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Water protection: exploring the depths
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Issue October 2013
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How can we make aquaculture more sustainable?Is livestock welfare ensured during transportation? Do hens have enough space to move around? It seems that we are very willing to ask questions about animal welfare in our livestock husbandry systems, for we want to be certain that conditions are humane. And no wonder – we’ve all seen shocking images of abuse. But when it comes to the creatures that inhabit the aquatic environment, it’s a different story. Aquaculture – the farming of fish and shellfish – attracts much less interest from the public. And yet aquaculture can have extremely harmful impacts on animal health and the environment. So what can we do to make aquaculture more sustainable? That’s a question for the experts at the Oeko-Institut.
Aquaculture is a growth industry. Global production of fish from aquaculture has increased steadily over recent years, from 27.6 per cent in 2001 to 40.1 per cent in 2011, according to the Food and Agriculture Organization (FAO). The FAO’s statistics, which cover a range of different marine creatures – fish, crustaceans, sea cucumbers and amphibians – quote a global production figure of 62.7 million tonnes for 2011: almost twice the figure for 2001 (34.6 million tonnes). This strong growth is a response to rising demand for fish, but also reflects the stagnating yields from marine fisheries, which are partly the result of overfishing.
But aquaculture is no panacea for these problems, for it can have many adverse impacts on marine fauna and the environment. “Without proper closed-loop recycling and recovery systems, residues such as fish excrement, antibiotics and hormones can enter our waters,” explains Martin Möller, Deputy Head of the Sustainable Products and Material Flows Division at the Oeko-Institut. “What’s more, in South-East Asia, the construction of aquaculture facilities, such as ponds for prawn farming, has led to substantial interventions in the environment.” In addition, large amounts of fish are processed into fishmeal to be fed to larger carnivorous fish in aquaculture operations: as Martin Möller explains, it takes between two and five kilos of other fish to produce one kilo of farmed salmon, for example – and that’s really not sustainable. What’s more, rearing conditions often leave a lot to be desired. Poor conditions can result in disease, injury and behavioural disturbances. Making matters worse, fish sometimes escape from fish farm facilities, posing a genetic threat to wild fish populations. Aquaculture facilities also require large amounts of water and energy, which has a negative impact on their environmental performance.
Asia is the world’s centre of aquaculture, accounting for 90 per cent of global production, compared with just 4 per cent for Europe. “The FAO has produced a list of the world’s top 20 aquaculture producers of food fish for 2011, and it includes only two European countries – Norway and Spain,” says Martin Möller.
“But of course, fish are reared in aquaculture facilities here in Germany as well.” Germany’s total output amounted to around 19,600 tonnes last year, according to the Federal Statistical Office. And although it is the Asian facilities which attract most criticism for alleged poor welfare and damage to the environment, Germany’s fish farms are not above reproach. “In Germany too, there are open systems which can cause environmental problems,” says Martin Möller. “So we need to take action to ensure that Germany’s aquaculture systems are sustainable as well.”
The Oeko-Institut is making an important move in this direction. It is acting as scientific advisor to ten research projects on aquaculture systems supported by the German Federal Foundation for the Environment (Deutsche Bundesstiftung Umwelt – DBU), assessing them in the light of sustainability criteria and identifying their potential for improvement. “The DBU is keen to support user-friendly, innovative technologies,” explains Martin Möller. “Some of these projects aim to increase energy and resource efficiency or introduce environmentally sound methods of feed production.” For example, one of the projects looks at ways of improving water treatment in closed-loop systems, while another investigates options for using by-products from carp farming in feed production. The use of new species in aquaculture is another area of research. “Until now, fish farming here in Germany has focused almost entirely on two species,” says Martin Möller. “Germany’s total output of around 19,600 tonnes of farmed fish comprises around 11,800 tonnes of trout and around 6,000 tonnes of carp.” The Oeko-Institut’s researchers will be monitoring, evaluating and providing consultancy services for the ten projects for a further year. “These projects constitute important steps towards more sustainable aquaculture,” says Martin Möller. “We hope that some of the techniques being pioneered will be incorporated into general fish farming practice over the long term – that would be a very significant success.”
559 different species are reared in aquaculture facilities worldwide.
Dr Jenny Teufel is also exploring sustainability issues in fish production. As part of a research project commissioned by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, she and her colleagues at the Oeko-Institut have carried out a Product Carbon Footprint analysis of selected fish and shellfish all along the production chain, from larvae breeding to retailing of the final product. They investigated salmon reared in conventional aquaculture in Norway, pollock from deep-sea fishing in the North Sea, a type of wels catfish, known as Claresse, reared in closed-loop systems in the Netherlands, and Nile perch from artisanal fisheries in Lake Victoria in East Africa. The PCF analysis included an inventory analysis of the air-freighting of the fresh products and the shipping of frozen fish. “Originally, the analysis was to include Black Tiger Shrimps from a fish farm in Thailand as well,” says Jenny Teufel. “But unfortunately, there were problems with data collection here.”
The study found that pollock had the lowest Product Carbon Footprint of all the products investigated, although when the fisheries themselves were compared, pollock was beaten into second place by the Nile perch fishery in Lake Victoria, which uses the most traditional approach to fishing. For all the products analysed – with the exception of air-freighted fish – it is the fishing or farming itself which accounts for the major share of greenhouse gas emissions. “In aquaculture, these emissions mainly come from feed production and the electricity required by the facility,” explains Jenny Teufel. In her view, one of the study’s key findings is the marked extent to which the Product Carbon Footprint varies according to the type of transport used. “We found that fresh fish may not necessarily be the most sustainable supply option,” she explains. “From a climate perspective, air-freighting fish from Africa to Europe is not a sound approach.” For Jenny Teufel, the study for GIZ has answered some of her questions, but it has also raised many new ones. “There is plenty of scope for further research in this area,” she says. “There are still a great many cross-cutting issues that need to be addressed, particularly as regards feed production.” In her view, consumers need to start asking themselves whether it might be better, in terms of sustainability, to give up eating some species of fish altogether, such as tuna from all sources and sole from the Mediterranean or the North-East Atlantic. After all, protecting the environment and living creatures is just as important in the aquatic environment as it is in livestock husbandry on terra firma.