Friday 25 January 2013

Green Blog: Milestone Looms for Farm-Raised Fish

Sometime this year, we will quietly pass a milestone in human history: the majority of the fish we eat will be farm-raised rather than wild-caught.

In the last 20 years, the production of fish through aquaculture has grown exponentially, while marine fish catches have leveled off. Unless it?s an extraordinary year for marine fishing, in 2013 the lines will cross, and the majority of the fish we eat will come from aquaculture rather than oceans.

Fishing is the only part of global food production in which the tillers and the breeders of the world are not dominant, and this year, the last stronghold of the hunter-gatherers will be eclipsed, according to data from the United Nations Food and Agriculture Organization?s 2012 State of World Fisheries and Aquaculture report.

This is not to suggest that the approximately 45 million people who fish for a living are headed to the history books sometime soon. Fishing is likely to continue to have a large work force even as overharvested wild fish stock in many parts of the world decline and the job itself remains one of the most dangerous.

The reason, as several recent studies show, is that fishing is a ?sticky? occupation. One study found that as years of fishing experience increases, so does job satisfaction and the unwillingness to leave the occupation. In another study, people in the Pacific Island nation of Kiribati were provided with a government subsidy for coconut production as a tool to reduce fishing pressure, and the result was the exact opposite. The extra income from coconuts gave them more time to do what they wanted, which was fishing.

Fishing remains one of the few occupations that people will pay money to do in their leisure time.

While commercial fishing will continue regardless of the growth in aquaculture, it is aquaculture that holds more promise for addressing the Malthusian dilemma of feeding a human population expected to increase by 50% over the next 50 years.

One reason is that aquaculture is the most efficient producer of animal protein. Feed conversion ratios for several aquaculture fish species are approaching 1:1, meaning that for every pound of feed, a fish gains one pound. By comparison, the most efficient farmed animals on land are broiler chickens with a 1.6:1 feed conversion ratio. (One reason is that with a few exceptions like bluefin tuna, fish are coldblooded and thus use less energy than poultry, beef cows and hogs.)

Aquaculture is not without problems, however. The effluents from aquaculture ponds can pollute nearby waters and cause severe oxygen depletion, or eutrophication.

Shrimp aquaculture in particular has caused swaths of mangrove forests to be cleared for shrimp ponds in a number of countries, and this loss of ?green infrastructure? has made these coastal areas more vulnerable to storms and diminished the local ?fish nurseries? that mangroves provide.

Disease in aquaculture is also a problem. Widespread outbreaks of disease occur almost every year, and the overuse of antibiotics and pesticides in aquaculture is a growing issue. Trace amounts of antibiotics and pesticides can remain in some aquaculture products.

To help ensure food safety and sustainability of aquaculture products, third-party certification systems like the Aquaculture Stewardship Council and Global Aquaculture Alliance-Best Aquaculture Practices are growing in popularity, especially among large buyers of aquaculture products like supermarket chains.

We?ve had 12,000 years of learning in agriculture and 60 years in large-scale aquaculture. There is still much that is unknown about domesticating fish and shellfish. But what?s clear is that the shift from foraging to farming is almost complete.

In another century, never-say-quit fishermen and dumpster-diving Freegans may be the only hunter-gatherers left.

Source: http://green.blogs.nytimes.com/2013/01/24/a-milestone-looms-for-farm-raised-fish/?partner=rss&emc=rss

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