The global demand for seafood is high, and over the past several decades the harvesting of wild fish from the oceans has grown into a huge business. In the 1950s most of the world's commercial fisheries were concentrated in the northern Atlantic and Pacific, near the coasts of heavily industrialized nations such the U.S., the U.K. and Japan. Since that time the industry has expanded rapidly southward, and into deeper waters in search of more fish to satisfy the growing market and to compensate for depleted legacy fisheries. Between 1950, the year the United Nations Food and Agriculture Organization (FAO) began releasing an annual report of catch statistics, and the late 1980s the global annual reported catch ballooned from around 18 million metric tons to peak at about 80 million metric tons. Since then, the catch has stagnated, dropping to near 79 million metric tons in 2005.
There is no argument the industry's massive growth has vastly affected ocean ecosystems, but the extent to which this disruption has depleted and continues to deplete the sea's biodiversity has become source of a heated debate within the world of marine fisheries science. At the center of the disagreement, which is highlighted by two recently published studies, is a question: What is the best way to measure the ecological footprint of commercial fishing?
The answer is complicated, due to the inconsistent nature of the data from a large portion the world's fisheries, especially those operated by developing nations. But the authors of a new study published December 2 in PLoS One say they have for the first time quantified, on a global scale, the ecological consequences of commercial fishing. They say their results, gleaned by analyzing global catch statistics, reveal that only the expansion into new fishing grounds has maintained seafood supply by making up for devastating destruction of the biodiversity in older fisheries. Now, they say, there is no more room to expand, and current fishing practices are not sustainable.
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