A new report by researchers at the University of British Columbia and University of Western Australia has found that global tuna catches have increased more than 1,000 percent in the past six decades, fueled by a massive expansion of industrial fisheries.
Their findings, published in Fisheries Research, by scientists engaged in the Sea Around Us initiative, indicate that these fisheries, which have caught nearly six million tons of tuna annually in recent years, are operating substantially over capacity. Researchers said fisheries have fully exploited or over-exploited populations of tuna and other large fish species and spread out to a point where no new fishing grounds remain to be explored.
According to the research, continuation of tuna fisheries’ catch and revenue at similar levels to present day will depend on long-term sustainable management of the fisheries and fleets exploiting these stocks and ecosystems, as well as the cooperation of over 100 countries engaged in tuna fisheries.
Lead study author Angie Coulter of UBC’s Institute for the Oceans and Fisheries, and her colleagues, have produced the first comprehensive global data set since 1995 that estimates the amount of tuna taken from the ocean and where the fish are being caught.
They found that skipjack and yellowfin are the most commonly caught species of tuna, with combined catches of four million tons annually in recent years. Meanwhile catches of the sushi-favorite blue fin tuna have declined heavily since the mid-20th century, with that species now considered critical.
Researchers also found that the Pacific Ocean provides 67 percent of the world’s total tuna catches, which are mostly taken by Japanese and US fleets. Another 12 percent is caught in the Indian Ocean by mostly Taiwanese, Spanish, Indonesian and French fleets. An additional 12 percent comes from the Atlantic Ocean taken by Spanish, French and more recently Japanese and Korean vessels operating under Ghana’s flag.
Coulter said that hopefully results of this study will encourage stakeholders and policymakers to boost monitoring, share information and agree on coordinated efforts like cutbacks, to foster sustainability of tuna stocks.