Assessment of the reef health research has been ongoing and many potential organisms, which act as an indicator for physical parameters influence, have been introduced, such as Amphipods, which are sensitive to changes in salinity. Sea anemone can also be used as a potential animal as an indicator organism for UV radiation in the marine environment. This is important in giving an in-situ overview of the UV radiation to the marine environment, as marine organism larvae are susceptible to UV radiation. Sea anemones produce many biologically active polypeptides and proteins, which are a very important tool in neurophysiological and pharmacological researches, as blockers and modulators of K+ and Na+ channels. A green fluorescent protein (GFP) is extracted from Heteractis magnifica, which is used in vivo marker in cellular, development and molecular biology. Sea anemone is a well known organism, which has an obligatory relationship with anemone fishes and damsel fishes. The relationship of anemone fishes with sea anemone is mutualistic. The anemone fishes avoid predation by sheltering within the anemones and individuals of some species vigorously protect the anemone from predators, such as fishes of the families Chaetodontidae and Tetraodontidae, gastropods, asteroids, and sea turtles. The number of Anemone fish enthusiasts has increased ever since the ‘Finding Nemo’ animation movie was shown a few years back. Aquarium shops have seen an increase in anemone fish displays, which means an increase in demand by marine aquarium enthusiasts for anemone fishes. This indirectly can cause a decrease of their abundance in the wild, since poaching of anemone fishes is likely to happen to facilitate the increased demand for them. Sea anemones also have other associate organisms, such as the anemone shrimp from the genus Periclimenes, juvenile butterfly fish of the Chaetodon kleinii, and wrasses of the genus Thalassoma. There is a high number of associate organisms that live with and within the sea anemone. The decrease of sea anemone abundance can link to the decrease of many other organisms associating with them. Although many researches have been conducted on the sea anemone internationally, their distribution in Malaysian waters is still scarcely known."