Zhan Xiaofeng was born in Zhanjiang City, south China's Guangdong Province. Even though she was raised near the sea, she didn't like it. "Because the sea was murky and dirty when I was young," she said.

Zhan dove for the first time in 2014 after falling unexpectedly for the charm of the sea: "I saw the magnificent coral reefs in Greece and Australia." Every time she dives now, she immerses herself in the miraculous beauty of nature.

In 2016, she saw that a charity organization was recruiting volunteers to clean up marine debris at Dapeng Peninsula in Shenzhen City. She decided to join them.

The situation was far more severe than she had imagined. "What I saw under the sea in Shenzhen was catastrophic." The visibility was less than a meter, and fishing nets and rubbish was everywhere. Coral and fish could hardly be found on the desert-like seabed, which was covered only with rocks and algae.

"Corals are animals. They cover only 0.2 percent of the oceans, but the coral reefs nourish 33% of marine life on the planet. They also protect us from typhoons and huge waves, which is similar to the tropical rainforest," says Zhan. "Anyone who dives would feel the responsibility of protecting this beautiful yet fragile ecosystem."

Human activities such as anchoring, trawling and scuba diving can harm the coral reefs. Shocked by what she saw, Zhan decided to begin professionally protecting the coral reefs and the sea. She became a certificated diving coach and is devoted to the cleaning missions.

Every month from May to October, and when the weather is suitable for diving, Zhan and other volunteers organize rubbish cleaning activities. One time, they dredged more than 400kg of garbage.

Since 2012, the organization has been growing coral artificially in more than 20 ponds. However, the cost was too much, so in recent years, they have turned to focus on the preservation of existing coral reefs.

The divers collect fragments of coral during the cleaning and raise them in nurseries, before replanting them where they were found.

Besides for this, the volunteers hold lectures and educational events for young people. "As sea lovers, it's our duty to raise public awareness of the importance of coral reefs," says Zhan.

Now, more than 3,000 volunteers have signed up like Zhan did to protect the coral reefs. Among them are over 1,000 divers and 200 frequent participants.

"Through our efforts, I wish the remaining coral reefs in the region can be well protected, restored and thrive again."