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DISPATCH 4 | 06.06.2007 | Returning to Sink Hole B The submersible is launched from a huge device called the "A-frame" that picks the sub up off the deck and then the entire A-frame is lowered behind the ship allowing the submersible to be suspended over the water. A series of winches and release devices are operated by the ships' engineers that lower the submersible into the water and release it from its tether prior to the dive (can you tell I am not an engineer?). 
It's a fairly elaborate piece of equipment and
unfortunately on Tuesday afternoon there was a small equipment glitch with the A-frame and so
the afternoon dive in sinkhole B was cancelled and rescheduled for this morning. This morning's
dive will explore the opposite wall of the sinkhole. Our fathometer transects show that it is
less steep that the Southeast face and we expect that it may have different organisms.
Shirley Pomponi will lead the morning dive as scientist
observer in the sphere with first time
submariner Kate Douglas riding as observer in the aft chamber.
First Sub Dive! - By Kate Douglas Big day today! I'm going down in the sub!! My experience on the research cruise so far has been incredible, I've learned so much, but I have a feeling it is about to get ten times cooler. I'm taking another step in unraveling what it is like to be a marine biomedical researcher. This is the exploration bit and I today I will experience what it feels like to literally go where no one has gone before. 
Scheduled to launch at 0800, the
Johnson-Sea-Link will depart for Sinkhole B this morning. Sinkhole B is a 400 ft depression in the ocean floor, about 3000 feet in diameter and 1300 feet deep, located 50 miles south of the Florida Keys. Today we will be exploring the north and east sides of the sink and hope to collect sponge, coral and sediment samples for the lab.
The launch into the water was smooth and very exciting, but my first glimpse of the bottom was breathtaking. We lost ambient light around 800 feet and shortly thereafter the sub's lights began to reveal a rocky bottom, it seemed to materialize out of the darkness. We were at 1354 feet. The external temperature read in at 10 degrees C (39 degrees F), and soon the aluminum cabin would be feeling close to the same. We landed in an escarpment of reddish-brown rubble. The pieces were about the size of those salt and pepper shakers you find on a restaurant tables, and they were everywhere. Turns out we had landed on a collection of dugong bones!! Fossilized and most likely millions of years old, the remains of these mammals (closely related to the manatee) may have settled here after being transported into the sinkhole by currents. We collected a scoopful and then collected a gorgonian growing nearby. We also saw a few dozen fish swimming over the rubble on our descent. They were approximately 12" long, silver, and seemed unbothered by the sub's presence. Our next stop was the center of the sinkhole at 1356 feet. On our way there I watched large and small shrimp, a few starfish, hermit crabs, eels and crabs putter around their bottom habitat. The reddish-orange gallatheid crabs were neat to watch, with their long and spindly arms and lobster-like tail that they curl up under their body. Shirley was excellent in identifying and commenting on the fauna that we were passing; between the video footage at the front of the sub and the view from the portholes on the side, my dive turned into an interactive personal presentation on the deep! The center of the sinkhole was carpeted with a layer of grayish-white shell hash, about 10 cm thick. Don attempted a punch core sample but the shells were not consolidated enough to stay in the sampling tube. If this much life was at the bottom, what was living on the wall?? The wall was by far the most impressive part of the dive...the sheer scale of it was huge. A boulder patch lay at the base of the wall (1354 ft), located about 400 feet from the center of the sink. Looking up, the wall appeared to be composed of a collection of large boulders. A dusting of light brown sediment collected on some of the horizontal surfaces. At 1335 ft, we saw a large white Geryon crab on a ledge of a boulder...and his carapace was just over 25 cm, he was huge!! I saw all different kinds of fish near the bottom ledges of the wall, some were stationary and looked similar to the lizard fish you see in the Caribbean, and others were mobile and had tails that made them look half rat-half fish! 
The 400 foot wall became steep pretty quickly; it slope ranged from about 60 degrees to completely vertical and its surface was characterized by ridges and outcroppings. Don found a rock archway that was so big the sub could almost fit through it. The archway looked like the mini cave, but it wasn't too deep because we could see the back wall when the lights were on it. There were different types of coral and sponges in this area, many of which were collected. We saw pink stylaster coral, white and yellow gorgonians with brittle stars clinging to them, white cup sponges, white raspalid sponges with such a lacey structure that I mistook them for coral, and different types of encrusting sponges. One type of encrusting sponge, the sclerosponge, is neon blue and another, spongosorites, is neon yellow and can encrust on other sponges. We found a large community of black coral but couldn't collect any of it because the animal is protected. We even caught a quick glimpse of a 12-15 ft shark!
As we approached 900 feet, the wall's vertical slope turned into a horizontal plateau and we had reached the top of Sinkhole B. Our last sample was taken here; it was a beautiful white gorgonian. There were a few white sponges spotted in distance. We also noticed some human impacts on the environment, like soda and beer cans, a 55 gallon barrel, some cloth-like material, and a steel rod. The saddest part of the dive was hearing the words "Request permission to leave the bottom" radioed up to the ship. I spent my last seconds on the bottom glued to the window trying to take in every last bit of the scenery. Today I had the opportunity to explore an environment that nobody has ever seen before. The excitement and anticipation of what lay just beyond the sub's lights was an experience unlike any other, its not every day that you discover a new species! But the three hour deep ocean dive didn't just open my eyes to a new world, it showed me that adventures like these are critical to understanding certain aspects of our own terrestrial world, like the development of anti-bacterial and anti-cancer drugs. I hope that by communicating experiences such as these, others will become excited about deep ocean reef exploration and by the promise of discovery. All in all, my first trip to the bottom of the ocean was an unbelievable experience whose impact will last for many years. Transect Party and Sink Hole C One of the activities which is on-going much of the time that the submersible is not in the water, is mapping the bottom to find new dive sites. I call these the "transect parties" because many of the scientists gather in the Wheelhouse to help and to watch the action. It's a bit of a social thing (except when it happens at midnight or 4 AM). John Reed and his merry band of "Transectors" (The Transect Team) have been up in the wheel house each afternoon and evening working with the crewman on watch to drive the ship in a grid pattern and using the fathometer, measure the depth of water under the ship. This allows us to detect featuers that differ from flat bottom. John has combed the literature and picked all of his colleagues' brains to pull together everything that is known about deep-water sites of Florida. Some of the information comes from as long ago as the 1880's when dredges were conducted. He has compiled all this information into a database that he can search and he has also put them into a chart with color and shape coded boxes that suggest different types of dive sites. Some of the sites come from multibeam maps we have obtained from Mark Grasmuek and co-workers at the University of Miami, Rosensteil School of Marine and Atmospheric Science. These maps show some interesting new sites and we are keen to confirm their accuracy. 
The Transect party starts by entering the reported coordinates into the ship's navigation system and beginning to run in parallel lines over the feature. The feature could be a sinkhole or a ridge or what we often call a "bump"- which could be a deep-coral reef or a hill or a sand dune...Our goal is to confirm that the sites on the charts or maps are really where we think they are. The last thing we ant to do is drop down and look at a flat mud bottom, a quarter mile from the actual dive site.
The "Transect team" uses a GPS based tracking program to mark waypoints (Latitude, Longitude) that are then coupled through time readings with the fathometer display. It's a pretty sophisticated process, one person sits next to the fathometer output (it shows up on a computer monitor) and when they see a change in the bottom profile, they yell out the depth and a comment (going up, going down etc.) to the other members of the Team. Another person sits at the tracking station marking the waypoints and typing in comments (going up, going down, etc.). We call this process "running a transect" and on some days, at least three to four if not sometimes eight to ten hours of each day are spent profiling the bottom (much of it at night). Of course there are much more sophisticated ways of mapping the bottom (multibeam acoustic systems etc), but we don't have one, and they cost a lot of money, so we work with what we have. The transect team is looking for unusual features on the ocean floor that suggest the presence of deep-water coral reefs, rock outcrops, bioherms, lithoherms, sinkholes, anything that looks different than the slowly deepening flat bottom that is most of the Portales terrace. Having the RSMAS deep-water charts which were generated using Multibeam sounding, has been a huge help in finding new sites to dive, but much of the Portales Terrace remains unmapped and so we continue to transect looking for new features using charts as a starting point. Over the past few evenings our Transect Team has profiled each of the sinkholes and this afternoon's dive will be in Jordan's Sinkhole C. At its deepest, sinkhole A is 1372 feet deep, up on the rim of the sinkhole its 992 feet deep- and it's a pretty big one- 846 feet across. Riding in the sphere is myself. Amy Wright with pilot Craig Caddigan and riding in the back is new submariner Jennifer Choate with Submersible Technician Frank Lombardo. Submersible dive #3591 - By Jennifer Choate The date was June 6, 2007. The time was 16:00 EST. The event was my first dive in Harbor Branch Oceanographic Institution's submersible, the Johnson Sea-Link II. Our ship, the R/V Seward Johnson , had already made several stops for dives at specific locations, ranging from Dry Tortugas to south of Key West. It was now positioned off the Florida Keys, ready for my dive. 
I spent the hours preceding the dive in nervous anticipation. I was excited at the prospect of exploring the depths of the ocean, yet I felt anxious about spending several hours confined to the back of the sub. The space is very limited! In fact, before we left Harbor Branch, I was unsure that I would even make the dive. After much thought, I came to the conclusion that this was too great an opportunity to pass up, and I decided to go for it!
Fifteen minutes prior to launch, a short pre-dive meeting was held, and an overview of the dive plans was presented. Then, we went outside to prepare for the launch. Following a quick set of instructions given by Frank, the sub crewman for my dive, I entered the back of the Sea-Link II. Frank climbed in after me and closed the hatch. He gave me a quick safety briefing, and we were ready to go! As the sub was lowered into the water, the anxiety I felt going into the dive disappeared. When reached the water, I looked down out of my small window. Hundreds of feet below us lay our target, sinkhole C. At almost 1400 feet at its deepest point, it promised to contain lots of interesting specimens. 
Our descent began almost immediately after hitting the water, and we reached the sinkhole fairly quickly. As we descended, the light from the surface slowly faded until it was pitch black. The presence of bioluminescent organisms made the trip down beautiful.
The sub arrived at the bottom of the sinkhole amid many small fish. We moved along the bottom and up the south wall of the sinkhole looking for sponges, corals, and other samples for collection. I spent half of my time watching the video monitor, and the other half looking out of my window. The sinkhole was composed of mostly sediment, with some rocks. Sponges, corals, urchins, sea stars, sea cucumbers, and even an octopus were present. We spent roughly three hours at the bottom, exploring and collecting. Then, it was time to return to the surface. Bioluminescent organisms were present, making the ride up just as beautiful as the descent. Upon reaching the surface, we were lifted from the water to the ship, thus ending my first submersible dive. It was an amazing experience, and I hope to someday repeat it. 
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