Along the Luhuitou Peninsula in Sanya City, Hainan Island, China, under the waters of East and West Meizhou Bay and Yalong Bay, there are large areas of beautiful corals, of which more than 80 kinds of reef-making corals. When you dive to the bottom of the sea and look at these colorful corals, do you think: Is the coral that looks like a forked branch and flower a plant? What is the causal relationship between it and the coral reef?
<h1>Tropical rainforest in the ocean</h1>
Coral is actually people's habitual name for coral insects, it is not a plant, but a tiny coelenterate called a coral, which has high economic value and ecological value. Polyps are mainly groups, they are gypsies in the ocean, they like to swim around, the sea is home. The shape of a single polyp resembles a small fleshy pocket, topped by the coral's mouth, surrounded by fuzzy tentacles. Seemingly docile corals are actually carnivores, they catch food from the sea through their furry tentacles, and the polyps digest the food and secrete lime, forming bones and gray matter shells. When the polyps die, their skeletal remains accumulate, and newborn offspring multiply and grow on these remains, and over time, they form a kaleidoscopic coral form on the seabed.
Rocks are the best adhesions of corals, and once they touch rocks or reefs along the coast, they take root and grow; in addition to rocks, corals can attach to fine sand and muddy substrates on the seafloor. The generational continuation and accumulation of coral life has led to coral reef coasts, and their morphology is unique among all tropical coasts. Moreover, coral reef biomes are rich in rare organisms and are important marine areas for the conservation of marine biodiversity.
Sanya coastal natural environment is good, very suitable for the growth and reproduction of corals, coral species and quantity in China's coastal waters occupy a leading position. Over the long geological period, a variety of corals have multiplied here, forming large coral reefs. Coral reefs provide spatial gaps of different sizes, allowing a variety of fish, shrimp, shellfish, algae and other marine life to inhabit and thrive, forming a beautiful underwater landscape. In the underwater world, coral reefs enjoy the reputation of "tropical rainforest in the ocean" and "great wall of the sea", and are considered to be one of the oldest, most colorful and most precious ecosystems on earth.
<h1>Small corals make big reefs</h1>
Corals have a wide range, but are mainly native to shallow tropical seas, and are more common in temperate and boreal seas (especially shallow coastal areas), and even in the ultra-abyssal zone, there are representatives of polyps (such as sea anemones). China's tropical seas are vast, coral reefs are widely distributed, and there are many types of reef-building corals. Corals can be seen along the coasts of the South China Sea Islands, Hainan Island, Taiwan Island and Penghu Archipelago, as well as along the coasts of Guangdong and Guangxi. Among them, the atolls are mainly distributed in the South China Sea zhudao, and the shore reefs are mainly distributed along Hainan Island, Taiwan Island and Penghu Islands, as well as along the coasts of Guangdong and Guangxi. There are far more reef-building coral species in Taiwan than in other regions, which is related to the region's long-term exposure to the warm Kuroshio Current in the Pacific.
Coral reefs cover less than 0.5% of the world's oceans. 25%, but more than 1/4 of known marine fish live on coral reefs and are interdependent with coral reefs. Most reef-building coral tissues themselves have no pigments, and most of their beautiful colors come from the symbiotic algae in the body; under normal water temperature conditions, zooxanthellae always coexist with polyps, staining coral reefs with a golden, red or yellow glow. The corals that we usually see as white as jade are actually coral bones that have been washed by artificial soaking after the death of the coral insects.
These micro-symbiotic algae provide energy to polyps and form material cycles between them, such as coral algae and cactus algae, which are the constituents of marine coral reefs. Every summer, when the water temperature rises, corals in many places "bleach" . Because if the water temperature is too high or too low, the salinity in the water plummets due to heavy rain, the sea water is too turbid, and other harsh environments, the symbiotic algae will leave the host - the coral, the coral, resulting in the entire coral tissue losing color and becoming transparent, directly exposing the coral white calcareous bones. However, in the short term, the "albino" corals have not died, and if the environment can quickly return to normal, the symbiotic algae may grow rapidly again, so that the corals can return to their original beautiful colors.
Coral reefs have many functions, which not only have a protective effect on the coast, but also store oil and gas resources and have certain medical value. In addition, the marine zoo and nature reserve established in the coral reef area are not only people's tourist resorts, but also scientific research bases.
<h1>A substitute for human bones</h1>
Coral reefs deep in the ocean are one of the largest structures that living things can create. Some people call coral reefs an oasis in the "ocean desert", and countless biological populations regard coral reefs as their palaces and inhabit them for many years.
Coral reefs are hard because corals absorb calcium and carbon dioxide from seawater during their growth, secrete limestone, turn it into their own shell, and bond these limestones together through generations of metabolism. In this process, due to the absorption of a large amount of carbon dioxide, the greenhouse effect is also reduced to a certain extent. Coral reefs not only balance the natural environment, but also help people relieve their pain.
As early as the 1970s, Dr. Patat, a French physicist, discovered that corals have many similarities with bones. Thus, for the first time in France, corals were implanted in place of bones. Dr Caylaimin said: "We didn't expect that the coral reefs placed in the human body would be absorbed very quickly and converted into bones, which is simply a huge discovery. Because in the past, synthetic materials were used as a substitute for bones, which was simply a torture for people. Now it's different, the reef is perfectly able to fuse with the broken bones, just like the newly grown bones. ”
While ensuring that coral reefs can be regenerated, the collection of medical corals does not pose a threat to coral populations. Every year, more than 2 tons of coral reefs can be collected from the Indian Ocean and the Pacific Ocean, and marine biologists can select the most suitable parts, followed by chemical analysis, and after sterilization, disinfection, milling, and fencing, the coral reefs are cut to the size required by the patient. Some surgeons even make corals into glue that connects bones. For example, one patient suffered a comminuted fracture of the external tibia in an accident. The doctor fixes the fracture site and then inserts the polished coral into the fracture. After 1 year and 3 months, the fracture site of the patient was completely healed, and the coral filling was completely transformed into the skeleton of the human body. So far, 100,000 patients have received transplants from coral reefs, and none of them have seen rejection so far. Today, corals have replaced synthetic materials and are increasingly used in plastic surgery and nerve therapy.
<h1>Guide the young fish home</h1>
At dusk, the reef's dreamy tranquility comes to an abrupt end. The sea began to be filled with creaking and clanging sounds, and the noise of fish hunting and dozing shrimp could be heard on the shore thousands of meters away. A new study suggests that at night, this noise in coral reefs may have an important function: to guide young fish home.
After hatching, the small fish of the reef fish can drift far away from the reef. But by the time they reach maturity, they must go home or find another reef to find suitable food and mate. Previous studies have shown that fish in puberty have excellent hearing. Stephen Simpson, a fish ecologist at the University of Edinburgh in the United Kingdom, therefore speculates that young fish may find their way back to the reef with the guidance of sound.
To test the idea, Simpson and colleagues placed 24 piles of coral rubble on flat underwater sand near Australia's Great Barrier Reef to form artificial reefs. Over the course of 6 nights, the researchers selected half of the reefs, played the clamor of reef fish, while the other half did not, and then collected the number of fish moving around each reef the next morning. Scientists report in the latest issue of the American journal Science that there are far more fish near coral reefs that play fish sounds.
Peter Doherty, a fish ecologist at the Australian Institute of Marine Sciences, commented: "These fish are definitely using sound cues in the final process of approaching the reef. He also noted that fish may also exploit smells or other cues. Understanding how young fish drift and how they return to coral reefs can help biologists plan marine protected areas that protect fish at critical stages in their life cycle.