Nature's Stylus

Meet the diatom: a tiny ocean plant with a knack for drawing. Scientists have big ideas for these little algae--but first they have to figure them out.

To the beachcombing tourists of Seaside, Oregon, the dark, brownish foam that washed up on the peaceful resort town’s shores one day in February looked like an oil slick. Up and down the beach, swaths of coffee-colored froth bubbled in with the surf, settling in unsightly clumps on the sand. Worried visitors poured into boardwalk shops, asking if there had been a ship wreck off shore. The tourism office got so many calls that it issued a press release. No need to panic, the release soothed. It’s just diatoms. Billions and billions of diatoms.

Diatoms—microscopic, single-celled algae that grow in virtually every body of water on the planet—have been likened to the grass of the ocean because they are so plentiful and so humble a part of the ocean food chain. They bloom in huge numbers near the ocean surface, where they take in energy from the sun, along with nutrients in the water, and convert them into carbohydrates. Fish feast on them—the nutritionally valuable omega-3 fatty acids in seafood come from the diatoms they eat.

Diatoms are also unheralded players in the Earth’s carbon cycle: They remove the same amount of carbon dioxide from the atmosphere each year as all the world’s rainforests combined. Yet they do all this with very little fanfare. In fact, most people never hear of them, except on the rare occasion when winds push blooms of diatoms onto a seashore, as happened in Seaside. And even then, they appear en masse, as an oily muck that conceals their amazing beauty.

Up close, diatoms are actually quite stunning. They are encased in cell walls made of silica, a kind of glass, and each of the thousands of species of diatom features a unique pattern of intricate grooves, lines and notches. When they were first discovered shortly after the invention of the microscope, parties were convened just to marvel at their filigreed, jewel-like shapes.

But with that beauty also comes intriguing possibilities. Using the high-tech tools of biotechnology, scientists are starting to learn how diatoms do the things they do, including their remarkable ability to create their intricate cell walls using tiny lines of silica. The answers could help advance a field of human endeavor that is critical to modern life as we know it.

“Diatoms are beautiful organisms that are able to lay down nanometer-sized lines of silica,” says CALS molecular biologist Michael Sussman. “If we could genetically control that process, we would have it nailed. We would have a whole new way to make computer chips.”

These kinds of intuitive leaps are entirely in character for Sussman, whose interest in diatoms was sparked by a single, one-hour talk he attended at a genomics conference organized by the J. Craig Venter Institute. Born and raised in New York City, Sussman brings a free-associating spirit to his laboratory, which is filled with equal parts laughter and inspiration. “Things are usually pretty mirthful [around the lab],” says Matthew Robison, one of Sussman’s graduate students who worked with him researching diatom genetics. “Sometimes it can be difficult to keep him on topic, but we try our best.”