Vietnamese corals are comparable to world corals

With the number of 400 different species of corals belonging to 80 species, 17 different families, the marine coral fauna of Vietnam is comparable to the most diverse coral regions in the world.

Summary of coral information:

1. Coral is very fragile but they are also very sharp
2. Coral is considered a good food for whales and many other marine animals
3. The coral belongs to the same family as the jellyfish
4. Most corals are found in warm and subtropical warm waters, but there are also many soft corals living in colder regions of the world, even in the Antarctic.
5. In recent decades, more than 35 million hectares of coral reefs have been destroyed.
6. Coral reefs are currently one of the most threatened ecosystems on our planet. If the level of destruction continues today, 70% of the world's coral reefs will be destroyed in our time.

How is the coral shaped?

Corals look like plants, and in the past naturalists have described coral reefs as gardens. In some parts of Vietnam, people call corals a stone flower. But if you look closely, you'll see that corals are made up of very small creatures called coral polyps.

Each coral polyp is like a seaweed with a bag-shaped body and only has an open mouth for food and waste. Around this mouth are tentacles with itchy cells.

A coral group is not a group of single polyps that live together for the common good, but the result of the maturation and sprouting of a base polyp.

Polyps in a coral cluster share a common fluid and nervous system. All are genetically similar and polyps are linked by a thin layer of tissue.

Where does the coral live?

Coral reefs that form on the surface wear solidly in warm, shallow, and clear waters.

The sea water there must be:

1. temperature 22–29o (average annual temperature)
2. clear water, low turbidity
3. Less nutrients
4. stable salinity

- Coral reefs grow around continental slopes or continental banks. They are known as fringing reefs.

- Atolls formed from coral reefs around volcanic islands are now turned off.

- Background coral reefs are often found on continental shelves.

- Ribbon-shaped coral reefs (also called barrier reefs) are elongated shaped beds growing along the edge of the continental shelf.

What do corals eat?

Coral polyps hold food. Each polyp has a mouth surrounded by tentacles with tiny cells like the cramping of tiny creatures swimming in the water.

The tentacles push the food of polyps through their mouths and also inject predators!

The mouth connects to the cylindrical intestinal cavity containing digestive tissues.

In some months of the year, digestive tissues also contain a growing genitalia. Some polyps have both male genitals (sperm cells) and females (egg tubes).

How does coral reproduce?

Corals reproduce sexually or in many other ways, such as splitting themselves into two organisms or releasing growing polyps elsewhere. Corals have very interesting reproductive ways and many species use not just one method.

Branching: fragments of branched or discus corals can separate and attach themselves to the surface of the coral reef where they continue to grow. Branched corals in rough seas or where many creatures go there to eat or rub through them.

Breeding dichotomy or 'sprouting': coral fungi can self-divide into two or more organisms.

The escape of the polyp: when the coral bumps are stiff, it can release the polyps so that they live elsewhere.

Polyp shadows: At the day, coral releases small, shapeless tissue into the surface of coral reefs so that they grow near their parents and form new coral clusters.

Asexual reproduction: some flower corals and murky corals have very young individuals that grow on their tissues. They are produced only from one egg, not from a combination of sperm and eggs. Once released, small polyps settle down and grow near the mother.

Sexual reproduction: there are two types of sexual reproduction:

1. Reproduction of larvae within polyps: this reproduction is like asexual reproduction, except that small polyps are born from a combination of sperm and eggs.
2. Mass reproduction: at least 100 types of reef-building corals on the Great Barrier Reef release eggs and wrap sperm into the water during the first few nights of the summer. Growing eggs and larvae swim along the flow a few days later. Mass reproduction occurs between 3 and 6 nights after the full moon and when the sea warms after winter. After floating on the surface of the sea, egg and sperm wrappings break out so that egg cells and sperm cells meet and they can fertilize. Of the millions of eggs and sperm produced, only a few eggs can fertilize, settle and survive until adulthood. The rest are wonderful food for fishes!

Coral, with the colors of the rainbow and the shape of the size is very diverse, is a unique and essential part of the life of the Vietnamese sea.

Coral reefs are one of the oldest, most biologically diverse and rich ecosystems on earth. They also support symbiotic (mutually beneficial) relationships among organisms in the natural world. Although only by very small creatures, corals create beautiful ridge along the coast of Vietnam and are home to a variety of marine species.

Each coral creature is part of this reef ecosystem and is also part of the process of forming a new reef. Some corals develop very slowly, less than 1cm per year, while others grow very fast, each year up to 15cm. However, the size of the coral reef does not indicate its sustainability.

Coral is very sensitive to disturbance, and human carelessness can seriously affect the health of coral reefs in general. The condition of a coral reef is closely related to the surrounding mangrove and seagrass ecosystems. Mangroves and seaweeds filter nutrients from land sources and are a shelter and nurturing cradle of many coral reefs.

Coral is currently under threat, corals are damaged in 93 countries and corals may disappear in the next 20 years. The threat to coral reefs is no longer a matter of every country but a concern around the world. With about 20% of Earth's coral reefs irreversibly damaged, 24% are threatened and 26% face long-term threats, the international community must do more to protect them. If we let the coral reefs die with the rise of sea level, thousands of islands in the world will disappear, leading to them as communities and cultures.

Coral reefs are found in more than 100 countries and cover about 285,400 km2 worldwide. They are the most diverse ecosystem of the ocean, with the only rival being the only tropical land-buying forest. 25% of all marine animals, including thousands of wonderful fish species, mollusks, sea urchins, etc., live in it. Due to over-fishing, the amount of fish in coral reefs has been significantly reduced in some parts of the world. This has made the coral ecosystem unbalanced, enabling other organisms such as marine algae to grow. As a result, marine algae, once controlled by fish, became overwhelmed on the reefs in many areas. In addition, many fishermen use coral reefs and sea lagoons on the sea floor to look for fish of high economic value.

As human population increases and socio-economic activities develop, the amount of wastewater discharged into the sea also increases. Wastewater can carry a large amount of sediment from cleared areas, nutrients from agricultural areas, pollutants such as petroleum products and pesticides. All of these wastes increase the turbidity of the seawater, reduce the amount of light reaching the coral, thus causing coral bleaching.

Coral is also a favorite ornament. Often when vacationing in tropical waters with beautiful coral reefs, some people want to buy some coral souvenirs brought home. To satisfy the needs of tourists, local people have exploited corals with commercial scale and choose corals so that they can earn the most money. This situation is also happening in Vietnam.

Oil spills, oil leaks into the sea, ship anchors as well as aground sea-going ships also destroy a large part of coral reefs. Researchers have found that paint coated on the bottom of many ships also contributes to the formation of Tributyl tin toxins, along with other chemicals that are harmful to corals. Surveys show that pollution, over-fishing, rising temperatures, coastal development projects and diseases are major threats to coral reefs.

About 70% of the world's coral reefs are being destroyed or endangered by human activity. However, some reefs are expressing their ability to surprisingly recover from global warming. Countries around the world should do more to reduce pollution, limit fishing and cut greenhouse gas emissions (such as CO2) to protect corals. To save coral reefs, governments need to quickly reduce CO2 emissions. The temperature on Earth has risen 0.6oC since the late 1800s to now.

In Vietnam, from the end of 2003 until now, fishermen in coastal areas are still free to exploit black coral, seriously affecting the marine ecosystem. From the end of 2003 until now, every month Chinese merchants have come to these areas to buy hundreds of tons of black coral as raw materials for craftwork. The average purchase price is from 150,000 to 200,000 VND / kg, while this price is up to 2 million VND / kg when brought to China.

Application of corals in bone healing:

- In eye-scanned cases: Since 1998, the product has started to be put into use at HCMC Eye Hospital. So far, coral balls have been used the most with over 100 ca. For the unfortunate patients who suffer from traffic accidents, injuries or illnesses, they must scoop out their eyes . immediately after scooping eyes, the doctor grafted a coral ball into the sclera to shape the eye sockets, hold The eyeball muscles are in place, not atrophy. After being healed, the doctor put the artificial eye in. The patient can glimpse.

- In teeth - jaw - face: when pulling teeth, the doctor can transplant corals to fill the jaw line, resist the atrophy of the jaw so that when the dentures are placed, it will be more convenient. In cases where the tip of the tooth is deep, inflamed, creating cavities called the apical follicles, the treatment of the inflamed bone must be removed and a gap will be left and the bone must be grafted. Previously, it was very expensive to use French HTR materials. Now using VN coral only after about three months, the coral is replaced by bone, assimilated almost normal.

In 2003, began using corals to shape parts of bone defects for patients with jaw bone, cheekbones, eye sore bones . These patients had to accept the dented, deformed face due to missing bones or having to use cement, titanium is very expensive and after transplantation it is not self-absorbed.

While inserting coral material in addition to the original shaping, will be replaced gradually by the body's own tissue. The therapist creates pre-shaped frames on patients with plastic or plaster, and based on that, they will create coral pieces using manual techniques. Faculty of maxillofacial surgery Institute of Maxillofacial teeth has been matched for six such cases.

- In pathological conditions that cause marrow compression due to spinal stenosis (due to osteoclast or discus, pinched into the pulp): the treatment is to expand the spinal canal, use coral as a grafting material to widen the tube living. Ho Chi Minh City Orthopedic Trauma Hospital has applied for 10 cases, Neurosurgery department of Cho Ray Hospital performed for over 30 cases.

Le Thi Thu Nga
(3rd year student of science, University of Natural Sciences)