Eat a fish, save a rainforest
Why is all of this fishy data so important? Because, Hilborn stressed, the world's growing population -- and its growing appetite for meat -- is going to have increasing impacts on the environment. This is where the energy efficiency of a fish comes into play, or how much edible protein you get for the amount of energy (typically fossil fuels) invested in production. The efficiency of 29 North Atlantic fisheries (9.5 percent) is much higher than any type of landlubbing livestock (pork comes in at 5.6 percent; chicken, 2.9 percent; and beef, 1.9 percent). When it comes to greenhouse gas emissions from production, fisheries are on par with most other livestock except gassy beef. Hilborn used the Atlantic herring fishery to calculate this, which uses mechanized purse-seine methods to pull fish onto boats, the primary source of its greenhouse gas emissions.
One-quarter to one-third of the world currently gets its protein primarily from fish. About half of increased food production comes from chopping down undisturbed forests. "If we stopped fishing," Hilborn said, "we would need to convert a lot of rainforest" to agricultural production to cover the 82 million tons of fish landed in 2006 alone.
Now Hilborn isn't advocating buying into the "Big Lie" that "if you manage fisheries well, there is no impact." Fishing will lower the number of fish. Ecosystems will be changed. Some species will be depleted.
Nevertheless, Hilborn calls foul on the "very different standards that we apply" to food produced on land versus caught in the sea. He argues that terrestrial farming lowers biodiversity in a way that can't compare with marine systems. That means fishing reduces the number of species present in a given area (its biodiversity) by around 30 percent. How much does land-based agriculture lower biodiversity? Very few studies exist to offer comparison, though bird diversity does go down as agricultural intensity rises. Imagine, however, a thriving, "biodiverse" organic vegetable field, and then imagine the lush West-Coast temperate rainforest that the organic farm eventually replaced. That complete of a transformation typically doesn't occur when an area of the sea is fished. The ecological integrity of the ocean remains after the fishin' boats putter away.
Daqui
Hilborn's notion of eat a fish, save a rainforest is based on a tally he's trying to develop for fish, cattle, pigs and chickens. That tally:
- Considers the resources used before one or the other ends up on the dinner table. Included could be such things as the fresh water needed and petroleum used in fertilizer to raise feed or grow pasture lands. On the fishing side would be such things as the petroleum needed to fuel vessels.
- Adds up the degradation such as manure in waterways and soil erosion from raising farm animals vs. garbage dumped at sea and oil or chemical spills from fishing.
- Totals the greenhouse gas emissions that result from both activities.
Daqui
Uma teoria interessante sobre a eficiência da produção de alimentos.
O que comer: carne ou peixe?
Há um problema importante para a discussão, é que os valores dependem muito dos exemplos utilizados na comparação.
Quando se utiliza, por exemplo, um peixe proveniente de uma pesca de arrasto, o custo ambiental proveniente dos combustíveis fósseis é bastante elevado quando comparado com os sistemas de produção de carne. Este artigo demonstra que entre um bacalhau selvagem (pesca de arrasto), um salmão de aquacultura e um frango de aviário, o produto energéticamente mais eficiente é o frango.
Mas há ainda uma série de pressupostos e é difícil de ter valores de comparação fidedignos. Aliás, os frangos de aviário produzidos em Portugal podem ser bastante diferentes dos frangos dos EUA, o que altera o resultado e as conclusões de qualquer estudo.
O melhor, para já, será sempre comer menos animais e mais plantas!
One-quarter to one-third of the world currently gets its protein primarily from fish. About half of increased food production comes from chopping down undisturbed forests. "If we stopped fishing," Hilborn said, "we would need to convert a lot of rainforest" to agricultural production to cover the 82 million tons of fish landed in 2006 alone.
Now Hilborn isn't advocating buying into the "Big Lie" that "if you manage fisheries well, there is no impact." Fishing will lower the number of fish. Ecosystems will be changed. Some species will be depleted.
Nevertheless, Hilborn calls foul on the "very different standards that we apply" to food produced on land versus caught in the sea. He argues that terrestrial farming lowers biodiversity in a way that can't compare with marine systems. That means fishing reduces the number of species present in a given area (its biodiversity) by around 30 percent. How much does land-based agriculture lower biodiversity? Very few studies exist to offer comparison, though bird diversity does go down as agricultural intensity rises. Imagine, however, a thriving, "biodiverse" organic vegetable field, and then imagine the lush West-Coast temperate rainforest that the organic farm eventually replaced. That complete of a transformation typically doesn't occur when an area of the sea is fished. The ecological integrity of the ocean remains after the fishin' boats putter away.
Daqui
Hilborn's notion of eat a fish, save a rainforest is based on a tally he's trying to develop for fish, cattle, pigs and chickens. That tally:
- Considers the resources used before one or the other ends up on the dinner table. Included could be such things as the fresh water needed and petroleum used in fertilizer to raise feed or grow pasture lands. On the fishing side would be such things as the petroleum needed to fuel vessels.
- Adds up the degradation such as manure in waterways and soil erosion from raising farm animals vs. garbage dumped at sea and oil or chemical spills from fishing.
- Totals the greenhouse gas emissions that result from both activities.
Daqui
Uma teoria interessante sobre a eficiência da produção de alimentos.
O que comer: carne ou peixe?
Há um problema importante para a discussão, é que os valores dependem muito dos exemplos utilizados na comparação.
Quando se utiliza, por exemplo, um peixe proveniente de uma pesca de arrasto, o custo ambiental proveniente dos combustíveis fósseis é bastante elevado quando comparado com os sistemas de produção de carne. Este artigo demonstra que entre um bacalhau selvagem (pesca de arrasto), um salmão de aquacultura e um frango de aviário, o produto energéticamente mais eficiente é o frango.
Mas há ainda uma série de pressupostos e é difícil de ter valores de comparação fidedignos. Aliás, os frangos de aviário produzidos em Portugal podem ser bastante diferentes dos frangos dos EUA, o que altera o resultado e as conclusões de qualquer estudo.
O melhor, para já, será sempre comer menos animais e mais plantas!