Biology trip report 24 May 2008

Carroll Cave Trip Report – 24 May 2008

Project – Biology
Time in: 10:30am
Time out: 4:00pm
Participants:
Bill Gee – Leader
Jeff Page
Matt Niemiller
Andy Isbell
Shawn Williams
Jim Cooley
Pic Walenta

In late summer 2007 Matt Niemiller contacted the Carroll Cave Conservancy asking for permission to enter the cave. Matt is a PhD student in biology at the University of Tennessee in Knoxville currently working on a project to measure the genetic diversity of various populations of the Southern Cave Fish. His method is to take a small snip of fin from several individuals, then run a DNA analysis on it to compare with the other samples.

The CCC Board of Directors reviewed Matt’s request and methods before granting special approval. We’ve tried several times to do this trip. On May 24, 2008 it finally came together.

I drove down to the school house Friday night arriving about 6:15pm. Shawn Williams arrived about 7pm. Pedgie Heinz arrived after midnight to camp. She did not participate in the caving trip.

Saturday morning I drove up the hill about 8:00am. It was thundering and the sky was dark, but there was not (yet) any rain. I installed a new data logger on the rain gauge along with a new protective housing. We should have no more problems with the logger getting iced over.

It started raining about 8:45. Shawn came up the hill and we waited for others to show up. Matt was the first, then Jeff Page and finally Jim Cooley, Pic Walenta and Andy Isbell arrived shortly after 10:00am.

The rain was coming down steady but not hard. We geared up and dropped into the cave. We were all in by 11:00am. Matt and Andy got a good look at the bait sticks near the ladder and near the shortcut to Thunder Falls. They report a lot of critters on them including springtails, beetles, a centipede and some spiders.

The first order of business was to introduce Matt and Pic to Thunder Falls. The river was running a few inches higher than normal. After the tourist stuff was done, we started upstream looking for fish.

As we passed the stilling well, Jeff and I stopped for a few minutes to do a repair job. The previous stilling well was snapped off at the collar where the main pipe was fastened. This left the data logger unprotected. I built a new stilling well which should stand up to high current flows better. Replacement was a simple job of unbolting the old well and bolting in the new. While we were there, I downloaded the data logger.

Jeff and I quickly caught up with the rest of the team. They were finding fish and putting them in a big ziplock bag with some water. The plan was to find and capture 10 fish, then go back and get the tissue samples all at once.

We quickly found and netted ten fish. We let a few smaller fish go. We did not go more than about half-way to UL2 to get ten fish. Matt measured the length of each fish, then used a pair of sterilized scissors to snip a small bit of tail fin from each one. The fish was then released back to the river. The data was recorded in a notebook so Matt can tell which samples came from which fish. The smallest fish we took a sample from was 39mm and the longest was 64mm.

We all trooped back to the ladder to prepare for more fish hunting in Carroll passage. Pic, Andy and Jim decided to climb out while Matt, Jeff, Shawn and I went on. The four of us did a detailed search of as much of Carroll River as we could see from the headwaters near the ladder down to the Water Barrier.

There were no cave fish to be found. We saw three accidental surface fish, all in advanced states of starvation. Matt identified them as various species of sunfish. Two of these fish were farther upstream than I have ever seen surface fish before. Shawn and Matt found a number of juvenile grotto salamanders.

I downloaded the water level data logger in Carroll River as we went by. This logger is near the Totem Pole, about 200 feet upstream from the Water Barrier. The stilling well is bolted to a rock which is sitting in the silt on the bottom of the stream. The rock had tipped so the stilling well is about a 45 degree angle. This will not affect the readings.

When we reached the Water Barrier without finding any cave fish, we were disappointed. However, we did not want to get that wet and we did not want to disturb the bats beyond, so we turned around and went back. We arrived at the ladder about 3:30. Everyone was out of the cave and the hole derigged by 4:15.

Bill Gee

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