ILOILO CITY — A small coastal town in Iloilo has achieved a breakthrough for global fisheries after Filipino scientists recorded the world’s first natural spawning of mackerel tuna in captivity. This milestone could reshape the future of sustainable tuna farming.

Researchers at the Southeast Asian Fisheries Development Center–Aquaculture Department (SEAFDEC/AQD) in Tigbauan, Iloilo, confirmed that mackerel tuna (Euthynnus affinis), locally known as tulingan or kawakawa, reproduced successfully without hormone injections, overcoming a long-standing barrier in tuna aquaculture.

The historic spawning, observed from July to September 2025, marks a significant leap toward full-cycle tuna culture — an achievement long viewed as unattainable due to tuna’s migratory behavior, high-speed swimming and extreme sensitivity to stress.

Because of these challenges, most existing tuna farming operations worldwide still depend on wild-caught juveniles, placing continued pressure on declining stocks.

“Instead of forcing reproduction through artificial means, we focused on refining brood stock care and creating the right environment for natural spawning,” Irene Cabanilla-Legaspi, the lead researcher who has been steering the project since 2020, said.

“This proves that tuna can reproduce naturally in captivity if their biological and environmental needs are met.”

Product of years of research

The breakthrough is the product of years of systematic research, funded by a Japanese Trust Fund, with brood stock sourced as juveniles from fish traps in Antique province.

The fish were subjected to meticulous conditioning, transport, and monitoring protocols to ensure survival and adaptation in enclosed tank systems.

SEAFDEC/AQD chief Dan Baliao described the achievement as a crucial step toward developing full-cycle culture technology, raising tuna from egg to adult and back to egg within a controlled environment.

“Reliable breeding and culture of kawakawa could significantly reduce dependence on wild stocks and help stabilize tuna supply,” Baliao said, noting its implications for food security and marine conservation.

Widely consumed across Southeast Asia, kawakawa is prized for its firm flesh and flavor comparable to premium tuna species.

Unlike larger oceanic tunas, it matures faster and thrives in coastal waters, making it an ideal candidate for environmentally sustainable commercial aquaculture.