Scientists learn to dive in order to grow corals. How difficult is it to rebuild a submarine "Saihanba"?

When it comes to coral, the picture that comes to mind should be:

But in recent years, many of them are no longer beautiful and become white. ...

With the deterioration of the earth's marine environment, coral bleaching is becoming more and more serious. If coral bleaching is serious, it will eventually die because of insufficient nutrient supply, leading to the degradation or even disappearance of coral reefs, and the ecology will be greatly affected.

The original appearance of coral world.

Coral is a kind of lower coelenterate, and the part that looks like a branch is actually a "tentacle"-coral, old coral dies, new coral is born on calcium carbonate deposits, passed down from generation to generation, and finally forms a huge coral reef or coral island.

Why do corals have colors? Because they live with algae. For example, reef-building corals often have a tiny unicellular protozoa with yellow-brown pigment, commonly known as "zooxanthellae", which provides photosynthetic products for host cells through photosynthesis, while the host provides inorganic nutrients for zooxanthellae.

Coral provides a living environment for nearly 30% of marine species, which makes coral reefs one of the most diverse ecosystems on earth, and 500 million people in the world depend directly on coral reef ecosystems for their livelihood.

When the marine environment changes, such as sea water warming and environmental deterioration, algae will be forced to leave the host coral, and finally, people will see coral bleaching, which is their carbonated bones.

When the global corals encounter such bad luck, our corals are not spared.

There is a coral researcher. She and her research team traveled all over the coral reefs in China in 20 years. She is Huang Hui, a scientist who grows corals in the South China Sea. From Fujian to Xisha Nansha, they witnessed the changes of coral reefs in the past ten years.

What's the current situation of corals in China?

"The coastal corals lost 80%, and the coverage rate of reef-building corals on outlying islands dropped from 50% and 60% to the present 10%- 15%, just like the forest coverage rate." Huang Hui said.

Become a scientist who can dive.

Coral grows in the sea, which means that if you want to study it, you must learn to dive.

Huang Hui said: "When you come to our team, whether you are a student or working in a team, the first thing to do is to learn diving and get a diving certificate. We all have to dive and work in the front line to get the most front-line data. "

Huang Hui and his team members will take a fishing boat to the launch site. When renting fishing boats in the early days, fishermen refused to let women board the boat because of feudal ideas, even ignored Huang Hui, preferring to communicate with her deputy. After a long time, the fishermen's attitude changed greatly when they saw that Huang Hui had repeatedly overcome the inconvenience and insisted on diving in the sea.

"seasickness, life is worse than death." Huang Hui not only suffers from seasickness, but also wears diving equipment weighing more than 30 kilograms to make her stand up.

In the process of diving, the sea is still surging. "You will spit in the water, spit it out, and then bite your breath." Huang Hui said with a smile, "I often tell students that diving is fun if they love this career, otherwise it will be very hard. So, still love it. "

Huang Hui still remembers the first time he went into the South China Sea in 2002 and saw many corals, which were full of fish, lobsters, sea cucumbers and sea urchins. "That scene was really shocking and exciting." Today, this scene is slowly disappearing.

Scientists study at the bottom of the sea

Looking at the continuous degradation of coral reefs, scientists ask, why not plant cuttings on the seabed like afforestation to expand the living space of coral reefs on a large scale?

In order to restore and plant corals, Huang Hui began to study reproductive biology, how corals lay eggs and how developing larvae attach themselves.

She and the team tried a variety of recovery methods: collecting the floating wave cubs ashore for sexual reproduction and cultivation, and then returning them to the bottom of the sea; Nail a shelf on the seabed, and tie the coral to the shelf with a rope to form a coral tree; Pull up the grid and plant corals on the floating bed.

Planting corals on the seabed is very similar to afforestation on land, and both need seedlings and nurseries. For example, making a tree nursery is a technology learned from foreign experts. Huang Hui once said in a speech: "We always do this when we start scientific research. We are behind others and must admit backwardness, but we have been catching up. "

Coral can reproduce asexually or sexually. In order to study the reproduction of coral, coral eggs were collected from the potential seabed at 90 pm in the coral breeding season. "Because its survival rate in the sea is very low. We take it to the shore, cultivate a lot of larvae, and then release it. This is also a means of repair. " Huang Hui said.

Planting coral forest

"Our goal is to restore the entire coral reef ecosystem, so we should not only plant corals, but also cultivate other creatures in the entire ecosystem, such as seaweed, seaweed and shellfish, so that they can live in harmony." Huang Hui said.

Compared with land afforestation, it is more difficult to grow corals on the seabed. "We have encountered many difficulties, such as how to prevent artificial and typhoon damage to planted corals. The corals that have just been transplanted from the nursery to the seabed are unstable and the typhoon is a great threat. " Huang Hui said.

Yang Jianhui, a research assistant, said: "Working in the water at night may lead to poisonous creatures, which is very dangerous. If you encounter it, you should get on the boat immediately and take emergency measures. "

In addition, the workload of underwater operation is large and the cost is high. On the basis of the survival of coral cultivation, scientists should also find ways to reduce the cost of manpower and material resources.

Today, they have spent more than ten years planting100000 square meters of coral in the South China Sea in China.

Coral reefs grow slowly. The fastest antlers can grow about ten centimeters a year, and some varieties are less than one centimeter a year. It may take decades or even hundreds of years to plant a large area of undersea forest.

This is a scientific research and hard work, and for corals, it is a slow "recovery" future. Scientists hope to promote the concept of "marine pasture" and restore marine ecology by restoring corals.