Aquaculture is a growing competitor to capture fisheries, now accounting for almost half of global fish production for human consumption. Sustainable aquaculture appears an appealing alternative to stretched wild populations. However, like all food production it has an environmental impact, which has been quantified in a recent publication.
The authors developed a sustainability index that includes the local food requirements, food economic value, energy, water, and carbon emissions of aquaculture around the world. The index awards a score out of 100 to each country based on its performance in these areas, with 100 being global best practice.
The average score across all producing countries globally was 26. Uruguay achieved the highest score of 74, with all other countries scoring less than 50. China, India, and Indonesia are the biggest players in global aquaculture, and all had scores of 35 or lower. China was responsible for nearly 60% of global aquaculture production, and accounted for just over half of aquaculture’s water footprint and carbon emissions in 2018. As with production of many foods, more developed countries had lower impacts per food produced than developing countries.
Globally in 2018, aquaculture used 1.76 million TJ of energy, 122 cubic kilometres of water, and produced 260 million tonnes of greenhouse gas emissions. This is about the same amount of energy as used annually in Norway, about the same amount of water as needed for a quarter of global wheat production, and 0.47% of total anthropogenic emissions.
This analysis does not capture the nutritional value of aquaculture production, which is particularly important for essential fatty acids. The authors also state the large variation between the environmental impacts of different production systems (e.g., marine versus pond) and species. However, an understanding of the current state of global aquaculture informs targets for improving this, to ensure that the continued expansion of aquaculture will be sustainable.