Global fish consumption has already doubled since 1998, but a team led by Rosamond Naylor at Stanford University in California projects a further 80 per cent increase by mid-century. Whether that proves good or bad for the environment and nutrition will rest on what types of fish people choose to eat, the researchers say.
“We talk about fish as a monolithic thing, but actually it’s highly diverse,” says Naylor’s colleague, Beatrice Crona at the Stockholm Resilience Centre in Sweden. “Preferences will play a big role to whether we can convince some people to eat small pelagic fish [such as sardines] or mussels, which are also low [environmental] impact but highly nutritious.”
Supplying the increase in demand with a big expansion of farmed salmon, as pioneered by Norway and Chile, wouldn’t be feasible because of the environmental side effects and inefficiencies of a species so high up the food chain, says Crona. Salmon farming has been linked with water pollution, overfishing to feed them and spreading parasites to wild fish.
Brazil, Ghana, India, Mexico and Nigeria are all expected to more than double the weight of fish they consume by 2050. China, meanwhile, will remain the biggest consumer, expanding its appetite from just over 50 million tonnes of fish in 2015 to just under 100 million by 2050. The growth is expected to decrease meat and dairy demand per person in countries, including China and the US, and raise the intake of iron, calcium and vitamin B-12.
The researchers arrived at their figures using modelling based on UN Food and Agriculture Organization (FAO) data on what fish species people ate in 10 countries that account for 55 per cent of global fish consumption, and on World Bank and International Monetary Fund estimates of future economic and population growth. The researchers considered the 10 countries indicative of global trends. The projections don’t simply assume a linear increase from 2015, but factor in shifts in the species people eat as they get richer.
However, the analysis does rely on some assumptions that are open to challenge. One is that supply perfectly matches demand so prices don’t rise relative to incomes. That rests on the growth in supply “mainly” coming from farmed fish – Naylor says it is likely to grow by 90 per cent – which the researchers say is “plausible” given the industry’s past growth. “We can safely say there is limited scope for increasing uptake of capture fisheries [wild caught fish] globally,” says Crona.
But it isn’t a given that farmed fish can feed growing demand. “As aquaculture accounts for only around 5 per cent of world production of marine fishes, it is challenging for aquaculture to bridge the gap between future demand and supply of marine fishes, especially with the generally negative public images of aquaculture in many countries,” says Junning Cai at the FAO, who wasn’t involved in the study.
Shifts towards plant-based diets in some countries over environmental concerns also mean history may not be a good guide to the future, says Crona. “We are facing an environmental crisis we have not seen before. In response to that, younger generations are making different choices.”
A third factor highlighted by the team is the wild card of climate change, which could disrupt growth in farmed fish through extreme weather.
If the growing demand does materialise, diverse cultural tastes could mitigate negative impacts. “Diversity of fish consumption is high around the world. That flags there is a lot of opportunity in the role ‘blue food’ [food derived from aquatic animals, plants or algae] can play in food systems. It’s not just salmon, it’s not just anchovies,” says Crona.
Journal reference: Nature Communications, DOI: 10.1038/s41467-021-25516-4
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