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| Amberjack |
He started his research concerning the availability of trace minerals in feed ingredient, and the results of this research have lead to further research areas, namely the development of environment friendly aquafeed and development of low/non fishmeal aquafeed. Recently he succeeded with non-fishmeal feed for yellowtail experimentally. He has published more than 200 papers in scientific journals.
by Professor Shuichi Satoh, Tokyo University of Marine Science and Technology
Amberjack culture in Japan started at the Ado pond in Shikoku Island approximately 90 years ago. Currently, there are three amberjack species being used for aquaculture in Japan namely, the yellowtail Seriola quinqueradiata, greater amberjack Seriola dumerili, and the yellowtail kingfish Seriola lalandi. The annual production for these three species of amberjacks is at around 150 thousand metric tonnes.
Yellowtail comprises the highest percentage of the total production at 70 percent followed by greater amberjack at 28 percent while yellowtail kingfish contributes only two percent to the total production.
The seed stock for use in the aquaculture production of amberjack comes from the wild. Wild-caught juveniles weighing approximately 30-50 grammes are raised for 20 months or more in an aquaculture setup until they reach marketable size. For yellowtail, the harvestable size is four-kg or bigger while for greater amberjacks, it is 3-3.5kg and for kingfish yellowtail, it is three-kg or bigger. Breeding amberjacks in captivity has been successful and hatchery-produced seed stock can be readily made available. However, wild populations of juvenile amberjacks are still abundant around Japan thus they are the preferred seed stock and are still being widely used for aquaculture.
Up until the 1990’s, there were abundant supplies of sardines and mackerel caught from the wild hence these were primarily used as feeds for yellowtail culture. In large scale or commercial aquaculture, the increase in feeding has also increased the deposition of feeds, feces and other organic matter at the bottom of the holding area resulting to eutrophication and harmful algal bloom which in turn causes red tide. Because of these concerns, the Fisheries Agency of Japan recommended the use of moist pellet for marine aquaculture. Using moist pellet in aquaculture has significantly improved the condition of the culture environment.
To read the rest of our expert topic on Amberjack, click here to see the full in page article in International Aquafeed.
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