For the research, three adult Bluefin tunas weighing 180kg to 300kg were equipped with trackers.
Taiwanese and US researchers have conducted the study to track the spawning and migration patterns of Pacific Bluefin tuna. This is the first-ever study conducted by researchers of the Fisheries Research Institute Taiwan and Stanford University,
According to the local media, Taiwan is one of the countries that harvest the Pacific Bluefin tuna and one of three species of Bluefin — that can live for up to 40 years, grow more than 4 meters long and weigh up to 700kg.
For the research, three adult Bluefin weighing 180kg to 300kg were equipped with trackers, so researchers could monitor the fish during their 3,000km transit from eastern Taiwan seawater to northern Japan’s Hokkaido Island.
The tracker accumulated a recording time of around 127 days.
The data from the trackers showed that the movement and diving patterns of the Pacific Bluefin differ between day and night.
During the day, the fish swam in depths of 300 meters to 500 meters but would rise to 200 meters-deep water in the ocean’s thermocline layer during the hours of darkness.
Pacific Bluefin are known for their physical strength and ability to elude fishers by struggling in and snapping fishing lines.