By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM
DECLINE IN OCEAN FISHERIES
The world may be running out of places to catch wild fish. The rapid expansion of global fishing over the past 50 years to meet the demand for seafood has left wild fish stocks nearly depleted.
A group of scientists published an article in 2010 in the online journal PLoS ONE, which is part of the Public Library of Science, titled “The Spatial Expansion and Ecological Footprint of Fisheries (1950 to Present).” The article examines how marine fishing has expanded geographically over time. In the article, the authors map a global trend that until now has mostly been detailed only qualitatively. The results may be particularly valuable in saving some of the world’s most vulnerable species. Our map of those data is worth republishing here.
According to the article, prior to 1880 only sail-powered vessels were used for fishing. Subsequently, fishing was limited to areas directly offshore. When the British began using steam trawlers in 1880, modern industrial fishing vessels using fossil fuels were adopted.
As fishing fleets rapidly became more powerful, they quickly depleted fish populations close to shore. Trawler captains soon found it necessary to expand operations into the entire northeastern Atlantic. At the same time, similar situations were occurring off the coasts of New England and Japan.
While the fish stocks in these areas appeared to recover following World War I and World War II, at the same time fishing boats equipped with diesel engines were emerging. Many of those also had electronic-locating devices used to find more fish and refrigeration systems allowing the boats to stay longer at sea.
The result was that the geographic ranges of global fishing expanded rapidly. In fact, by studying the movements of fishing fleets between 1950 and 2005, the five co-authors of the article determined that fishing expanded southward at approximately one degree latitude each year over that period. Most of that expansion occurred in the 1980s and early 1990s.
Each degree of latitude is approximately 69 miles (111 km). This means that commercial fishing has expanded southward more than 4,000 miles (6,000 km) in the Atlantic and Pacific since 1950.
The Food & Agriculture Organization of the United Nations (FAO) compiles statistics on global fishing. Their data show that the world’s fish catch increased from 21 million tons (19 million metric tons) in 1950 to a peak of 99 million tons (90 million metric tons) in the late 1980s—a fivefold increase. By 2005, however, it had decreased to 96 million tons (87 million metric tons) and further to 87 million tons (79.5 million metric tons) in 2008, even though the fishing pressures had intensified.
According to co-author Daniel Pauly, the principal investigator of the Sea Around Us Project at the University of British Columbia Fisheries Centre, the world’s fish catch is now in decline “because there’s essentially nowhere to go.” He goes on to say that fish catches rose for so many decades only because new fishing grounds were constantly being exploited. Simultaneously, technology made commercial fishing more efficient.
The authors believe that the era of great expansion of fishing grounds is over. The type of expansion of the past is not sustainable and the recent decline in fish catches indicates a global limit to growth. Eventually humans will run out of productive ocean to fish.
We may already be seeing this frightening situation becoming reality. The article states that our unyielding pursuit of seafood in the North Atlantic and Western Pacific has left “only unproductive waters of the high seas and relatively inaccessible waters in the Arctic and Antarctic as the last remaining “frontiers” for commercial fishing.
The article only confirms what scientists, environmentalists and policymakers already know—we must lower the amount of fish taken from the world’s oceans in order to sustain global fisheries. This is the only way to ensure that seafood will still be available for human consumption in the future.
And that is Geography in the NewsTM
Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor.
Sources: GITN 1084 Declining Commercial Fish Stocks, Mar. 11, 2011; Swartz, W., E. Sala, S. Tracey, R.Watson, & D. Pauly, (2010). The spatial expansion and ecological footprint of fisheries (1950 to present). PLoS ONE 5(12); and Eilperin, Juliet. “World is running out of places to catch wild fish, study finds,” Bend Bulletin (OR), Dec. 4, 2010.