To share his newfound happiness, Chen once posted a photo of himself holding a branch of coral on his micro blog. He was surprised when a friend in Australia commented that what he did was detrimental to the environment and that if he were in Australia, he would have been punished by law.

"I was shocked. I didn't want to be a bad guy. After that incident, I became more aware of the environment."

Chen began noticing that fishermen from nearby islands were threatening Zhaoshu Island's surroundings.

The fishermen usually come to the island shortly after Spring Festival in February, and leave before the typhoon season, which begins in August.

"When they are on Zhaoshu Island, they fell trees to make firewood, and as time passes, the trees reduce in number and this causes a drop in the bird population.

"The fishermen also bring with them cats to catch mice on the island. The number of cats have multiplied, and when they can't find enough mice, the hungry wildcats start attacking the birds," Chen explains.

"I was no longer living in paradise. Instead, I began seeing environmental problems and felt a strong urge to solve them," Chen adds.

He says one feels more connected to nature on an island because of proximity and therefore, the desire to protect it. But in cities, where one is surrounded by the concrete jungle, the connection with nature is remote.

Chen started talking to fishermen trying to convince them to fish less, or at least fish farther from the shore.

He achieved some success with some fishermen adopting trolling. But there were many who won't listen.

Realizing that he could not achieve much alone, he left the island and moved to Haikou, Hainan's provincial capital in August 2011.

In the meantime, he takes every chance to lobby with the relevant authorities. The establishment of Sansha city, Chen says, has provided a possible avenue.

He says he has started calling on the new city authorities, to show them his research conclusions, and persuade them to take effective measures to protect the sea and islands from being overly exploited.

Li Ming, an official of the Education, Culture and Public Health Bureau of the newly established Sansha City government, has come to know Chen because of his appeal for the protection of the islands.

"Environmental protection will be a focus of our policy for the islands. In fact, we have already started making plans," Li says.

Contact the writer at liuzhihua@chinadaily.com.cn.