Kandasamy Kalamohan had grown tired of the trawlers that he and his fellow fishermen alleged crossed into northern Sri Lankan waters from India, about 50 miles away, destroying their prawn nets and depleting their supplies of tuna and cuttlefish.

So last year, he joined a nascent, fast-growing industry: sea cucumber farming. Supplied by a nearby Chinese-owned hatchery, he grows the barrel-shaped creatures that live on the bottom of the sea in his aquatic farm for export to China, where the delicacy sells for hundreds of dollars per kilo.

“Because of the Indian trawling, there are fewer fish in the sea,” said Kalamohan, 48, who previously owned two small fishing boats. “I wanted to start something on my own and this is a very profitable business.”