Tropics in a Tank

"Down here it's real foamy," Penn State chemist Robert Minard explains, pointing to a clear, plastic cylinder filled with dingy-white bubbles. "The sea foam rises up and skims over into this bucket." He peers into a bucket, where the end of a long, plastic tube spews dirty froth. "That's sort of organic garbage. You know, it's a sewage treatment plant."

blue, green, and orange fish

This bioactive foam filter, processing hundreds of gallons of water an hour, is only one of many components maintaining the new coral reef aquarium in the HUB-Robeson Center on Penn State's University Park campus. The humid, buzzing room behind the tank is also used to take care of the neigh boring African lake aquarium. Under Minard's guidance, the HUB-Robeson Aquarium Committee and the Marine Science Society campaigned to have the project chosen as the Class of 1999 senior gift. They also helped to design the aquariums and upkeep plans, and constructed the complex physical systems that sustain the tanks.

Although Minard teaches chemistry, he has done a good bit of the engineering work for the reef tank—and there certainly was a lot of it. The small maintenance room is crammed with the support systems. Water constantly cascades from an overflow box in the tank into a smaller, auxiliary tank—called the sump—on the floor. From there, the water runs through the foam filter and is pumped back into the main tank. On its way, the water flows over the top of a refugium, a smaller box inside the sump. The refugium houses several types of aquatic macro algae, spindly looking peppermint shrimp, and a few timid fish that couldn't hold their own against the bullies up in the big tank.

All of these supporting components integrate with the water chiller, the lighting system, and the temperature and chemical monitors, in order to maintain favorable conditions in the tank.

But just what are favorable conditions for a coral reef? "No one really knows—at best we can monitor levels of certain chemicals in the tank, and try to maintain them at natural levels," says Sanjay Joshi, a professor of industrial and manufacturing engineering and long-time marine hobbyist. "There are all these myths floating around, and people try to sell you stuff, but no one really knows. Maintaining a reef tank is still considered an art to a large extent." Joshi believes that a precise chemical and biological balance is necessary in a reef tank for the corals and fish to thrive. "Dipping the tip of your finger into the tank today," Joshi says, "might make a coral die three weeks from now, and you'd never know what happened."

As far as corals go, though, Joshi has the magic touch. He has several reef tanks in his home. Each is brimming over with aquatic life, from branched and brittle orange stalks of coral to red, fuzzy algae that the fish refuse to eat. Joshi's corals grow like weeds, a "problem" that he complains about—and that every other coral hobbyist envies.

Unlike the typical basement hobbyist, though, Joshi is not satisfied with the uncertain art of maintaining a reef tank. Joshi, Minard, and a number of undergraduates here are united in the goal of turning that art into a science. They are aching to know just what is in that foam that comes off the foam filter—a questionthat is right up Minard's alley. He is a specialist in the chemical technique of mass spectrometry, adept at identifying components of complex organic mixtures.

The team also wants to understand how light and tidal action influence the reproductive cycles of the corals. Joshi's previous research on different commercially available lights is a starting point, but the real question is why, in the wild, all corals spawn at the same time, on some moonlit night in autumn. Does the particular light intensity on that one night trigger the spawning? Or does the gentle, constant motion of the ocean waves carry a chemical signal between the corals?

The students are interested in the proper care of a reef tank, and in how other environmental factors—nutrient availability, or pollution, for example—might affect the mix of aquatic life. Students from the Marine Science Society, led by president Casey Mantz, visit the reef tank daily to check the acidity of the water, empty the bucket for the foam filter, and learn how to care for a reef tank in a scientific way. Chemistry majors Marcia Dohne, Nick Hartman, and Erin Shields have begun studying the rise and fall of various chemical levels as the corals establish themselves in the tank. And the more practically minded among them, prompted by Minard and Joshi, would also like to design some new equipment, like underwater cameras to stream continuous video footage to the Web, and better chemical sampling devices to detect minute levels of trace nutrients. The best part about it, though—in the eyes of these enthusiasts—is sharing the results of their research with the community. Students in marine biologist Chuck Fisher's invertebrate zoology course can tromp over to the HUB to see live corals, or download real-time chemical data from the reef tank to analyze. "Less than ten percent of my students have ever been to an ocean in the tropics," says Fisher. "The reef tank provides a great opportunity for them to get some hands-on experience."

Meanwhile, the reef tank is doing great. The live rock shipped in from Fiji is bristly with sprouty plants and googly eyed hermit crabs the size of chickpeas. Ugly sea cucumbers lug themselves around the sandy floor of the tank, sucking in sand with grasping tentacles and venting it out their back ends like miniature snow blowers. Resplendently colored tangs and plump little clown-fish play hide-and-seek in the caverns formed by the rock. Everywhere, fragments cut from Joshi's "weed" collection are blossoming into thriving corals. And all the time, the foam filter bubbles away.

Robert Minard, Ph.D., is senior lecturer in chemistry in the Eberly College of Science, 211D Whitmore Lab, University Park, PA 16802; 814-865-2202; rminard@psu.edu. Sanjay Joshi, Ph.D., is professor of industrial and manufacturing engineering in the College of Engineering, 310 Leonhard Bldg.; 865-2108; sjoshi@psu.edu. The HUB-Robeson aquariums were funded through the Class of 1999 Senior Class Gift. Freelance writer Maureen Gramaglia is an honors student majoring in physics, chemistry, and Russian translation. Photographers Joseph Thren, Shuolung Wu, and Matthew Morey are undergraduates in the Digital Photography Studio.

Last Updated September 01, 2000