In 1994, Xiamen issued its first rules on the use of sea areas, regulations for oceanic environmental protection and regulations on conservation of the Chinese white dolphins.

Further, in 1997, the provincial Chinese white dolphin reserve of 5,500 hectares was set up in Xiamen to try to lure back the rare mammals.

"It's no easy task," said Zhou. "Dolphins feed on various kinds of fishes and shrimps and eat as much as seven kilograms of food at a time. They also require a high-quality water environment."

Meanwhile, "the environments suitable for dolphins are suitable for human beings as well," said Zhou.

Efforts have been made to improve and restore the marine ecosystem around Xiamen since the mid-1990s, with another 30-odd related laws and regulations issued following the 1994 rules and related public awareness campaigns built through media publicity.

Zhou divided the process of comprehensive management of marine ecology of Xiamen into three phases.

Firstly, pollution control. Waste materials were prevented from being directly discharged into the sea as more refuse disposal and sewage treatment plants were built.

Secondly, during the first decade of the 21st century, ecological reconstruction was put on top of the city's development agenda. Sea areas were allocated to more ecological and environment-friendly industries.

"Now we're in the third stage -- to restore the marine ecosystem of Xiamen," said Zhou, highlighting such projects as releasing fish fry into the sea, dredging silt from nearby sea areas and blasting part of the Gaoji Causeway to ease the water flow.

These efforts, said Professor Yu Dongsheng with the Xiamen-based Third Institute of the National Oceanography Bureau, had good results in conserving endangered animal species and expanding the living space of Chinese white dolphins.

"According to the data collected through marine monitoring stations, the number of dolphins around Xiamen has been increasing steadily since 2005," said Chen, adding that the population increase pointed to improvements in the quality of the marine ecosystem.

"When I was jogging along the beach one morning last October," Chen Wang, a citizen of Xiamen, recalled, "I saw three dolphins. And a month later, when I was on a boat, I saw five. Oh, they' re fantastic!"

More and more tourists will be able to share Chen Wang's excitement.

"We're going to set up some observation spots for tourists to watch dolphins more conveniently," said Zhou, hoping the move will also help people further understand the sea and act to protect it.

"Xiamen is a garden city in the sea. Isn't it wonderful to have dolphins around it?"