What a Thorny Devil and Camel Nose Can Teach Us About Water

Within our bodies and our societies we use water as a solvent, transporter, heat conductor, coolant, buffer, lubricant and structural component. Adapting to a new conservation-based prosperity will mean figuring out ways to make water work more efficiently.

Adapting is something that nature does very well, and because organisms have occurred in water for billions of years, there are many examples of clever tactics. Here are some:

Doing without: When it comes to cost cutting, the most effective way to save material is to not use it at all. Tardigrades, or water bears, are the supreme champions at doing without. These common, 1-milimeter long invertebrates have developed a way to survive virtually without water by a process called cryptobiosis.

In one type, the water content of their bodies decreases to less than 1 percent and their metabolism rate becomes undetectable. They are thus able to withstand extreme cold, heat and radiation and still survive for a decade or more in this suspended state.

One reason is that they possess a special type of sugar, trehalose, within their cells that, instead of crystallizing during desiccation, becomes a gel. This gel keeps the cell walls and organelles from being damaged until water returns. Researchers in the field of cryobiology are now investigating this ability in order to preserve medical vaccines, food, sperm, blood or even organisms. 

Collecting: There seem to be as many ways of collecting water in nature as there are organisms on the planet. As water becomes scarcer we may want to learn some of these micro-harvesting techniques. The marsh crab (right) is a crustacean with very hairy legs that serve a purpose. The tiny setae are hydrophilic and therefore suck water out of the interstices of the mud that the crab lives in so the animal can drink it.

The Namibian Desert beetle captures fog by collecting it on hydrophilic bumps and then running it down hydrophobic channels to its waiting mouth. The Thorny Devil of Australia (above) captures dew in a similar fashion but with the tips of its protective scales, grooved to run the liquid to the right place.

Storing: Smarter water systems may require more adaptive storage methods and nature has some lessons to impart. The barrel cactus for instance, uses a pleated design to expand and contract as conditions dictate. The Baobab tree, the world's largest succulent at over 20 meters, is a prodigious collector of water, up to 120,000 liters in some cases, in thin-walled cells within its soft, pithy interior. This plant also expands and contracts with the amount of water available.

Both of these plants also exhibit a common trait in the natural world, multi-tasking. Most plants use water for structural integrity as well as other benefits. “Hydraulic architecture” seems, for now, to be a term limited to botanical parts and diversion ditches, but water has also been used as a structural component in some cofferdams. It possesses qualities of thermal capacity, mass and pressure that could be simultaneously capitalized on.

Transporting: The circulatory systems in plants and animals are wonders of engineering, as is the exchange of water through your skin to cool you through evaporation. Interestingly enough, your sweat ducts are not straight, but helically shaped tubes. One sees the spiral in fluids at all scales, from the drain in your bathtub to spiral nebulae, and this is what inspired Jay Harman to invent his line of highly efficient fluid mixers. Harman is the founder of Pax Scientific, a maker of fans, propellers and impellers, all based on the spiral geometry that he observed in nature.

Reacting: Substituting information for energy or material is a common survival strategy in nature. The tactic of “just-in-time information” is the refinement that makes this work, particularly in the cellular to organism scales.

As just-in-time delivery of parts reduces the need for warehousing in the manufacturing world, just-in-time information, (coupled with on-site manufacture) reduces the need for energy in nature. Your body, for instance, doesn't transmit the information to your brain that you are thirsty until the chemical balance in your fluid systems triggers this response.

Agricultural systems that employ grids of buried sensors operate on a similar principle. Researchers at Iowa State University have developed a grid that can register temperature and moisture content precisely and then beam the information via low-frequency radio waves to a central controller. In future operations, GPS-controlled machinery or a framework of pipes will then be able to deliver water and nutrients to the areas in need when they need it. Coupled with a solar-powered satellite weather station, this type of feedback system will save water, expensive and potentially polluting fertilizer, and money.