Exploring Deep Bahamas Reefs with New Eyes


After two highly successful missions exploring deepwater habitats unique to the Gulf of Mexico, the international Deep Scope team is going tropical. From August 17th to the 28th, the researchers will focus their studies on remote deepwater cliffs in the Bahamas. The overarching goals of this third expedition will be to use an advanced array of tools such as the Eye-in-the-Sea stealth camera system to see the deep-sea like never before and to continue experiments aimed at revealing what deep-sea animals can themselves see.

Deep Scope will take place aboard Harbor Branch's Seward Johnson research vessel and the Johnson-Sea-Link II (JSLII) submersible. The expedition will include researchers from Harbor Branch; Duke University; the University of Queensland, Australia; the Ocean Research and Conservation Association in Ft. Pierce, and the University of Texas at Austin. BBC and NOVA Science documentary crews, one journalist, and one teacher will also be on board to chronicle the expedition.

The National Oceanic and Atmospheric Administration's (NOAA) Office of Ocean Exploration, which was created to investigate the oceans for the purpose of discovery and the advancement of knowledge, is funding the expedition. NOAA is an agency of the U.S. Department of Commerce.

Research Sites

Most of the research will focus on the bases of deep-sea cliffs, which are the home of myriad reef animals and are also favored cruising grounds for large predators such as sharks. The team has identified several promising locations for submersible dives, including cliffs near Chub Cay, Gouldings Cay, San Salvador and Eleuthra, but which sites they actually study will depend on the weather. The goal will be to explore areas protected against the winds on a given day by nearby islands.

Stealth Camera

As on previous Deep Scope missions, the group will be using the Eye-in-the-Sea to unobtrusively observe deep-sea life. This unique camera system will be deployed on the seafloor using the submersible and left for 24-hour or longer intervals to record video using very low levels of infrared light that deep-sea animals cannot see. This will allow the camera to capture natural behaviors and quite possibly footage of animals that have evaded scientists using other tools. Twice now the system has captured footage of a previously unknown squid species roughly six feet long, among other examples of bizarre and mysterious deep-sea life, and there is no telling what creature await the team in the Bahamas.

Fluorescence (or, the Psychedelic Sea)

Researchers will also use special light and filter systems to spot animals that are fluorescent. Fluorescence occurs when something absorbs light of one color and then reemits light of, or glows, another color, a phenomenon some might be familiar with from blacklight posters. In the ocean, detecting fluorescence can allow scientists to spot animals that would otherwise be too effectively camouflaged to see. Fluorescence is also important because the proteins that allow animals to fluoresce are used in genetic research and new fluorescent animals may contain proteins that offer novel benefits in such work. Perhaps most intriguing, though, past research has given tantalizing signs that animals in the surface waters may in some way be able to use fluorescence for communication, a concept the group will be exploring in detail.

Ultraviolet and Polarized Light

The scientists will collect deep-sea animals using specially designed traps that will enable them to collect these animals without exposing them to submersible lights. On a previous expedition, a deep-sea crab was collected that could see ultra-violet light, and scientists are hoping to collect more of these species, as well as samples of the corals that they live on, for further studies. As these animals live too deep for UV light from the sun to reach them, there may be an undiscovered source of UV bioluminescence in the deep-sea. Animals closer to the surface will also be collected, to continue exploring the possibility that some open ocean animals can detect polarized light. This would allow them to spot otherwise "invisible" transparent prey, solving one of the mysteries of how open water food webs work

Seeing What They See

Another goal for the team will be to continue work to recreate, as close as possible, what the deep-sea looks like to deep-sea animals. This will involve using data from this and previous expeditions on the eyes of deep-sea organisms to determine what range of light they can detect as well as measurements of light levels in the deep. Armed with this information the team will be filtering the submersible's lights during certain dives to recreate that same kind of view, providing a "crab-eye view" of the deep-sea's alien terrain, which will be captured on video and in photos.

To follow along on the expedition, visit @Sea regularly for dispatches describing each day's most exciting discoveries and accomplishments.

© 2007, Harbor Branch Oceanographic Institute