Exploring Gulf of Mexico Deep-Sea Habitats


From August 19th to September 3rd, scientists from Harbor Branch and three other institutions will be exploring unique deep-sea landscapes--coral mounds, a canyon and a knoll--in the Gulf of Mexico. Using a variety of advanced photographic and other technologies, the team intends to not only observe the wide range of life forms in the deep in ways never seen before, but also to learn how the animals there see for themselves.

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.

Deep Scope will take place aboard Harbor Branch's Seward Johnson research vessel and the Johnson-Sea-Link I (JSLI) submersible. Besides Harbor Branch scientists, the expedition will include researchers from Duke University; the University of Queensland, Australia; and the Whitney Lab of the University of Florida.

As it did on the first Deep Scope mission in 2004, the group will be using the Eye-in-the-Sea camera system, designed by Edie Widder and colleagues, to unobtrusively observe deep-sea life. Last year the system captured footage of a previously unknown squid species roughly six feet long, and this year the group hopes to make even more exciting finds.

Researchers will also use special light and filter systems to spot animals that are fluorescent, with the goal of understanding how fluorescence may be used in the deep and possibly discovering fluorescent pigments with potential applications for biomedical research. Last year the group discovered the first fluorescent shark, and also inadvertently discovered that methane hydrates, a potential future energy source, are highly fluorescent, a finding that could one day lead to a new means of detecting hydrate deposits.

Most of the research will focus on the seafloor, but during Deep Scope 2 scientists will also use scuba to continue exploring the possibility that some animals living in the open ocean water column can detect polarized light. This would allow them to spot otherwise transparent prey, solving one of the mysteries of how open water food webs work. To expand on work to measure polarized light levels and to determine which animals become more visible with polarized light, expedition co-leader Tammy Frank will also study various open water animals to determine if in fact they do have the power to detect polarization. In addition, the group will be expanding beyond the polarization work to study whether and how animals might use ultra-violet light, which could provide another means for predators to detect otherwise "invisible" prey.

One completely new experimental exploration will be an attempt to recreate, as close as possible, what the deep-sea looks like to deep-sea animals. The goal is to use data previously generated through research by Tammy Frank and others on what range of light these animals can detect and measurements taken during the cruise by Edie Widder of light levels in the deep. Then, on dives in the Johnson-Sea-Link, scientists will use filters so that only that range of light is visible to them, thus giving the first ever "shrimpeye view" of the deep-sea's alien terrain, which will be captured on video and in photos.

Tammy Frank should also have the chance to conduct detailed studies of how the eyes of animals on the deep seafloor work. Last year, she used special light-tight traps to catch animals for study, because submersible and ship lights can be blinding. But because the number of animals she got with the traps was limited, this year she is taking a new approach.

Harbor Branch engineers have designed and built a new light-tight box that fits on the front of the submersible. The plan will be to place a bait bag on the bottom on one dive, which will attract all manner of deep-sea shrimp and other organisms. Then, on a subsequent dive, the sub will approach the bag with only red lights on, which does not damage the animals' fragile eyes. The bait bag will then be placed into the sealed box, and Tammy will have a treasure of animals to work with in her dark lab on the ship.

To follow along on the expedition, visit @Sea regularly for dispatches describing each day's most exciting discoveries and accomplishments. Also, be sure to visit NOAA's Ocean Explorer webpage for additional reports as well as detailed information on all the Deep Scope 2 research projects.

© 2005, Harbor Branch Oceanographic Institution