The protein puzzle
A proteína é uma das componentes mais importantes da alimentação. Por isso cada vez mais se discute qual a forma mais eficiente de produzir a proteína animal.
O tema tem gerado várias discussões devido a dificuldade em avaliar quais os custos ambientais.
É difícil de ter uma visão completa dos processos e capacidade de comparar diferentes estudos, e há ainda um elevado desconhecimento sobre alguns impactes em determinados ecossistemas, como o marinho.
Há algum tempo que tenho andado à procura de uma resposta para esta questão. E aqui está um relatório que compara a produção e o consumo dos alimentos considerados como a fonte de proteína animal (carne, produtos lacticínios e peixe) na União Europeia.
Este post ficou gigante...mas a informação é tão interessante que não consigo resumir mais.
O consumo de proteína animal na UE é elevado, como seria de esperar, mas há diferenças significativas no impacte ambiental dependendo no tipo de animal e conforme o tipo de produção. A avaliação de desempenho ambiental foi feita de acordo com 2 parâmetros principais: emissões de gases com efeito de estufa e área de terra utilizada.
Average EU consumption of animal protein per capita is about twice the global average. Meat consumption in Europe is twice the world average; for dairy produce it is three times higher. Average EU consumption of meat, dairy and fish has increased strongly over the last 50 years.
The total per-capita protein consumption (including from vegetable sources) is about 70% higher than needed. This, in itself, probably would have no adverse effects on human health, if not for the associated intake of saturated fatty acids, which lead to increased risks of cardiovascular diseases. The average intake of saturated fatty acids is about 40% higher than recommended.
Around 10% of the EU’s greenhouse gas emissions are caused by livestock production. Together, the beef and dairy sectors are responsible for two thirds of these emissions.
The total per-capita protein consumption (including from vegetable sources) is about 70% higher than needed. This, in itself, probably would have no adverse effects on human health, if not for the associated intake of saturated fatty acids, which lead to increased risks of cardiovascular diseases. The average intake of saturated fatty acids is about 40% higher than recommended.
Around 10% of the EU’s greenhouse gas emissions are caused by livestock production. Together, the beef and dairy sectors are responsible for two thirds of these emissions.
A large quantity of nitrogen fertiliser is needed, each year, to sustain Europe’s high production levels of grass, cereals and other crops. More than 80% of this nitrogen input is lost, leading to various environmental problems, including the loss of terrestrial biodiversity and algae blooms in coastal waters. There are large differences in greenhouse gas and nitrogen emissions between the various animal products and production practices.
Global demand for animal products is expected to increase significantly, in the coming decades, as a result of a growing global population and increasing prosperity.
Global demand for animal products is expected to increase significantly, in the coming decades, as a result of a growing global population and increasing prosperity.
Globally, already around 30% of the total human-induced biodiversity loss is related to livestock production. And capture fisheries are unlikely to be able to contribute to meeting the increasing fish demand.
O estudo tem uma análise geral sobre a produção de peixe e uma das conclusões é que este alimento pode ser uma das opções mais sustentáveis para o fornecimento de proteína animal.
Fish farming of predatory species, such as salmon, uses wild-caught fish as part of the fish feed.
Further innovations in the composition of this feed, but also a switch to an increased consumption of herbivorous fish, would reduce the amounts of wild-caught fish required in fish feed. This would involve only a small increase in agricultural land used in the production of the feed for these additional numbers of farmed herbivorous fish. In this way, wild fish stocks would be protected, could recover and possibly provide higher catches in the future.
The biggest fishery countries in the EU are Spain, Denmark,France and the United Kingdom, which together catch more than half the EU27 total. The biggest fishery countries in Europe, however, are not part of the EU. These are Norway and Iceland, with catches in the same year (2008) of 2.4 and 1.4 million tonnes, respectively.
The EU27 catch from the north-east Atlantic Ocean – the most important region – has declined by about a third since the early 1990s. Catches from other regions, often much further away, have only been able to compensate this decline to a certain extent or temporarily. The decline in landings in the past 15 years can be attributed to a combination of declining stocks and EU policy.
The biggest fishery countries in the EU are Spain, Denmark,France and the United Kingdom, which together catch more than half the EU27 total. The biggest fishery countries in Europe, however, are not part of the EU. These are Norway and Iceland, with catches in the same year (2008) of 2.4 and 1.4 million tonnes, respectively. 
The EU27 catch from the north-east Atlantic Ocean – the most important region – has declined by about a third since the early 1990s. Catches from other regions, often much further away, have only been able to compensate this decline to a certain extent or temporarily. The decline in landings in the past 15 years can be attributed to a combination of declining stocks and EU policy. 
Aquaculture production in the EU27 countries greatly increased between 1950 and 2000, after which it stagnated. The biggest producers are France, Spain, Italy and the United Kingdom (over 10% each). About half of the production consists of shellfish; finfish is equally divided between marine and freshwater species. The shellfish species most produced in the EU27 are mussels, oysters and clams (together 50%), and finfish species are rainbow trout, Atlantic salmon, gilthead sea bream, common carp and European sea bass (EC 2010).
In Europe, about 20% of fish production is from aquaculture, compared with 40% worldwide.
In Europe, about 20% of fish production is from aquaculture, compared with 40% worldwide.
In 2007, European aquaculture as a whole produced about 4% of the global production.
Global aquaculture production is still growing strongly (particularly in Asia). The main causes of this are the relatively low costs of labour and land. Other factors are the stricter regulations concerning location, water consumption and water pollution in EU (Bostock et al. 2008).
The supply of fish in the EU, added up to more than 10 million tonnes, or 22 kilograms in live weight, per capita. This was about 30% more than the global per-capita average and, today, slowly continues to increase.
As only about 50% of the demand in the EU27 is filled by EU production (fisheries and aquaculture), the remainder is imported. Some of the imports are from other European countries, in particular, from Norway and Iceland.
The fish species imported most are salmon, pangasius, tilapia and tropical shrimps.
Declining fish stocks and greater distances travelled to catch these fish, globally, have led to a decrease in energy efficiency of fisheries, over the last decades.
The fish species imported most are salmon, pangasius, tilapia and tropical shrimps.
Declining fish stocks and greater distances travelled to catch these fish, globally, have led to a decrease in energy efficiency of fisheries, over the last decades.
Between 1995 and 2007, the amount of forage fish needed per kg of farmed fish was considerably reduced for several predator species. The global average is already well below 1 kg in forage fish per 1 kg of farmed fish, because global aquaculture is dominated by herbivorous and omnivorous species. However, about 20% of the global fish catch is still being used for fish feed in aquaculture.Although aquaculture competes with agriculture for land (land use per kilogram of protein), farmed herbivorous fish is comparable to that used for poultry (Bostock et al. 2010).
Land use ranged from about 1 m2 per kilogram for milk, soy milk and some vegetable products, to over 400 m2 per kilogram for beef from extensive production systems.Beef, sheep meat and trawled lobster showed by far the highest carbon footprint per unit of weight, although large differences exist within beef production. Low carbon footprints per units of weight were generally found for mussels, some other shellfish, milk, poultry and vegetable products.
Farmed fish is more or less comparable to poultry in environmental impact. Farmed predator fish, such as salmon, usually use more forage fish, compared to vegetarian fish, such as pangasius, although the feed conversions are still being improved. The worst scores are for tropical shrimp and prawn cultivation and fisheries. And the greenhouse gas emissions related to wild-caught fish are determined by fishing method.
In addition to the global problems surrounding greenhouse gases and land use, other issues may also be very relevant, such as animal welfare, eutrophication, emissions of pesticides, the use of hormones, and the depletion of resources.
O mais importante disto tudo são as propostas mais eficazes de aplicar.
O estudo conclui que há 3 opções principais para alterar o impacto da produção animal:
- alteração de hábitos de consumo - consumption shifts, particularly a reduction in the consumption of livestock products, will not only have environmental benefits, but may also reduce the cardiovascular disease burden. This option is easy and robust, but changing consumption patterns is a slow cultural process;
- maior eficiência na utilização dos recursos - improving production efficiency is already common practice, as there are many synergies between enhancing production and reducing costs;
- e produzir com menores impactes locais - more robust production systems with fewer local impacts, generally, lead to higher costs for farmers. However, if done properly, this would lead to lower societal costs by reducing local environmental impacts, animal suffering and public health risks.
E o mais simples que se pode fazer, está ao alcance de qualquer pessoa:
Individual consumers and actors in food production have many opportunities to reduce the impacts of livestock production, independently from government actions.
Consumers could shift to the consumption of products with lower environmental or animal welfare impacts - from red meats and bottom-trawled shellfish towards vegetal sources of protein, poultry and sustainable shellfish.