Life cycle assessment of aquaculture production intensification in Bangladesh
Food production is a major driver of global environmental change and the overshoot of planetary sustainability boundaries. Greater affluence in developing nations and human population growth are also increasing demand for all foods, and for animal proteins in particular. Consequently, there is an urgent need for working towards the sustainable intensification of food production, broadly defined as “producing more using less”. Most assessments of the potential for sustainable intensification rely on only one or two indicators, meaning that ecological trade-offs among impact categories that occur as production intensifies may remain unaccounted for.
A study published by Andreu Rico, researcher from IMDEA Water, and colleagues from universities and research centers from Malasya, Sweden, United States and Bangladesh address this challenge by using life cycle assessment (LCA) to evaluate the potential environmental consequences of aquaculture intensification in Bangladesh. The study uses production data from a unique survey of 2,678 farms, and results show multidirectional associations between the intensification of aquaculture production and its environmental impacts. Intensification (measured in material and economic output per unit primary area farmed) is positively correlated with acidification, eutrophication, and ecotoxicological impacts in aquatic ecosystems; negatively correlated with freshwater consumption; and indifferent with regard to global warming and land occupation. The study indicates that the intensification of aquaculture does not result in escalating environmental consequences across the board. It may even help to reduce certain impacts. Moreover the researchers point out measures to increase production efficiency, for example attempting to produce more fish using less feeds. 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.
Andreu Rico and his colleagues warn that with increased intensification a proportionately larger share of the environmental impacts occur in telecoupled locations outside the farm site and even the other side of the planet. The consequences of different impacts also need to be seen at different geographical scales. For instance, 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. Therefore, they conclude that consideration of environmental impacts up to and including the point of consumption remains an important area for future research.
The study has been published in Proceedings of the National Academy of Sciences, and can be accessed here.