Lin Chun-lai bought his grouper farm in southern Taiwan about a decade ago with an eye on mainland China’s growing appetite for live fish. In just a few years, the former electrician made enough money to comfortably support his family of four and even open a small inn.

Then China abruptly banned all imports of grouper from the island, in an apparent attempt at turning the economic screws on Taiwan, a self-governed island that Beijing claims as its own territory. The move cut Lin and other farmers like him off from their main market, putting their livelihoods at risk and dealing a huge blow to a lucrative industry.

"If I don’t farm groupers, what else can I do to live?” Lin said on a recent morning as he stood on a short concrete wall looking out at the 2.5 acres of water, divided into pools, in which he is raising more than 70,000 fish. The groupers were ready for harvest, but since the ban took effect a week ago he has not received orders from fish traders who would normally be calling at this time of the year.