02/15/2014 – Bio survey upper Thunder River

Trip date:  15 February 2014
Project manager:  Bill Gee
Trip purpose:  Bio survey upper Thunder River
Areas of Cave visited:  Upstream beyond Round Room
Trip participants:  Bill Gee, Kyle Lewis, Nathan Taylor, Meghan Gallo, Derek Thompson, Kayla Sapkota
Entry Time:  10:00am
Exit Time:  7:30pm
The trip report:  It has been several years since the last biology baseline survey in the far reaches of upper Thunder River.  Getting through the breakdown pile at the “mapped end” is a challenge, as Jim Cooley discovered a few years ago.

I drove down Friday after work and camped at the schoolhouse.  Nathan also came down Friday night, arriving around 9:00 pm.  When we got up Saturday morning, the Weather Service reported 12 degrees in Osage Beach.  It was cold!  Fortunately the roads and fields were dry, so getting up the hill was not a problem.  There was almost no snow on the ground.

I went up the hill about 8:00 am to open the cave and get the rope rigged.  It is a good thing I had a propane heater in the truck.  The outer lock on the silo was frozen.  I had to thaw it out before it would unlock.  The inner lock – indeed, almost everything in the silo – was covered in a rime of frost.

The cave was blowing out VERY strongly.  It did not take long for the silo to turn into a London fog.  It warmed things up to a more bearable temperature, and also started a near rain storm.

Nathan and Kyle arrived at the silo about 8:45.  Derek, Meghan and Kayla arrived very shortly after 9:00am.  We all geared up and were in the cave by 10:15 am.

The first leg going to the Round Room took about 40 minutes.  We arrived there about 11:30 for a 15 minute break.  As we left the Round Room, we opened and verified the contents of the rescue cache.  All is present and in good shape.

It took a bit over an hour to get to the breakdown pile, including a short side-trip to admire the Second Azure Pool.  We took a pause for a candy bar break just before starting through the breakdown pile.  The trip through the breakdown pile was accomplished with no incidents.  We arrived at the first biology site about 2:00 pm.

The isopod count at the first riffle took about 20 minutes.  We measured some of the biggest isopods I have seen.  Several were almost 20mm long.  Almost all of the isopods over 15mm were in the central part of the riffle.  Isopods from either end tended to be smaller.

We then went on to the waterfall, arriving there about 3:00pm.  A quick search of rocks revealed only a few isopods and a couple of fish.  After taking photos of everyone standing by the waterfall, we retreated a few hundred feet back down the cave for a hot meal break.

We started the return trip about 4:15 pm.  The only adventure we had was taking a wrong turn to go through the Bone Room instead of around it.  Otherwise it was just a matter of slogging along.

The return trip to the ladder took about three hours.  We arrived just after 7:00pm.  Everyone geared up and climbed out.  The outside temperature was about 34F, barely above freezing.  Getting changed out of wet clothes was cold work!  We all were changed and the cave closed up by 8:00pm.

As we moved through the cave we regularly saw cave fish.  The only fish we counted were upstream of the breakdown pile, but in the rest of the trip we saw probably 20 or 30 fish.

Data collected:

Isopod counts at the first riffle.  This is upstream from the breakdown pile at the first riffle after getting back into stand-up cave.

2mm = 7
3mm = 3
4mm = 6
5mm = 2
6mm = 1
7mm = 1
8mm = 14
9mm = 3
10mm = 10
11mm = 4
12mm = 8
14mm = 1
15mm = 4
17mm = 5
19mm = 3

1 snail.

3 cave fish

From the pool at the terminal waterfall:

5mm = 1
10mm = 1
12mm = 1

4 cave fish

1 tri-color bat

Bill Gee

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