Will Ambrose, assistant professor of biology specializing in Arctic sea-floor ecology, recently took Peter Tilney '99 and Melissa Grable '99 on a month-long senior-thesis research project aboard the U.S. Coast Guard cutter Polar Sea in the ice-covered Chukchi Sea, northeast of Alaska.

Ambrose, Grable, Tilney and two other researchers studied the diversity of single-cell ice algae, the distribution of ice algae in ice-core samples and whether sea floor-based organisms consume ice algae.

"The perception has been that when you take a system and cover it with ice, light doesn't get through," Ambrose said. "It's cold and dark, and there isn't much plant life fueled by this." The researchers found just the opposite: under more than six feet of ice at depths of 100 feet, the Chukchi sea floor is rife with sand dollars, brittle stars and star fish — and more than 260 species of ice algae to eat.

As guest freight aboard a vessel with other duties, the group collected data in 30-hour stretches to make the most of their limited time. Numerous polar bears required that they have an armed Coast Guard escort when venturing on the ice to gather core samples and shoot underwater video through a remotely operated vehicle — what Tilney described as a "multimillion dollar submarine Nintendo game."

With his former students as co-authors, Ambrose is preparing several articles for publication, including one based on Tilney's senior thesis