## Topic 1 : Poor catch of commercially important fish species (chum salmon, saury, and Japanese eel) and countermeasures

- FY2012 saw poor catches of commercially important fish species, such as chum salmon, saury, and Japanese eel. Various causes have been suggested, including a rise in the seawater temperature and changes in habitat conditions. It is important to further investigate the causes and, at the same time, take appropriate countermeasures against them.

(1) Chum salmon: The chum salmon populations coming back to Japan’s Pacific coast decreased, and its size became smaller nationwide. In FY2013, the Fisheries Agency will start measures that include research on the behavior of salmon juveniles in coastal areas after they are released in rivers for migration to the sea.

(2) Saury: The landed value of saury was low, because aggregation of saury was not enough for forming fishing ground at the start of the fishing season and there was a decrease in large-sized saury. As the number of foreign fishing vessels catching saury in the high seas is also increasing, it is important to promote international resource management under the Convention on the Conservation and Management of High Seas Fisheries Resources in the North Pacific Ocean (currently under ratification procedures in related countries).

(3) Japanese Eel: The catch of juvenile eels (glass eels) has been poor for three consecutive years in Japan, China, Taiwan, and other East Asian countries/regions. The price of the glass eels for aquaculture seeds has skyrocketed, and the prices of broiled eels and other eel products soared. Since June 2012, the Fisheries Agency has implemented the following emergency measures for eel in collaboration with related countries/entities and organizations: (i) business recovery measures for aquaculture operators, (ii) resource stocking efforts and improvement of habitat environment in rivers, (iii) domestic and international resource management, and (iv) reinforcement of research and study.

Migration routes of saury

Migration routes of Japanese eel

Source: Fisheries Research Agency.

## Topic 2 : Reinforcement of resource management of Pacific bluefin tuna —For achieving sustainable use of resources—

- Japan is the world's largest producer and consumer of Pacific bluefin tuna. Also, Pacific bluefin tuna's spawning ground is presumed to exist around west and south of Japan. Therefore, Japan is not only domestically, but also internationally responsible for the conservation and management of Pacific bluefin tuna resources.

- The Fisheries Agency announced “Actions toward effective conservation and management for Pacific bluefin tuna” in May 2010. It introduced measures for making clear the actual statuses of catches and use of the resources in offshore fishery, coastal fishery, and aquaculture and reducing the juvenile catch.

- Since the amount of catch of juveniles used as aquaculture seeds has been increasing in line with the growth of aquaculture production of bluefin tuna, the Minister of Agriculture, Forestry and Fisheries issued a directive under the Fisheries Act in October 2012 stating that the number of aquaculture sites should not be increased nor should the scale of fish cages for bluefin tuna be expanded from the present level.

- The Fisheries Research Agency has launched a research project to develop technology for producing fertilized eggs of bluefin tuna in a stable manner by using on-shore experimental facility, which is one of the challenges of maintaining a stable supply of artificial seeds (Construction of onshore facility was completed in Nagasaki Prefecture at the end of March 2013.).

Tuna Festival in Nagasaki

## Development of technology for stable collection of fertilized eggs

Stable egg collection technology using large onshore water tanks

Full control of the rearing environment (light and temperature)

- Timely maturation acceleration and spawning inducement in the large water tanks

- Stable egg collection technology for full-life-cycle aquaculture

- Water tanks installed in the vicinity of the Seikai National Fisheries Research Institute (Nagasaki City) in FY2012

Operation commenced in FY2013; 200 age-2 tunas cultivated from onshore water tanks; maturation and spawning induced in two water tanks (20 m in diameter and 6 m in depth)

- Optimum environmental conditions (water temperature, day length, etc.) for spawning in marine fish cages reproduced in the large onshore closed-circuit water tanks to elucidate the maturing and spawning processes and develop technology for stable egg collection

Onshore fish tank of 20 m in diameter to be used for bluefin-tuna-rearing experiments (under construction)