Thursday, January 01, 2009

Fishocide

Pardon the goofy title. I keep trying to create words that did not previously exist in Google, but I'm sure someone got to this one first.


Despite the exploitation round its coasts, Britain, for instance, still landed 750,000 tonnes of Atlantic fish in 2006, two-thirds of what it caught in 1951; even cod is still being hauled from the north-east Atlantic, mostly by Norwegians and Russians. Some British fishing communities—Fraserburgh, for example—are in a sorry state, but others still prosper: the value of wet fish landed in Shetland, for example, rose from £21m in 1996 to £54m ($33m-99m) in 2006. Earnings from fishing in Alaska, in whose waters about half of America’s catch is taken, rose from less than $800m in 2002 to nearly $1.5 billion in 2007. And for the world as a whole, the catch in 2006 was over 93m tonnes, according to the UN’s Food and Agriculture Organisation, compared with just 19m in 1950 (see chart). Its value was almost $90 billion.

The biggest ones have been the first to go. As a result, in over-exploited waters the fish tend to be smaller and younger. Among those caught in the Pacific, the average length of an English sole fell from about 34cm in the 1960s to 30cm in 2002, a Pacific barracuda from nearly 80cm in the 1950s to 65cm in 1970, a bocaccio from over 50cm in the 1970s to nearer 45cm in the 1990s. Whereas record-sized cod 2 metres long and up to 96kg (211lb) in weight were recorded in Massachusetts in the 19th century, and an average of 4.5kg per fish was common in living memory, a big cod is now a rarity in the north-west Atlantic. And when the big fish are gone, smaller varieties become the new catch. “Fishing down” the food web, as the practice is known, resulted in the average length of fish caught off the west coast of Newfoundland falling by a metre between 1957 and 2000, according to an article by Daniel Pauly and Reg Watson, of the University of British Columbia’s Fisheries Centre, in Scientific American in July 2003.

When stocks of familiar fish are exhausted in familiar fishing grounds, man turns towards new fish in new places.

And when the big fish are gone, smaller varieties become the new catch. “Fishing down” the food web, as the practice is known, resulted in the average length of fish caught off the west coast of Newfoundland falling by a metre between 1957 and 2000, according to an article by Daniel Pauly and Reg Watson, of the University of British Columbia’s Fisheries Centre, in Scientific American in July 2003.

Most fish-watchers, however, are uneasy. They see too many signs of overfishing, and too few of recovery.

Another is that, to maintain a balance, big “apex” fish may be as important as small. Many fish take years before they are mature enough to spawn: cod, three or four, sturgeon 20, orange roughy 32. And they may be long-lived: cod can survive to 30, if they are lucky, and sturgeon to 100. Kill the fish at the top and you may get an explosion of smaller ones below, gobbling up much more food than would be eaten by a few big fish of the same total weight. And big fish provide more and better-quality fry. Take the big and leave the young, a common principle of fisheries managers eager to rebuild stocks, may therefore be a mistake. If so, it is not their only one.

The Economist


A quick summary of a great in-depth article that points out the obvious: we're still catching fish, but if they're not the same as the others we caught, aren't we just deferring the disaster?

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Subvert the dominant paradigm, don't be a solipsist.

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