Leveraging aquaculture to improve nutrition with reduced environmental impacts

Harvesting fish in Dinajpur, Bangladesh. Photo by Finn Thilsted, 2012.

They are usually only a few centimeters long. And they are eaten whole, with bones and organs included. They are collectively termed “Small indigenous species” – and refer to several species of different small-sized (<25 cm) wild finfish that are part of local diets in Bangladesh. These fish have traditionally been caught, but also make their way into household ponds and commercial production systems where they can proliferate on feed inputs. Previous studies have noted their remarkable nutritional densities and have called for a greater consumption of them to stave many of the micronutrient deficiencies that still plaque many of the Bangladeshi people.

The aquaculture production boom over the last few decades has reduced fish prices and enabled more of the poor to consume these nutrient-rich food sources. But the abundance of the small indigenous species in many of the aquaculture systems in Bangladesh is still scarce. Therefore, in spite of consuming more fish on average, the transition from consuming predominately wild capture fish, to even shares of farmed and wild fish, has meant that the supply of some micronutrients has remained unchanged or even decreased1.

In our study we confronted the question of how to boost the nutritional supply of existing aquaculture systems with the least environmental burdens, what we refer to as ‘nutrition-sensitive aquaculture’. By coalescing nutritional and Life Cycle Assessment data of aquaculture production, we were able to conclude that only an increase in the relative share of these small indigenous species compared to the other species grown in the pond can raise average micronutrient densities produced to the level of average wild fish. In addition, by focusing on various environmental metrics, we determined that systems that co-produce rice and fish can meet the above nutritional requirements with the least environmental impacts.

While these recommendations may appear simple, scaling up production and nudging consumers to more regular consumption of small indigenous species remain important hurdles for implementing these changes. Technological innovations could solve the prior, while the latter require shifts in policy and consumers’ perceptions. As diets shift according to trends and income, traditional foods are sometime perceived as old fashioned, especially among the young. Policies and programs that reconnect people to traditional food sources such as small indigenous species can therefore also reap a cultural benefit.

Although our analysis focused on Bangladesh, the approach we outlined in our study can and should be used in other settings in order to design food systems that simultaneously improve environmental and nutrition outcomes.

  1. Bogard, J. R. et al. Higher fish but lower micronutrient intakes: Temporal changes in fish consumption from capture fisheries and aquaculture in Bangladesh. PLoS One (2017). doi:10.1371/journal.pone.0175098

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