Researchers lay cable at Blue Lake Reservoir in Oregon's Cascades for an experiment measuring relative humidity during an OSU-led summer workshop. (Photo: Lina DiGregorio)

High-tech science got a lift last summer from a curiously low-tech device: a potato launcher.

Puzzling over the best way to string fiberoptic cable through dense, old-growth canopy, OSU scientists devised a “canon” with an air-compression gun and fishing line weighted by a starchy tuber. From a 100-foot research tower in Oregon’s H.J. Andrews Experimental Forest, a research assistant spent an afternoon in June launching lengths of Swiss-made cable through towering boughs of Douglas fir and big-leaf maple.

“We needed a projectile with a mass sufficient to place the line, something that would not be hazardous and would not light the forest on fire,” explains OSU researcher John Selker. “We tried everything – bows and arrows, slingshots. In the end, we were shooting organic, biodegradable potatoes around the forest.”

Transformative Science

Selker, a professor in the Department of Biological and Ecological Engineering, is taking ecosystem sensing to new heights with an advanced generation of high-tech cable. Today’s fiberoptics use glass strands so pure that pulses of light zip along the line with little resistance. By detecting the tiny amount of light that scatters back from the source, scientists can measure the temperature of the glass. What that means for monitoring the infinite complexities of ecosystems such as watersheds and ancient forests is an exponential increase in precision, down to hundredths of a degree. Scientists can now take measurements more frequently (every three seconds) at closer increments (every meter) across longer distances (up to five or six miles), capturing spatial structure in three dimensions. The result is an infinitely more nuanced – and thus more accurate – depiction of the natural world.

“With fiberoptics, we’re getting about 10,000 times more data than we did with traditional sensors,” says Selker, a hydrologist who studies stream dynamics. “We’ve added a whole bunch of zeroes to the precision of our measurements. This is transformative science. It’s changing how we see the world.”

Getting finer data about the temperature, relative humidity and evaporation of a stream will vastly improve resource management, Selker predicts. Indeed, warming is one of the greatest dangers threatening watersheds. That’s because fish thrive in narrow spectra of water temperature. A few degrees warmer can mean less oxygen, more pathogens and greater stress on aquatic animals. Strategies for stream protection and restoration can be more effective if based on truer readings and better models.

But for its promise to be fully realized, the novel technology needs rigorous field testing. “There are a whole lot of practical problems to be overcome,” Selker says. The sensors need to be carefully calibrated, for example, to correct for things like weld joints in the wires, “jitter” caused by stream flow and albedo (light reflection). “The history of science is littered with great measurement techniques that fizzled because of poorly run experiments,” says Selker. “We need to seed the science community with people who know how to do this.”

So Selker, along with colleagues at the University of Nevada, the Delft University of Technology in the Netherlands and the U.S. Geological Survey recently led two international workshops to test and troubleshoot fiberoptics and sensing instruments in real-life settings. The National Science Foundation’s Consortium of Universities for the Advancement of Hydrologic Science funded the sessions, which were part training, part joint problem-solving – what Selker calls “proof of concept” studies.