Hainan is best known as a tropical tourist resort. Thirty years ago, it became a special economic zone and since then, China's southernmost province has also become famous for its fresh water fish farming. And its biggest fish export, in volume and value, is tilapia, at one time supplying half of the global demand, although that has fallen now to 30 percent. Our reporter Wei Lynn Tang visited a fish farm in Wenchang county to find out what lies ahead for this industry.

There is a saying: Give a man a fish, and you feed him for a day. Teach a man to fish, and you feed him for a lifetime. This may look like a simple, routine task, but to do it well everyday, over the span of 22 years, Fan Biyan can now proudly say that she has mastered the art of fish farming. From feeding her tilapia, monitoring their conditions, and attending to them when they fall ill.

FAN BIYAN TILAPIA FISH FARMER "Tilapia has changed my life. When I first came here, I did not have any money. But I now have my own home, and have even sent my son to the United States to study, to be a pilot. This industry has given me an entrepreneurship platform."

WEI LYNN TANG WENCHANG, HAINAN PROVINCE "China is the world's largest tilapia producer, at some 1.9 million tons in 2016. And right here in Wenchang, China's southern-most-province of Hainan, is one of the country's most major fish production hubs."

In 2015, however, the tilapia industry had a wake-up call: as production volume rose, exports fell. This came on the heels of global competition and higher labor costs. This spurred an alliance to regather the industry, and Fan Biyan's fish farm is among the 30 pilot projects which has applied a code of good practice in the past two years. She has stepped up efforts to use microorganisms to adjust water quality, and disinfectants to reduce disease outbreaks. Globally, though, tilapia prices remain low.

HAN XUEFENG, SECRETARY-GENERAL HAINAN TILAPIA SUSTAINABILITY ALLIANCE "Having been around for 20 years, Hainan's tilapia industry is actually quite mature. From its seedlings, feed, to processing, operations and exports. This year, we are exploring how to better represent the price differentiation of Hainan's tilapia, according to its quality, at the international market."

Han Han, who founded the first China-based sustainable fishery and aquaculture NGO, says presently, only a tiny portion of small-scale farmers comply with the set of good standards.

HAN HAN, FOUNDER AND EXECUTIVE DIRECTOR CHINA BLUE SUSTAINABILITY INSTITUTE "From a technical aspect, I believe the farmers should be facilitated to grasp more technology in terms of automatic sensors to monitor water with precise data and record their daily practices. In terms of the institutional aspect, we believe individual farmers should be better organized together in a way that they can access more up to date information about the market, technology, and can also synchronize their practices to face challenges stemming from natural disasters or disease issues."

This unique bottom-up approach, according to Han Han, is crucial, as over 80 percent of Hainan's tilapia production comes from small-scale farmers. But one step at a time. Everyday, Fan Biyan records what she feeds her fish, the medicine used, water temperature and oxygen level of her four ponds, all in a log book this is a start towards a more sustainable fish farming journey. WLT, CGTN, Wenchang in Hainan Province.