Success in breeding high-end fish Kue-Tama and Tamakai — World's first completely closed circulation land-based aquaculture system

On February 13, the town of Tsuno in Miyazaki Prefecture, Kake Educational Institution's Okayama University of Science, NTT East (Nippon Telegraph and Telephone East Corporation), and NTT West jointly announced the world's first successful rearing of Kue-Tama (Epinephelus bruneus × Epinephelus lanceolatus) and Tamakai (Epinephelus lanceolatus) in a completely closed circulation land-based aquaculture system. Kue-Tama is a cross between E. lanceolatus (Japanese name "Tamakai"; the world's largest member of the grouper family) and E. bruneus (a high-end fish). Based on this success, the four parties plan to move forward with the establishment of a full-scale mass production system for E.lanceolatus, which has been shown to have particularly a high survival rate and a high growth speed.

Since December 2022, the four parties have been working to create a new fishery industry in the town of Tsuno, as part of the "Fisheries Dream Future Project." Since March 2023, they have been experimenting with Kue-Tama and Tamakai for nine months at a demonstration aquaculture facility, using information and communication technology (ICT) and suitable environmental water (artificial seawater).

In this initiative, Kue-Tama and Tamakai, which had never before been successfully cultured in a completely closed land-based aquaculture system, were selected from the grouper family, which is favored as a high-end fish in Japan and other Asian countries. Both fish species were experimentally cultured for approximately nine months in two 7.4-ton water tanks in a demonstration aquaculture facility completed in Tsuno in late March 2023.

With regard to the aquaculture environment, the four parties are working to improve the growth speed and increase the efficiency and optimization of production-related work by combining the optimal environmental water, aquaculture know-how, and aquaculture plant systems possessed by Okayama University of Science with the ICT of the NTT East Group.

Additionally, by providing remote guidance from Okayama University of Science to the town of Tsuno, the project aims to develop local aquaculture human resources and acquire their skills and know-how.

In this test aquaculture of Kue-Tama and Tamakai, the latter was confirmed to have a high survival rate of 94.2%. Moreover, its growth speed was confirmed to be approximately three times the typical growth speed in normal aquaculture. In particular, the high productivity achieved is a significant achievement for future mass production and commercialization. Although the keepers involved in the test breeding had no aquaculture experience at all, they were able to participate in the aquaculture work at the site without anxiety. The environmental and fish culture conditions that affect fish growth, including water quality elements, were managed through compilation of their data and visualization and precise remote-control guidance was made available by Okayama University of Science. As a result, the four parties believe they have been able to implement an unprecedented level of aquaculture while building their techniques and know-how.

Tamakai in particular was confirmed to have high productivity as a result of these advancements, along with the advanced and brandable characteristics that it originally has. The four parties plan to focus on this species in the future.

Going forward, the aim is also to establish data-driven automatic control of the growing environment using the collected data and a real-time remote control guidance system at a higher level. Based on the results of this project, the four parties, in cooperation with the Tsuno Fisheries Cooperative and local fishery companies, will promote and realize the "Fisheries Dream Future Project" by establishing a full-scale mass production system for Tamakai using a completely closed circulation intelligent land-based aquaculture setup.

Simultaneously, efforts will be made to utilize the processing plant scheduled for completion this spring, realize the commercialization and sale of new specialty products from Tsuno, and promote the creation of new regional brands.