WILL GLOBAL WARMING BENEFIT NORTHERN FISHERIES?Edit
FISHERY EXPERTS SEE LIGHT ... AND CLOUDSEdit
(This article is published to the Wikia by the author and copyright-holder, Menakhem Ben-Yami, and has also been published in WORLD FISHING, August 2005)
Experts in fishery economics, management, marine biology, oceanography and climate devoted 2 days to trans-disciplinary thinking on the influence of past and future climate shifts on fisheries at the GLOBEC workshop “Economic Effects of Climate Change on Fisheries” held in Bergen on June 20-21.
Global-warming enthusiasts learned that warming-cooling cycles were occurring throughout the written history and earlier, affecting fish stocks for better and for worse, and that collapses of fish populations were happening, overfishing or not.
“Seventy years of warming may be followed by cooling as it used to be before. …we should pay more attention to the relative influence of management steps and climatic variations on fish stocks” - said Dr. Svein Sundby of the Bergen Institute of Marine Research, speaking on long-term effects of climate change on fish populations and their forage organisms in the NE Atlantic. “The collapse in the 1950s-1960s of the Norwegian herring stock was a combination of cooling and overfishing” – said Sundby.
Ragnar Arnason of the University of Iceland and Torbjorn Lorentzen of the Bergen Centre of Fishery Economics produced models, and Prof. Wiliam E. Schrank reported on a study, all indicating correlation between warm periods and good northern fishing. Arnason predicted improvement in Icelandic landings, and Lorentzen said that both Norwegian herring and mackerel would react positively. “With such optimistic forecast - Arnason asked - does it make sense to take expensive measures to reduce global warming?”
In the Barents Sea fisheries, “biological and economic impacts of relatively small changes in management regimes – reported Dr. Arne Eide of the University of Tromso – may be more pronounced than the physical, biological and economic changes caused by global warming”.
“The abundance of California sardine is related to environmental fluctuations – said Jerrold Norton of the Pacific Grove, Calif., Southwest Fisheries Science Center – therefore, ecosystem-based management should monitor longer range physical and biological changes in the system”.
Intellectual exercises in mathematical modelling of possible future scenarios contained high level of uncertainty and little data, hence their relevance to real life fisheries seems only incidental. Some papers contained information on actual economic effects of climate change on fisheries, though.
Prof. Rognvaldur Hannesson of the Bergen Centre for Fisheries Economics, the organiser and leader of the Workshop, examined different scenarios and found that, if temperature change would force stocks from one country’s EEZ to another’s, during such “exodus” shared migrating stocks might be overfished by the competing countries.
Samuel Herrick of the La Jolla, Calif. Southwest Fishery Science Center described environmental influences and economic effects on California fish and invertebrate landings; Thorir Sigurdson of the University of Akureiyri in Iceland ascribed the departure of Atlanto-Scandian herring to warmer waters, and its effect on the Icelandic economy, to an incursion of the cold East-Icelandic current. “Maybe this summer herring started coming back” – said Sigurdson. Kathleen Miller of the U.S. Center for Atmospheric Research said that international management of highly migratory stocks, such as tropical tuna, should involve flexible responses to climate variability.
Prof. J.R. McGoodwin of the University of Colorado, Friday Nyaja of the Malawian Fisheries Department, and M.Ben-Yami of Israel described how climatic shifts and the resulting changes in fishery resources actually affected fishing people and their communities.
McGoodwin has studied for years people of high-latitude regions. In Alaska, the commercial sector is less resilient to conditions change than subsistence communities. Even with poor salmon runs, Yup’ik Eskimo catch in summer the little they need for the whole year. Still, radical and major decadal changes may cause unpredicted consequences.
“In Iceland – said McGoodwin - the cycling boom-and-bust capelin fishery interacts on fishmeal markets with the El Nino – La Nina effects on the Peruvian anchoveta fishery. A wrong combination of the above hurts Icelandic fishermen limited by their capelin-quotas. It’s the other way around when El Nino depresses the anchoveta fishery and capelin stock is up.
McGoodwin’s report implies criticism of the Icelandic quota system, as affecting social cohesion, favouring large-scale operations and frustrating small-scale fishermen by damping their flexibility to shift to other species and fisheries for which they own no quotas, and their sensitivity to fish reactions to weather and climate-forcing. It concludes in some specific management recommendations.
Njaya told how the fisheries of Lake Chilwa, Malawi, is affected down to occasional collapses by repeating climate-forced water-level variations and their ecological consequences. “In such environments climatic variations’ impact is much more important and radical than fishing effort” – said Njaya. When fishery collapses there’s a total loss of income to 3,000 boat-and-gear owners, 7,000 crews, 3,700 traders and the workers and suppliers associated with boat-building industry. His report included some financial evaluation of losses caused by climatic phenomena.
Ben-Yami reported how some 50 years ago a minor climatic shift brought about a spell of poor fishing years triggering privatisation process in Israel’s trawling sector and social dislocation among co-operatives and collective villages.