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OPERATION DEEP SCOPE Exploring Gulf of Mexico Deep-Sea Habitats MISSION DISPATCH 3 • August 09, 2004 Dispatch by Mark Schrope - @Sea Photo-Journalist 
"We've got a monster shark down here," came the report from pilot Don Liberatore over the underwater telephone as soon as the Johnson-Sea-Link reached the bottom on today's first dive. He and Tammy Frank saw a huge, dark shadow from the sub's front sphere as they approached the bottom at the Brine Pool that turned out to be a roughly 15-foot sixgill shark (Hexanchus griseus). Sightings of sixgill sharks are extremely rare, though this is probably more of a reflection on how little time humans spend in the ocean than of their actual rarity. The sharks are easy to identify because, as you may have already surmised, they have six gills as compared to most sharks, which have five. Sixgill sharks, according to a handy book we have aboard called Fishes of the Gulf of Mexico, were first described scientifically back in 1788. They are often associated with the deep sea but can be found from the surface all the way down to almost 6,000 feet. The sub team filmed the shark for a couple of minutes as it was swimming right next to the Eye-in-the-Sea and showing interest in the bait bag. She then turned and swam directly for the sub. Watching the video later we could hear Don saying, "Alright, buddy, we're backing up, don't worry about it," as he quickly reversed the sub out over the brine pool to allow the shark to pass under. The shark would have posed no danger to the sub itself, but was more than big enough to do some damage to equipment on the front. 
Later the shark came back and began ripping into the bait bag that was eventually found mangled some 30 feet from where it
and its fifteen pounds of weight were originally placed.
After dealing with the shark Don retrieved the Eye-in-the-Sea for its first return to the ship from the bottom. Unfortunately, Edie Widder and graduate student Erika Heine found that the device's camera had not been recording. They believe it was a software problem and so the camera was quickly reprogrammed and returned to the bottom on a later dive today. Similar problems occurred during early tests in California of the Eye, and were overcome, so everyone is hopeful that we will still get plenty of use from the system. Today we also did our first scuba dive to collect small jellyfish for a few ongoing studies of ways that animals are able to hide in the open ocean even when there is nothing to hide behind. It was amazing to see that lurking just a few feet below the ocean surface, which can look lifeless much of the time, is a host of animals including swarms of round 
jellyfish, some almost
a foot across. On closer inspection of waters down to about 45 feet, we also found smaller jellies, but none of the
sharks that commonly come around to visit divers working in open water.
We'll have one more dive on the Brine Pool tomorrow morning then move to an area of methane seeps just a few miles from here. Weather forecasts for this part of the Gulf call for seas less than one foot, or tropical cyclone conditions. We're all voting for the former, but we'll see. 
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