UBC scientist invokes future generations to save tuna populations from collapse

“We must act as if future generations of people are alive and negotiating with us now on catch levels,” says Sumaila, who is presenting his findings with UBC Fisheries Prof. Daniel Pauly at the American Association for the Advancement of Science (AAAS) Annual Meeting in Boston, MA.

Comparing the fate of tuna to that of cod, which helped shape the economies of whole nations in the early 20th century, Sumaila and fellow scientists from Stanford University, the University of New Hampshire and the World Wildlife Fund (WWF) say warning signs are clear that tuna stocks are on the brink of disastrous decline.

“At its peak in 1968, cod fisheries in Atlantic Canada provided US$1.4 billion in revenues,” says Sumaila. “By 2004, they delivered only US$10 million.” He estimates revenues from yellowfin tuna in the Western Central Pacific peaked in 2001 at US$1.9 billion and dropped by 40 per cent in only three years to US$1.1 billion.

Developed countries like the U.S. and Japan have technologically advanced long-line fishing fleets that enable them to harvest adult yellowfin tuna, highly valuable and popular with the Japanese sushi market. Developing countries such as the Philippines, however, have less advanced fleets that target skipjack using purse-seiners and fish aggregating devices while trapping juvenile yellowfin as by-catch.

WWF-Philippines estimates 16 per cent of total tuna catch of the Philippine’s purse-seine fleet are juvenile yellowfin by-catch. If allowed to grow to maturity, this by-catch would total 1.2 million tonnes in marketable biomass, representing over US$1.2 billion a year in lost revenue.

“If we could establish cooperative management agreements that see developing countries receive a share of current adult tuna fishery yields from developed nations in return for allowing the juvenile population to mature, everyone, including future generations of people, will benefit from much greater economic gains while preserving tuna population for the long run,” says Sumaila.