‘Don't sacrifice nutrition for yield’ warn scientists

The move comes after researchers analysing fish consumption and nutrient intakes in Bangladesh households found that although consumption increased by 30 per cent from 1991–2010 (with a 33 per cent decline in the consumption of non-farmed fish species compensated - in terms of quantity - by large increases in consumption of farmed species), there were significant decreases in iron and calcium intakes and no significant change in intakes of zinc, vitamin A and vitamin B12. The researchers, led by Jessica R Bogard from the University of Queensland in Australia, said this reflected the lower overall nutritional quality of fish available for consumption over time.

“Our results challenge the conventional narrative that increases in food supply lead to improvements in diet and nutrition,” the scientists noted. “As aquaculture becomes an increasingly important food source, it must embrace a nutrition-sensitive approach, moving beyond maximising productivity to also consider nutritional quality. Doing so will optimise the complementary role that aquaculture and capture fisheries play in improving nutrition and health.”

The study, titled Higher Fish But Lower Micronutrient Intakes: Temporal Changes In Fish Consumption From Capture Fisheries And Aquaculture In Bangladesh, was published this week in the research journal Plos One.

Undervalued source of micronutrients

The scientists noted: “Malnutrition is one of the biggest challenges of the 21st century, with one in three people in the world malnourished, combined with poor diets being the leading cause of the global burden of disease. Fish is an under-recognised and undervalued source of micronutrients, which could play a more significant role in addressing this global challenge. With rising pressures on capture fisheries, demand is increasingly being met from aquaculture. However, aquaculture systems are designed to maximise productivity, with little consideration for nutritional quality of fish produced. A global shift away from diverse capture species towards consumption of few farmed species has implications for diet quality that are yet to be fully explored.

“The valuable role of aquaculture in Bangladesh [the world’s sixth largest producer of aquaculture products] in securing the availability and affordability of fish is unquestionable. If growth in this sector had not occurred, declines in nutrient intakes described [in the report] would undoubtedly be much more severe, with far more serious implications for nutrition and health.

“However, the results [of the study] highlight unintended negative consequences of policy decisions and agricultural investments which are narrowly focused on maximising production and productivity. In doing so, our results challenge the dominant rhetoric that increases in food supply automatically lead to improvements in diet and nutrition.

“These findings are of significance to many countries experiencing rapid growth in aquaculture alongside declining quantity and diversity of species from capture fisheries. In this light, whilst the findings are specific to Bangladesh, it is possible that this decline of nutritional quality linked to a shift towards greater farmed fish consumption, is occurring on a global scale. As aquaculture becomes an increasingly important food source for many, it must embrace a nutrition-sensitive approach, by considering how changes in food supply affect nutritional quality of diets.”

The report can be read in full here.