SEAFDEC Achieves Groundbreaking Success in Mackerel Tuna Captive Spawning
Historic Milestone: For the first time, the mackerel tuna, known as kawakawa, has successfully reproduced under natural conditions in captivity at a research facility in the Philippines. This remarkable achievement was made at the Southeast Asian Fisheries Development Centre Aquaculture Department (SEAFDEC/AQD) located in Tigbauan, Iloilo, without the use of hormone injections.
A Landmark Successful Spawning Event
The initial spawning event was documented in July 2025, with additional spawning occurrences noted through September, showcasing the potential for cultivating this species in controlled environments.
Tackling Aquaculture Challenges
“Tuna species, particularly mackerel, present unique difficulties in aquaculture due to their migratory nature, rapid swimming speeds, and sensitivity to confinement,” explained Dr. Takahiro Sajiki, deputy chief of SEAFDEC/AQD and co-manager of the Japanese Trust Fund supporting this research. These characteristics have previously hindered successful breeding, compelling aquaculture practices to rely primarily on wild-caught juveniles.
Research Driven by Persistence
This landmark achievement is the result of years of dedicated research and broodstock management at SEAFDEC/AQD. Despite facing initial hurdles such as stress-related mortality and challenges in adapting to captivity, the research team remained committed.
“Instead of relying on artificial methods for spawning, we enhanced broodstock care, monitored the fish closely, and utilized controlled environmental techniques to create conducive conditions for natural reproduction,” stated Ms. Irene Cabanilla-Legaspi, the lead researcher on the kawakawa project since 2020. “Our persistent efforts led to the release of viable eggs by the captive kawakawa within an enclosed tank.”
From Wild to Captive Spawners
Juvenile kawakawa were initially collected using an “otoshi-ami” fish trap in Antique Province. Prior to their transport, the fish were conditioned over several days to prepare them for the stress of confinement and the journey to SEAFDEC/AQD’s facilities.
“Strict transport protocols were implemented to maximize survival, including lowering water temperature, individual handling of each fish, and constant monitoring of water quality,” remarked Dr. Leobert de la Peña, head of SEAFDEC/AQD’s Research Division. These protocols proved successful, as survival rates remained high even three days post-transport.
Optimizing Hatchery Conditions
During their time in the hatchery, the juveniles were kept in tanks with meticulously regulated water quality and feeding schedules to minimize stress and enhance growth and maturation. This careful approach allowed the fish to adapt to captivity and eventually release viable eggs, confirming that kawakawa can complete their reproductive cycle within a fully enclosed system without hormonal intervention.
“This breakthrough brings us closer to establishing a comprehensive culture technology for kawakawa, spanning from egg to larva, juvenile, adult, and back to spawning,” said Mr. Dan Baliao, Chief of SEAFDEC/AQD.
Promoting Sustainable Tuna Production
Valued for its firm flesh and flavor akin to bluefin tuna, kawakawa matures quickly and thrives in coastal environments, positioning it as a promising candidate for sustainable aquaculture. Moreover, it holds high levels of the beneficial nutrient docosahexaenoic acid (DHA).
“By developing reliable breeding and culture techniques for kawakawa, we hope to reduce our reliance on wild-caught stocks and help stabilize tuna production,” Baliao added. However, he noted that further years of research and commitment will be essential to replicate these results and scale them for commercial production.
This innovative research was conducted under the auspices of the Japanese Trust Fund-supported project titled “Development of Full-Life Cycle Culture and Stable Production Technology of Kawakawa (Euthynnus affinis).”
Image Credit: SEAFDEC/AQD
