No one has ever seen a living giant squid, according to Edith Widder, a senior scientist at the Harbor Branch Oceanographic Institution in Fort Pierce, Fla. The only way anyone knows these animals exist is that their bodies float when they die.

Widder is an expert in bioluminescence—visible light made by living creatures—and has set out to photograph it. For a fairly common marine phenomenon, bioluminescence has been maddeningly elusive to photographers.

Widder believes a technique that can successfully photograph marine bioluminescence could be the key to studying the giant squid and, perhaps, vast ocean populations that have yet to be discovered.

Scientists estimate that roughly 90 percent of the organisms— fish, squid, shrimp, and jellyfish—living beyond the reaches of visible light at depths of 200 to 1,000 meters are bioluminescent. So far, efforts to study these animals have been thwarted because traditional methods are intrusive. Submersibles and remotely operated vehicles are noisy and light up the ocean, scaring away sea animals before they can be photographed.

Widder has designed a stealth camera, called Eye in the Sea, which can be placed on the ocean floor to capture images of undersea creatures undisturbed in their dark habitats. She has deployed the camera twice since July to test its seaworthiness and work out its kinks. She thinks it could be a breakthrough in ocean exploration.

A tripod holds the camera, illumination source, and battery pack. The camera is an off-the-shelf surveillance model, sealed inside an anodized aluminum container. The camera setup includes a PC stack to digitally record images and a sensitive light detector known as a photomultiplier tube. A red light, invisible to marine life, sits atop the camera assembly.

A robotic arm attached to a submersible or remotely operated vehicle places the tripod at a selected location on the sea floor. When a bioluminescent sea animal passes within range of the photomultiplier tube, the sensor triggers the camera. The camera begins to record the bioluminescence and the red light turns on, revealing the animal. The camera records black-and-white images digitally at a rate of 20 frames per second.

The Eye in the Sea, being launched with the submersible Johnson Sea-Link during a trial, may photograph creatures of the very deep unobtrusively.

After 24 or 48 hours, the submersible returns. A pinger attached to the system ensures that the vehicle can find the tripod for retrieval. The system is then brought to the surface.

The Eye in the Sea set out on its maiden voyage on July 23, in the Monterey Canyon off Monterey Bay in California. It traveled to the site on the Point Lobos, a research vessel of the Monterey Bay Aquarium Research Institute, and went to the floor of the canyon with the ROV Ventana.

A second deployment, using the Johnson Sea-Link, a submersible operated by Harbor Branch, took place in August off the coast of Charleston, S.C. A third test was scheduled to put the camera back in Monterey Canyon last month.

"The beauty of the submersible or ROV is that you can set it down looking at something cool," Widder said. The Eye of the Sea can withstand depths of 3,000 feet, the same pressure rating as the Johnson Sea-Link.

Widder was confronted by the mechanical difficulties of deep-sea exploration right off, when a seal on the camera's container failed during its first launch, damaging the power supply. She repaired the power supply and also replaced circuit boards on the PC.

The seals must be able to withstand pressures of up to 1,475 psi. The aluminum pressure vessel had to be machined to a tolerance of 5 thousandths of an inch, making allowance for anodization, which added 3 mils to the surfaces, said Jerry Neely, director of engineering at Harbor Branch.

Photos were taken during the second test, off South Carolina, but most didn't come out because of a memory problem in the Windows 98 operating system, said Widder. On the plus side, the few images that came out, although unfocused, showed the creatures were apparently unaware of the red light, she said. The lab is installing Windows 2000 in time for the third trial.

Widder has run the project on a slim budget, helped by funding from Harbor Branch, the Monterey Bay Aquarium Research Institute, and the National Oceanic and Atmospheric Administration and by the sale of her own images of bioluminescence. The Harvey Mudd Engineering Clinic in Claremont, Calif., developed the electronics as a student project. Harbor Branch performed much of the mechanical engineering in-house.

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