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MARINE VISUAL ECOLOGY RESEARCH A number of scientists have noted that many deep-sea benthic animals have very large eyes, but the sensitivity of these eyes, or what they could possibly be using them for, has remained a mystery. In the pelagic zone (pelagic means in the water column; benthic mean on the ground), animal eyes do increase in size to a certain 
depth, but then, as the downwelling light becomes too dim even for their eyes, their eyes get smaller and smaller.
After all, why waste energy on eyes if there's no longer any light to see by? The mystery is that at these
same depths where pelagic species have tiny eyes, benthic species have very large eyes.
Light from the sun is not the only source of light in the sea. There's another very common source of light, and that's bioluminescence, which is light made by plants or animals. For most people, the most familiar animals that are bioluminescent are fireflies. Bioluminescence is much more prevalent in the oceans than it is on land, and it's been estimated that 90% of the animals living below 500 m in the pelagic zone are bioluminescent, these animals include fish, squid, shrimp and jellyfish. Since there is no visible light remaining from the surface, the huge eyes of these deep-sea species must be adapted for viewing bioluminescence. This is a great hypothesis, but very little is known about bioluminescence on the deep-sea floor, and nothing is known about the visual systems of the deep-sea inhabitants. VISION The visual systems is these deep-sea species have never been studied because it's been impossible to bring up benthic species that haven't been blinded by the light. Their eyes are so sensitive to light that exposure to 
surface light levels permanently blinds them. Even the bright lights of the ship would do permanent damage.
Therefore, standard commercial traps and trawls can't be used to collect these animals. Rather, special benthic
traps designed by engineers at Harbor Branch are being used for collections.
Another reason why so little is known about the visual physiology of deep-sea species is that they rarely survive more than a week after being brought to the surface, and therefore would not survive transport back to a land-based lab. Dr. Tamara Frank, from the HARBOR BRANCH Visual Ecology Department, will be using a special system designed for electrophysiological recordings on shipboard to study these animals as soon as they're brought to the surface. BIOLUMINESCENCE To explore for new sources of bioluminescence in the benthic environment, Dr. Edie Widder, from the HARBOR BRANCH Bioluminescene Department, will be using an underwater ISIT (Intensified Silicon Intenstified Target) video camera mounted on the JSL. The team will also be using a UV light to  look for fluorescence, which is sometimes (but not always) an indicator of
bioluminescence. Any new sources of bioluminescence will be collected for shipboard studies such as
measurements of emission spectra (the color of the light).
Additionally, a new tool for ocean exploration called Eye-in-the-Sea will be deployed for the first time. This deep-sea camera system, developed by Dr. Widder, can be left on the bottom to record behaviors when there is no noisy submersible with bright lights in the vicinity to scare the animals away. It uses an especially sensitive camera (an I2CCD) that can record bioluminescence and it is hooked into a light sensor that turns the camera on in response to a bioluminescent flash. After the camera comes on and records some of the bioluminescence, a red light turns on revealing the animal. Based on Dr. Frank's recordings from the eyes of deep-sea animals, we believe this light should be invisible to the animals. It is hoped that Eye-in-the-Sea will reveal behaviors and possibly even animals that no one has ever seen before. • HBOI MARINE SCIENCE - VISUAL ECOLOGY DEPT. • 'Virtical Migration - The Ups and Downs of Sea Life' - July 1999 [ VIDEO FOOTAGE - QUICKTIME REQUIRED ] 
Johnson-Sea-Link - Benthic shark and shrimp footage
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