Fish numbers outpace human population

http://www.newscientist.com/article/dn16692-fish-numbers-outpace-human-population.html
Fish numbers outpace human population

17:50 02 March 2009 by Debora MacKenzie
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It's increasingly likely that the fish you eat was farmed not caught wild, according to the latest statistics of the UN Food and Agriculture Organization.
The group's two-yearly assessment of world fisheries, published today, comes with mitigated good news.
The outlook for wild ocean fish remains gloomy: 80% of all fisheries are at or beyond their maximum yields, and over-fishing continues to climb. Yet the amount of fish available to eat is growing faster than the human population, thanks to a boom in fish farming.
The FAO calculates that, for the first time, fish farms produce half the fish we eat, up from less than a third in 2002. With wild-catch fisheries maxed out, any more increases in fish production will depend on farms.
Problems in the wild?
It is unclear from the FAO data whether fish farms are indirectly putting more pressure on wild stocks.
Many farmed fish eat fishmeal and oil, made from small species like sardines. The FAO says the tonnage of these species consumed has trebled since 1992, but does not say whether this is a consequence of fish farming, or because the fish are being used for other purposes.
In a parallel report, international fisheries pressure group Oceana charges that by relying on wild-caught species like sardines, which now constitute one third of world fisheries, fish farms are starving larger predators, including tuna, marine mammals and seabirds.
The FAO observes that the unrestricted competition between companies is a waste of energy: too many boats mean that fewer fish are caught per litre of boat fuel. Meanwhile, boat owners buy more powerful, less efficient engines to beat the competition.