The desert beetles revolutionizing our water crisis

Helping tackle water scarcity

For more than 1 in 10 people around the world, access to clean water isn’t a given. The United States Centers for Disease Control and Prevention estimates that 780 million people do not have access to safe drinking water. Industries also suffer from water scarcity — agriculture is both a victim and a cause of water shortages, for example.

As the world’s population grows and demand rises, the need for sustainable sources of water is so dire that some think it will soon cause wars. In the last decade, 466 conflicts around the world involved water, according to the Pacific Institute. And, as the climate warms, the problem will only get worse, the United Nations predicts.

No bigger than an almond, these Namib Desert beetles have evolved in a very special environment, where the only source of water exists in the air.

It’s a place called a “cool coastal desert,” where the cold currents in the water of (in this case) the Atlantic Ocean off the southwestern coast of Africa prevent the air in the area from gathering the necessary moisture for rainfall, meaning that there is very little rain near the coast. Without frequent rain, the wind blows the sand into ginormous dunes that tower sometimes over 1,000 feet tall all along the coast. (One of these dunes in the Namib Desert is even nicknamed “Big Daddy”!) 1

In the morning, as the air right above the ocean cools, fog forms and the wind rolls it across the land. Now, our beetle buds spring into action, collecting water in a process called “fog-basking.” Heading to the top of a sand dune, they orient their bodies just right, let the water collect on their backs, and roll it right into their mouths.

When it comes to fog water collection, the mechanisms at play fall broadly into two parts. The first is “collision and deposition,” which is shaped by the motion of water droplets. The second is “drainage and transport,” which depends on the chemical properties of the water itself.

Can a tiny beetle help with global water shortages? – BBC World Service, 30 Animals podcast

Most researchers have focused on the second part — what to do with the water once it’s been collected. Instead, Fan Kiat Chan, a graduate student at the University of Illinois at Urbana-Champaign team paid attention to the first — collision and deposition.

The experiment was intended to investigate the basic science behind fluid mechanics, Chan said, not as a study designed to solve the problem of water scarcity. But if we can understand why and how animals like the Namib desert beetle collect water, it may allow scientists to create better fog-trapping technology.

In the future, engineers might be able to mimic the dimpled backs of the bugs to make more compact and efficient fog collectors or even portable systems, the researchers suggest.

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