Imminent collapse of ocean ecosystems refuted
SPC Press Release
Research refutes recent claims of imminent collapse of ocean ecosystems
Friday 15 December 2006, Secretariat of the Pacific Community (SPC), Noumea – Research conducted by an international team of scientists, including SPC’s Oceanic Fisheries Programme Manager, Dr John Hampton, and reported in a paper published this week in Science, refutes claims that ocean ecosystems are on the brink of collapse. Although the new research finds significant decreases in abundance of some large pelagic (oceanic) fish stocks resulting from increased fishing, the picture is not nearly as gloomy as has been previously reported.
The paper, entitled “Biomass, size and trophic status of top-level predators in the Pacific Ocean”, is co-authored by Dr Hampton and three other well-known fisheries scientists: John Sibert of the University of Hawaii, Pierre Kleiber of NOAA Fisheries in Honolulu, and Mark Maunder of the Inter-American Tropical Tuna Commission (IATTC). Unlike the previous studies, which have made exaggerated claims concerning the impacts of fishing, this study analysed all available data assembled by SPC and IATTC for Pacific tuna fisheries from 1950 to 2004, to estimate the impact that fishing has had on Pacific fish populations in the past 50 years. The analysis finds that the situation of different types of top predators, such as tuna and sharks, varies considerably.
“Recent claims of catastrophic reduction in the biomass of top-level predators and the collapse of oceanic food chains have attracted widespread attention and provoked alarm among the lay public,” reports the paper. Dr Hampton notes, “Alarmist and exaggerated claims of stock collapses based on inadequate analyses and data have attracted a lot of attention, but the situation is more complex than that. These reports are dangerous not only because they are wrong, but also because they detract attention from the real management problems facing pelagic fisheries in the Pacific.”
According to the paper, fishing for two important types of tuna – yellowfin and bigeye – is currently at or slightly beyond the maximum sustainable level, while other species are being fished generally within safe limits. Yellowfin and bigeye are threatened, however, by future growth of international fishing fleets. “This is a particularly important issue for SPC’s Pacific Island members, whose economies are heavily reliant on the sustainable use of these resources,” notes Dr. Hampton.
Based on this finding, scientists in two international regulatory commissions – the Western and Central Pacific Fisheries Commission and IATTC – are recommending options to limit fishing for these species. The options include catch and fishing effort limits, time and area closures, and restrictions on the use of floating objects by the purse-seine fishery.
The new findings have been well received by many fisheries researchers and managers. “It is refreshing and encouraging to see Science finally publishing a comprehensive stock analysis carried out by competent and experienced fisheries assessment experts,” says Dr Carl Walters of the Fisheries Centre at the University of British Columbia in Vancouver. Dr Mark Maunder noted that “part of the reason our analysis has credibility in the fisheries scientific community is because we considered all the available data for these stocks rather than just picking and choosing the data that suit our cause, which is in stark contrast to several of the recent pessimistic fishery articles published in the journals Science and Nature”.