A study recently published in Proceedings of the National Academy of Sciences.
Get it right on fish intensity, get it right for aquaculture
Tuesday, March 13, 2018, 10:00 (GMT + 9)
A study from Bangladesh shows that intensification of aquaculture production can reduce some environmental impact, producing more using less.
In June 2015 centre director Johan Rockström argued that "if we get it right on food, we get it right for both people and planet". He was definitely on to something. Any hope of feeding a growing human population while living within planetary boundaries rests on the ability to transform a currently unsustainable food production system. As demand for food grows, there is an urgent need to limit the environmental consequences of its production by producing more using less. This concept is known as sustainable intensification.
Much focus has been dedicated to how it can help agriculture, the most significant source of environmental degradation, but attention is now being broadened to also include seafood production and aquaculture in particular. Over the past three decades, aquaculture has risen from relative obscurity to become a major component of the global food system. The sector now provides more than half of all fish destined for direct consumption by humans worldwide.
Intensification in Bangladesh
Most assessments of the potential for sustainable intensification rely on only one or two indicators such as greenhouse gas emission or eutrophication. This means that several environmental impacts of the production and distribution of an item remain unaccounted for.
In a study recently published in Proceedings of the National Academy of Sciences centre, researcher Patrik Henriksson with colleagues from Bangladesh, the US, and Spain have taken a critical look at the environmental impacts of aquaculture intensification in Bangladesh.
Aquaculture intensification is of particular importance to Bangladesh as it has a higher population density than any other non-city country in the world. There are virtually no possibilities for further agricultural expansion, and arable lands are being lost to urbanization at an alarming rate. Ecosystem degradation and overexploitation of both marine and freshwater ecosystems further threaten future fish production from capture fisheries.
As a consequence, 55 per cent of the fish produced is already being farmed. The intensification of aquaculture is therefore likely to not only continue but to be essential for food production. That also raises the stakes when it comes to the manner in which it is being produced.
Less negative impact
By conducting a Life Cycle Assessment of 2,678 farms, the authors measured how intensified aquaculture production in Bangladesh affected impacts of global warming, acidification, eutrophication, freshwater ecotoxicity, freshwater consumption, and land occupation.
Based on this, the researchers found that the intensification only had a negative impact on eutrophication, acidification, and freshwater ecotoxicity, while it was indifferent in terms of global warming and land use, and had a positive effect on freshwater consumption.
"This indicates that the intensification of aquaculture does not result in escalating environmental consequences across the board. It may even help to reduce certain impacts," Henriksson explains.
More fish, less feed
Overall, the researchers believe that more efficient farm management and food provisioning can lead to even further improvements in aquaculture production. That means producing more fish using less feed.
"Adoption of a range of simple management practices that also improve farm economic performance has the potential to contribute to sustainable intensification," Henriksson says.
Improvements in feeding efficiency can be achieved by a variety of means including better feed formulation, use of appropriate feed servings (pellet size and structure), and better on-farm feed management practices such as storage and feeding rates. This would result in some of the largest improvements in the environmental performance of most aquaculture systems.
However, Henriksson and his colleagues warn that with increased intensification a proportionately larger share of the environmental impacts occurs in telecoupled locations outside the farm site and even the other side of the planet. The consequences of different impacts also need be seen at different geographical scales. Global warming acts on a global scale, acidification on a continental scale, and eutrophication, freshwater ecotoxicity, freshwater consumption, and land occupation on a provincial scale.
"Consideration of environmental impacts up to and including the point of consumption therefore remains an important area for future research," they conclude.
Source: Patrik Henriksson, lead author
Link to publication