Taiwan has received data from a yellowfin tuna that it tagged and released into the ocean last year as part of its study into the fish’s migration habits, a researcher said yesterday.
The tuna, one of 786 that were hatched and released by a local fisheries institute, was caught by Japanese fishermen on April 28 in the waters off Amami Islands, which are located between Okinawa and Kyushu, southern Japan.
The fishermen sent the tag from the fish to the Japan Fisheries Agency, which passed on the data to the Taiwan Coastal and Offshore Resources Research Center of the Fisheries Research Institute, the center’s director, Wu Lung-ching (吳龍靜), said.
The data, which is vital in the research of yellowfin’s movement in the waters around Taiwan and their migratory habits, showed that the tuna had traveled the longest distance ever recorded for yellowfins released from Taiwanese hatcheries, Wu said.
He said that each of the yellowfin tuna weighed around 2kg and were 35cm long when they were released on Oct. 25 in the waters southeast of Lamay Island, a coral islet that lies 15km west of Donggang (東港) in Pingtung County.
But surprisingly, the fish that was caught was still the same size after six months, he said.
The institute is trying to come up with an explanation for this bizarre finding, he said.
Wu said it was important to know the migratory path of yellowfins in the waters off southwestern Taiwan to promote conservation of the species.
Researchers are trying to determine whether yellowfin tuna swim from Penghu Islands off southwest Taiwan northward to Japan along the Taiwan Strait, or if they swim to the east coast of Taiwan then follow the Black Tide to Japan, Wu said.
The research could help the institute devise plans to prevent overfishing of yellowfin tuna in waters around Taiwan, he said.
The results of the research will be shared with the international community to develop integrated conservation of marine resources, he added.
Wu said about 1,000 tonnes of yellowfin are caught in Taiwan each year, accounting for a small percentage of the 800,000 tonnes taken worldwide annually.
Yellowfin tuna are widely distributed in tropical and subtropical waters of the Atlantic, Pacific and Indian Ocean.
They are also found in Canadian waters along the edge of the Gulf Stream and Georges Bank, the Scotian Shelf and the Grand Banks.
RSS