Florida Karst Bacteria Collection Project

February 2002

Ethan Brodsky

(Photos by Tami Thomsen)

I have been participating in the Piquette mine project for the last year, collecting bacteria from an abandoned lead-zinc mine in southwestern Wisconsin for study by the UW-Madison Geomicrobiology Lab. I have been diving with Tami Thomsen, lead diver for the project. The researchers were interested in extending their efforts to discover if similar organisms might be found in other underwater environments. On a cave diving trip to Florida in December 2001, she and Keith Meverden noticed two different bacterial mats, stratified water layers, and other interesting sediment depositions. Over a beer one night in Madison, she was discussing her finds with Dr. Sue Welch of the lab, and Sue was interesting in further investigating the finds.

Rock Bluff

Bacterial mat on floor

Iron deposits on wall

We set out for Florida Wednesday afternoon, drove straight through 21 hours, and, upon arrival in Mayo, FL, picked up our canoe and immediately set out for Rock Bluff Spring. Rock Bluff is a quarter mile upstream of the highway 347 boatramp on the Suwannee River and is accessable only by boat (unless you really like to swim). The spring rises from a slit at the bottom of a large shallow pool. It surrounded by a meadow and a small cottage overlooks the spring.

The entrance to the spring is extremely small and we used a sidemount gear configuration to get in. Even with our streamlined setup, entry was still a bit tight - it is amazing that the system was first explored by divers pushing double tanks ahead of them. Once past the entrance restriction, the cave is a bit roomier and splits off into two main tunnels. The left goes on and on and on, while the right is shorter and was the focus of our dive. We collected samples of the bacteria and the surrounding mineral deposits and photographed them in situ. The picture at left shows a bacteria mat, while the picture at right shows an iron deposit on the wall.

After taking the samples out of the cave and putting them on ice in our cooler, we decided to do a second dive to explore more of the cave and take pictures. Just after the bacteria room, there was a second keyhole restriction, even smaller than the entrance. The keyhole is visible below my head - yes, it really is as small as it looks. Sometimes the gravel fills in and blocks the keyhole enough to prevent a diver from getting through - a thoughtful diver has left an entrenching tool next to the restriction (if you look closely, it's visible just to the left of the hole) To get through the restriction requires either removing a tank or, (a) being thin, (b) rolling on your side, and (c) shoving and grinding your tanks through the gravel.

We chose the latter and we were soon through the restriction, into the a room we call the Turtle Crypt. The floor was strewn with turtle shells and bone fragments - evidently they swam into the cave and couldn't found their way out. The passage splits right after the restriction - to the left is a spring tunnel and to the right it siphons. We followed the siphon a bit and found some old bottles buried the silt. While Tami was looking for bottles, I went a bit further, through a zig-zag restriction into a room where the line ended. I turned and discovered I had completely wasted the tunnel (oops), so I had to go back through the zig-zag blind. On the way out, we checked out the other spring tunnels until we hit thirds.

After returning the canoe, we went to the hotel and waited for our friend James Funderburk to show up (remember that we were now 36 hours without sleep) to do a fun dive at Little River. James, however, stood us up, and we ended up sleeping and skipping the night dive.


Friday morning we started early, with three dives planned for the day. We went to Peacock Springs Recreation Area and dove from Waterhole III to the Peanut Tunnel, exiting at Peacock I. We took a quick sample from a bacterial mat and shot some photographs. The striped stick in my hand is used as scale for judging the size of objects in photographs (it was *this* big).


After Peacock, we headed to Bill Rennaker's Cave Excursions to fill our tanks, then hiked what felt like miles through the woods to the small hole (about the size of a 55 gallon drum), that is the entrance to Luraville II (Tami had noticed a anamolous stratified water layer in the downstream section there). We took samples of sediment and water above and below the layer and made some measurements. I tried to lose the sample vials, but fortunately we were in the entrance room when they floated out of the bag (Note to self: when you walk *eight* miles carrying sidemount 112s, be sure to hold the sample bag shut on the way out of the cave!) While Tami manuevered her camera (worth more than her truck) through the hole, I made a short foray into the upstream canyon section of the cave.

Ginnie Springs

After getting lost on the hike back (note: if you cut your hand on the thorn bushes, it won't heal for days), we hurried over to Ginnie Sp rings for lunch at the Cambrian Foundation's annual meeting. While Tami attended seminars, I dove for fun in Devil's Ear. Saturday and Sunday I spent more time working on my sidemount technique in the Devil's Eye/Ear system. I also spent a bit of time attempting to get into Little Devil, which wasn't a good idea, as I don't enjoy being buried by sliding logs and sand.

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Ethan Brodsky <brodskye at cae.wisc.edu>