More than 10 per cent of the world's population could face malnutrition within the next few decades due to falling fish catches, warns a new study.
The study, conducted by scientists at the University of British Columbia and Harvard and published Wednesday in Nature, combines data on fish populations and nutritional needs around the world. The results set off alarm bells about the continued effect that overfishing and climate change could have on human health – especially in developing countries where people are most reliant on fish for nutritional needs.
"It's not just a biodiversity issue; it's not just an economics issue," said the report's lead author, Christopher Golden, a researcher at Harvard. "We need to be really thinking through this third dimension, human health and well-being."
The research relies on data from UBC, which show that global fish catches have declined yearly by 1.2 million tonnes since 1996. According to the study, this is due in large part to "destructive fishing practices, industrial population, climate change and coastal development for urbanization and aquaculture."
If current trends persist, 845 million people – about 11 per cent of the world's population – could be facing deficiencies in zinc, iron or vitamin A by the year 2050, the study says. The study further estimates that for 19 per cent of the global population, up to one-fifth of their intake of certain essential nutrients, such as omega-3 fatty acids, comes from fish.
Developing countries in low-latitude areas – such as sub-Saharan Africa and southeast Asia – are especially vulnerable due to their reliance on fish for nutrition. This problem is further exacerbated because the same areas are at higher risk for illegal fishing, weak governance over fisheries and population pressures, according to the researchers.
Meanwhile, countries such as Canada play a significant role, said William Cheung, a professor at UBC's Institute for the Oceans and Fisheries and one of the researchers on the study.
"While the developing countries are nutritionally vulnerable, they are actually exporting fish to developed countries for their consumption," Mr. Cheung said.
"So for countries like Canada, we have to be conscious about the fish we are consuming, where it's from and how it may link to impacts on fish stocks and other countries."
Mr. Cheung said that whenever possible, consumers should ask questions about where their seafood is from and try to purchase from sustainable options – either from local sources or certified sustainable fisheries.
According to Mr. Cheung, previous studies of this nature have focused on how falling fish stocks have affected the availability of animal protein. But, he said, the micronutrients focused on in this study, such as omega-3 fatty acids, are much more difficult to substitute and strongly dependent on animals.
Deficiencies in these micronutrients have been linked to maternal mortality, child mortality and reduced immune functions, he said.
Meanwhile, farmed fish – at least at current levels – is not enough to counteract the trend, according to the study. This is in large part because much of that product, too, is going to developed countries.
"Where aquaculture is growing, much of it is aimed at wealthier consumers in domestic cities or in international markets, rather than rural local areas," the study said.