/ 6 July 2016

Plummeting fish stocks will cause a health crisis — but this need not be the future

Fish stock is on a sharp decline
Fish stock is on a sharp decline

The world has to solve an impossible conundrum: the amount of fish coming out of the ocean peaked in 1996, yet the world’s population will grow to a peak of 10-billion by 2050. About half of that population will live near the Equator and will rely on fish. But, largely as a result of illegal fishing and overfishing, the food source will have plunged.

That means 845-million people will be denied this protein source and critical micronutrients, according to a report, Fall in Fish Catch Threatens Human Health, in the peer-reviewed journal Nature

Previous research into the fall in fish stocks has looked at what happens when people lose their primary source of proteins. 

The new research, from the Harvard Chan School of Public Health in the United States, instead looked at the other nutrients that come with fish. In countries along the Equator people get their zinc, iron, vitamins and omega-3 fatty acids from fish. Iron brings oxygen into red blood cells and helps prevent anaemia in children. Fatty acids help the brain develop. 

An inadequate supply of micronutrients leads to child and maternal mortality, reduced immune system functioning, growth retardation and negative cognitive effects, according to the World Health Organisation (WHO). 

Writing in Nature, lead author Christopher Golden said: “We predict that more than 10% of the global population could face micronutrient and fatty-acid deficiencies.” This represents a “perfect storm” for countries that rely on fish caught at sea for nutrition, he said. 

In Africa, Angola, Ghana and Nigeria are the most vulnerable to decreasing fish stocks.

Climate change will exacerbate the problem, according to the Harvard research. Floods and droughts are happening more often in this region. This is destroying crops on land, leaving the ocean as the last source of staple food. In these cases, the team said: “Fishing for food has become an act of desperation.”

It’s been suggested that aquaculture can be the solution for declining fish stocks. On an industrial scale, it would allow natural fish stocks to recover. But, said the researchers, developing countries do not have the resources to do this. They also found that farmed seafood ends up being sold in Europe and North America. 

In that part of the world, moving away from fish (and meat) is a decision that people can willingly take because they can afford supplements and to vary their diet. 

The Harvard team said people in the developing world — where fish and meat are increasingly unavailable — do not have this option. On top of that, people in those countries face more diseases and need a healthier diet to survive. In other words, those who need the nutrients the most are those who cannot afford them. 

The effects of this are well documented by WHO and the Food and Agriculture Organisation. A fifth of pregnant women have iron-deficient anaemia and a third are vitamin-A deficient. The organisations say these children will start life on the back foot, having not grown to full physical and mental size in the womb.

Golden said countries had to take the problem of declining fish stocks far more seriously. Where there is a focus on fisheries, it is on the potential loss to biodiversity and income, but “there should be a much stronger emphasis on human health”. That would allow for the creation of policies that had changed agriculture to a point where there is enough food to feed the world’s population. 

Having looked at 5000 fisheries, Golden’s team said that just by managing things better, fish catches could increase by 10%.