Night diving by coral light

Glowing green and swimming off the corner of the picture, the eel looked unnatural, as if it had been Photoshopped with DayGlo colors. “That darn eel,” says David Gruber, led to a weeklong eel-catching expedition near the sandy beaches of Lee Stocking Island in the Bahamas.

Gruber teaches biology and environmental science at Baruch College in Manhattan, but his passion is scuba diving with dinoflagellates, single-celled bioluminescent organisms. His group’s glowing photographs of underwater Caribbean creatures — sea anemones, coral and fishes — illuminate the new Creatures of Light exhibit, a show at the American Museum of Natural History themed around all things bioluminescent (producing their own light) or biofluorescent (absorbing light and reemitting it as a different color).

Vibrant photos of the coral wall give visitors a virtual night dive experience even if they’ve never donned a wetsuit. “When you swim in the water at night, it’s like a disco party,” Gruber says.

Instead of teaching this past semester, Gruber worked on the exhibit, with the help of a National Science Foundation grant. In addition to the glowing photo wall of Little Cayman’s reefs, he worked with museum artists and scientists to perfect the magnified dinoflagellate and jellyfish models. Gruber, who trained as a journalist and has a reporter’s passion for accuracy, even brought in a spectrometer to ensure the light in the exhibit matched nature’s luminescent wavelengths.

Live flashlight fish, filled with bioluminescent bacteria, contribute to the exhibit as well, blinking what looks like a secret code to passers-by. “They’re so stressed out right now,” Gruber says, looking concerned as he leans closer to their tank. “It’s a really energetic process to glow.”

It takes energy to pursue glowing coral and fish, too — and to discover new eels. When Gruber saw his colleague Jim Hellemn’s photo of the green serpent, he thought Hellman was playing a practical joke. Skepticism turned to enthusiasm when the researchers realized the eel was a previously unknown fish living in a biofluorescent reef. “From that point we wanted to get this eel,” Gruber says.

His diving group flew to the Bahamas, zipped on their wetsuits and spent hours catching and cataloging fish. They gave most of the specimens to the museum, but Gruber kept the eel, storing it in a freezer at his Gramercy lab. He is purifying its fluorescent proteins and hopes they can someday be used as luminescent tags in biomedical research.

At 39, Gruber is a real up and coming guy, says Vincent Pieribone, a neurobiologist at Yale University School of Medicine. “He’s a practicing scientist, but he’s got a knack for the communicating aspect, which is rare in our field.”

Pieribone would know. They spent two years writing a book about biofluorescence and bioluminescence called “Aglow in the Dark,” shortly before the 2008 Nobel Prize in Chemistry was awarded to three scientists who advanced fluorescent protein research.

Gruber and Pieribone, who met through Pieribone’s girlfriend, now wife, once spent an entire month together in Australia collecting fluorescent creatures in 2002. “We’ve been having a bromance for years,” Pieribone says.

Gruber’s love of the water began as a child in New Jersey. During family vacations, he learned how to boogie board in the waters of Malibu, California. At the University of Rhode Island, he surfed with friends before morning oceanography classes.

He found his calling in Belize, studying reef fish during his junior year. He spent hours every day catching fish, suturing glow sticks to their bodies and tracking their movements in the reef at night.

“You start to see there’s a community down there,” he says. “You come across the same fish every day and you know which rock he’s under. You know where the eel is, where the octopus is.”

Following graduation, Gruber worked as a bicycle messenger in Washington, D.C. until he landed an internship with the Smithsonian Institution and flew to Guyana in South America to research forest diversity. Most days, he climbed trees and fended off mosquitoes.

But trees aren’t underwater, so he left the Smithsonian for Duke University, where he studied climate change’s effects on the oceans, a factor in the death of coral colonies. Then he worked for the South Florida Water Management District, measuring the water quality and sea grass in Florida Bay. The project was constantly in the press. Inspired by investigative reporter and novelist Carl Hiaasen’s stories about swamp destruction, Gruber offered to share a firsthand account about the restoration effort.

But “nobody would publish my work because they said I wasn’t a journalist,” he says. “So I applied to journalism school.” One of his journalism professors at Columbia, Sig Gissler, remembers Gruber as earnest, engaging and energetic. “We called him a man of science with a soul of a reporter because while he didn’t have a lot of experience — he was total rookie — he made up for it with tenacity.”

The tug of the water pulled him back to research, and Gruber powered through the next six years, earning his doctorate in biological oceanography at Rutgers University. Few scientists knew the complete history of fluorescent protein research, so he and Pieribone wrote a book about how the bioluminescent jellyfish changed the face of modern biological science. “It was just a really nice narrative,” Gruber says, “but it was a difficult narrative because your main character is a protein.”

Undeterred, they traveled across the U.S., Australia and Russia to interview the researchers whose work led to the famous green fluorescent protein that would win the Nobel. Some sources were reserved so Pieribone, a neurobiologist, let Gruber take the lead. “He was more subtle,” Pieribone says. “He was more of a journalist. I have a huge respect for those skills.”

The duo published their book with Harvard University Press in 2005 as Gruber moved to Brown University for post-doctoral study on ways to use fluorescent proteins as biological sensors. Researchers can introduce these glowing proteins into cells to track all kinds of activity, including the growth of tumors or chatter between nerve cells.

“Very little is known about how widespread of a phenomenon biofluorescence is in nature, even though it has proven to be valuable as a tool for biologists and medical scientists,” says Dan Tchernov, head of marine biology at the University of Haifa. He has co-authored several papers with Gruber, and noted that because researchers lack a remote operated vehicle to study deep reefs, Gruber is building one. “Dave is well regarded and a very promising researcher who can successfully bridge sciences,” he says.

Now at Baruch, Gruber chases an ever-expanding array of projects on the side. “I love studying all life forms and their beautiful interconnections,” he says. Recent projects include a 2010 study about correlations between autism and cancer and a current project on the epigenetics of diabetes. All the while, he’s been collecting fluorescent proteins and co-producing an IMAX film about bioluminescence. He, Pieribone and colleagues have published a cascade of studies about fluorescent proteins, including a 2010 paper describing the world’s brightest — a glowing green protein from a warm water coral.

Pieribone praises his friend’s creativity, but says it impedes Gruber’s career. “He doesn’t stress the things in an academic career that will make him a full professor at Harvard,” Pieribone says. “You have to be really focused and Dave just doesn’t want to focus that heavily on one thing.

“He’s like the indie film director,” Pieribone says. “He’s not the one who sells a lot of movie tickets, he’s not the Michael Bay, but he makes the better movie.”