Unforeseen consequences: Pollinator decline linked to global malnutrition

In the last 60 years, nearly 60% of honeybee colonies in the US have disappeared1. It’s hard to browse the news these days without coming across an article about the perils of global pollinator decline. What’s the big deal?

A recent study in the Proceedings of the Royal Society B indicates that pollinators may have a much more important role than they are usually given credit for. Many countries already struggling with malnutrition will bear the most burden of the pollinator crisis.


A bee pollinating a pumpkin blossom. Pumpkins are an important source of vitamin A and iron in many regions. “My favourite color is…” by Bill Harrison is attributed under  CC 2.0.

Rebecca Chaplin-Kramer of Stanford and her colleagues looked at the distribution of pollinator-dependent plants across the world. They found that crops that are rich in nutrients such as vitamin A and iron are disproportionately reliant on pollinators for food production. In addition, several food insecure regions have many crops that require pollinators.1 “This means pollinator declines could hit hardest on the very people who can afford to lose the least in terms of nutrition,” says Chaplin-Kramer.2

Pollinators are incredibly important for the global food supply. 75% of crop species rely on pollinators, and they are responsible for about 10% of food production worldwide. However, pollinator-reliant crops are not evenly distributed throughout the world, and some areas rely on pollinators for as much as 35% of their food supply.1

The numbers above only represent the amount of food produced; they do not take into account the nutritional value of that food. When Chaplin-Kramer and her colleagues looked at nutrient production from pollinators, they found that pollinators are responsible for nearly 50% of the vitamin A production in Thailand, Romania, parts of India, Iran, Mexico, and many other countries. 1

The worldwide food supply is heavily dependent on pollination from a single species of European honeybee. In recent years, populations of these bees have been declining. Scientists are still not sure what is causing the collapse of these colonies, but parasites, land use changes, and of lack biodiversity have been proposed as possibilities.

Unfortunately, many pollinator-dependent regions already have high levels of malnutrition. Regions that are highly dependent on pollinators are nearly three times as likely to be deficient in vitamin A, which can cause blindness and increase childhood mortality. 1 Similarly, if a region relies on pollinators for 15% of iron production, pregnant women in the region are already three times more likely to be iron deficient. These regions will not fare well if pollinator decline continues at current rates.

Some try to downplay the dangers of pollinator decline. After all, the nine crops that account for half of the world’s food supply self-pollinate or are pollinated by wind. However, a 2015 study in the Lancet by Matthew Smith of the Harvard Medical School found that pollinator collapse could increase vitamin A deficiencies in over 2 billion people. 3 That’s nearly 1 in every 3 people worldwide!

What can be done to ensure pollinator-dependent regions will still have the nutrients they need? Chaplin-Kramer suggests substituting pollinator-dependent crops for crops that do not require pollinators for propagation. 1 For example, pollinator-independent sweet potatoes would be a culturally acceptable substitution for pumpkins because they have similar flavor and nutritional content. These substitutions will not eliminate the need for pollinators, as not all foods have a close substitute, but simple changes could reduce the vulnerability of these regions.

There cannot be one approach to fix all pollinator decline and malnutrition problems. The issues and species involved vary vastly by region, and regions that are more heavily dependent on pollinators should be prioritized for pollinator conservation. This research provides a framework for future conservation efforts to preserve the most ecosystem functions and maximize global health.

Works Cited:

1 Chaplin-Kramer R, Dombeck E, Gerber J, Knuth KA, Mueller ND, Mueller M, Ziv G, Klein A-M. “Global malnutrition overlaps with pollinator-dependent micronutrient production.” 2014. Proc. R. Soc. B 281: 20141799.

2 Rauer, Liz. “New Research Links Malnutrition and Pollination.” Stanford Woods Institute for the Environment, 17 Sept. 2014. Web. 13 Sept. 2015.

3 Smith, M., Singh, G., Mozaffarian, D., Myers, S. “Effects of decreases of animal pollinators on human nutrition and global health: a modelling analysis.” 2015. The Lancet.

This entry was posted in Conservation Biology Posts, Conservation Editorials 2015. Bookmark the permalink.

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