SARF106 - A Risk Benefit Analysis of Mariculture as a means to Reduce the Impacts of Terrestrial Production of Food and Energy

The world’s population has been predicted to rise to over nine billion by 2050 (e.g. FAO, 2009a; Lutz and Samir, 2010), with most of this increase predicted to occur in low and middle income (developing) countries (Alexandratos and Bruinsma, 2012; Government Office for Science, 2011; Lutz and Samir, 2010). The proportion of the population living in urban areas and income levels are also expected to rise (with at least 3 billion people entering the global middle classes) which is likely to increase demand for more nutritious and higher quality foods (i.e. more resource-intensive foods such as meat and vegetable oils; Searchinger et al., 2013 and references therein).

The question of how to achieve such increases in food production to feed this larger, increasingly affluent population, whilst ensuring sufficient food calories to adequately feed the entire global population, in a sustainable manner (i.e. that ensures food production that contributes to inclusive social and economic development whilst reducing environmental impacts and pressures on limited resources), is the subject of current discussion and research (e.g. Searchinger et al., 2013; Alexandratos and Bruinsma, 2012; The Government Office for Science, 2011). An increased global population will also necessarily have greater energy requirements.

The Scottish Aquaculture Research Forum (SARF) and WWF-UK commissioned this study to investigate whether the pressure on land and freshwater for future food and energy resources, and impacts on the climate, related to greenhouse gas (GHG) emissions, may be reduced through expansion of global mariculture. The study has undertaken a high level assessment of the ‘environmental footprint’ of global mariculture and terrestrial-based food and energy production systems through the collation and assessment of available Life Cycle Assessments (LCA) for key food products (beef, pork, chicken, freshwater finfish, marine finfish, shellfish and crustacean species) and biomass (terrestrial and algal) for energy production. The outputs of the footprint comparison were then used to assess the risks and benefits of increasing global mariculture, through the development of projected future scenarios in which mariculture contributes differing proportions of projected future food requirements. The analysis also qualitatively considered the socio-economic and wider environmental risks and benefits (e.g. in relation to ecosystem services) of global mariculture expansion, where expansion may occur geographically and whether future technological developments may help mitigate against identified impacts.

The study identifies the key uncertainties and limitations of the risk/benefit analysis and makes prioritised recommendations on how these limitations can be addressed and the analysis developed for more regional or site-specific assessments.