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DISPATCH 3 | 06.05.2007 | Diving Sink Hole B There are a series of sink holes that occur along an escarpment 14 miles offshore in depths of about 900 feet off Of Key West on the Portales Terrace. These sinkholes were first reported in 1954 by Jordan who was with the United States Coast and Geodetic Survey. Sinkholes are common in mainland Florida and typically form by the dissolving action of corrosive acids absorbed from surface waters on the limestone and calcareous deposits that make up much of Florida. Until recently it was thought that these offshore sinkholes were evidence that this escarpment was at one time above sea level, but recent work by Land and Paull suggest that these sinkholes actually formed underwater and are evidence of mixing of saltwater with the Florida aquifer leading to the subsequent formation of the sinkholes. 
In 1999 our group explored the Jordan and Marathon Sinkholes using the
Johnson-Sea-Link submersibles
and found them to be incredibly interesting. The bottom of the Jordan sinkhole is filled with "sediment" made
up of tiny shells from over 20 different small organisms, mostly Pteropods. The bottom of the Marathon sinkhole
was rock and sand and we found hundreds (if not thousands) of fossilized Dugong bones strewn across the bottom.
Not really believing what we were seeing, we sent the bones off to experts at the Smithsonian who confirmed that
they were indeed rib bones from Dugongs that lived during the Pleistocene. Dugongs are related to today's manatees
and typically live in shallow swampy areas. Why there are large accumulations of these fossils in the sinkholes
is still a topic of debate on the ship, but there are reports that they also occur elsewhere on the area known
as the Portales terrace. Perhaps they simply fall in and are trapped in the sinkholes. Both sinkholes contained
unusual and different organisms that were useful in our drug discovery program and we have decided that exploration
of more sinkholes would be useful.
Today's first dive will be in a sinkhole that no one has ever made a dive in. It is one of three that were simply called Sinkhole A, B and C by Jordan. Sinkhole B lies along the same bottom contour as the Jordan and Marathon Sinkholes. The maximum depth of the sinkhole is 1336 feet and the top of the sinkhole is about 900 feet. We are hoping that the walls will be rock and hold an abundance of sponges and soft corals for our investigations. New submariner Chip Baumberger will describe the dive. Little Fish Enters The Big Pond - Rex "Chip" Baumberger 
I began my fish biology career about 8 years ago, conducting stationary census of reef fishes on SCUBA. As an intern and later as a Master's student, I have honed my techniques on coral reefs and currently catalogue species on reefs throughout south Florida. I feel as though I have a good grasp on the visual identification of fishes from these reefs; however the deep sea is something completely different. I have even taken a fish biology course taught by two preeminent deep sea icthyologists, but none of these experiences prepared me for what awaited us at Sinkhole B in the Pourtales Terrace in the Florida Straits. I was selected to dive in the Johnson-Sea-Link II submersible on Tuesday, June 5 at 0800 hours. I was so excited, I hurried off to my rack early the night before to ensure I had enough sleep to attend the 0600 fathometer mapping, 0630 breakfast and 0730 pre-dive briefing, followed by the 3 + hour dive. After receiving advice from numerous submariners and other students, I clambered into the submersible with my heart racing. A moment later, I was already glued to the starboard porthole, where I would remain for the better part of 4 hours. I paid attention to a simple safety briefing ensuring I would be able to act in the event of any emergency, much as I doubted the occurrence. My friend Jimmy happened to be the subcrewman in the back with me, so that certainly eased any anxiety that might have crept into my psyche. We got as comfortable as the cramped quarters would allow, me with empty bottles and a cooler for water samples, and Jimmy with his laptop for an in-flight movie. These rides are old hat for the sub guys, and I imagine they have seen many amazing things, but the porthole is barely big enough for one person's eyes, so they graciously give up the chance to see the newest exciting discovery for first-time students like me. 
I was pleased to be on a dive with our most experienced submersible pilot, Don Libertore, and Dr. Amy Wright, head of the BMR program, whose enthusiasm seeps into everyone around her. Fortunately, Amy is also a fishing buddy so she indulged my desire to document each of the fishes we saw during the dive through her skillful manipulation of still and video cameras on the submersible. We ascended quickly through the great blue, until the light attenuated to dark and we continued down with light solely from the JSL. When we were 50' from the bottom, at 1300 feet, there were some loud exclamations "Look at all those fish!" and some ooohing and aahing followed from the sphere. Just before Don switched the light on to the starboard side where I was affixed to the porthole, I saw what the hub-bub was all about. In the back-scattered light from the bright front spotlight which was chasing fish away from the JSL, I saw the thousands of silvery bodies massed up in a writhing pile, by far the densest aggregation of fish I had ever seen. So what did I do as a budding fish biologist? I fumbled the call and drew a blank on what species they were. When a seasoned 
professional who has been on thousands of dives and a scientist who has been diving for 20 years asked me what species of fish they were, I had nothing. I took a couple of guesses based on the body shape, but I still haven't figured out what they were.
Fortunately, Don is adept at using the manipulator arm suction tube so he was able to capture two of the fish for later identification and Amy graciously gave up one sample bucket for my fish. Somehow in all that excitement, I remembered the water samples I needed to collect, so Jimmy cracked open a valve and filled the 6 water bottles. We stowed them in a false floor (along with our stinky shoes) that covers the bottom hatch we climbed through earlier. Once that one-foot cube was stowed, we had more valuable real estate inside the rear compartment. Of course this extra space allowed me to behave in my child-like, 'would you sit still' (as mom used to say), manner. 
I spent the next three hours in absolute awe, (not speechless awe, I couldn't shut up)! How a "fish guy" ended up on this dive was certainly fate, and the fun had only just begun. We saw blackbelly rosefish and Anthias, then a Berax, followed closely by three silky sharks. The video captured most everything, including a small orange disk-shaped fish, I think may be called a Dory, but my fish bio course was last year, so I have to look it up! I'm delighted to have photos and videos, they will allow me to complete my species list. I also assisted the front sphere with locating sponges along the vertical rock faces along the side of the sinkhole, and remained in awe of Don's sampling. He makes it look so effortless, but Jimmy told me he tried it and it's not at all easy. If Jimmy, who can fix anything on a boat, says it was hard, I know it was! We took some wonderful photos of Bamboo corals, Black corals, gorgonians and sponges, Amy wished we had more, but a large Yellow seafan was our best sample. All too soon, our journey came to an end. We traversed the entire wall of the sink hole from a depth of 1350 feet up to the edge around 900 during our dive. We began the quick ascent back to the surface, rising at 100 ft per minute much higher than my typical SCUBA safe ascent rate of 30 ft per minute! I watched the bubble trails left by the rapidly rising sub reflecting the downwelling light on a pure oceanic blue background, magical. 
Once up on the surface, I barely had time to reflect before we were swinging from the Seward Johnson A-frame, and back onboard. I took my water samples and some of the best memories I could hope to have out of the JSL and back into reality. This sub dive has left an indelible impression in my mind, and I have video and photos to remind me and samples catalogued away that record my participation in this most unlikely, lucky event. I feel changed forever, this reef fish guy may have just become a deep water convert...or at least now I respect the deep fish guys even more. 
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