4/11/2015 – Upper Thunder Biology count

Trip date:  11 April 2015
Project manager:  Bill Gee
Trip purpose:  Biology baseline survey in far upper Thunder River
Areas of Cave visited:  Upstream beyond Round Room
Trip participants:  Bill Gee – Rita Worden – BJ Seidel – Dave Seidel – Grace Welch
Entry Time:  9:50 am
Exit Time:  9:20 pm
The trip report:  It has been several years since we did baseline biology survey in far Upper Thunder River.  This trip was originally scheduled for February, but icy roads forced cancellation.

I drove down Friday afternoon and camped overnight at the schoolhouse.  The others came in Saturday morning.  Everyone arrived shortly before 9:00am.  After driving up the hill, we all geared up and started down the shaft.  Rita went first so she could help BJ and Dave get off the rope.  I was last.  We were all in the cave by about 10:15am.  The rain in the shaft seemed to be running harder than I have seen for a while.

Since Dave and BJ were Carroll Cave newbies, we did a quick trip over to Thunder Falls.  They were suitably impressed.  The stream level was 2 or 3 inches above normal, enough to make Thunder Falls fairly impressive.  The water was not turbid.

Rita led the way to the Round room so she could get some practice for the NSS Convention trips in July.  We arrived at the Round room about 11:45am.  Everyone had a snack, then we continued on to the breakdown pile.  As usual, the journey from the Round Room to the breakdown pile had a few twists and turns.  The trail is well marked most of the way, but some of the reflectors are not well placed.  We also took a few extra minutes at the jumping-off spots.  We arrived at the breakdown pile about 2:00pm.

The trip through the breakdown pile took about 30 minutes.  The slightly higher water level made the first pinch a bit more difficult than usual due to the stream velocity.  Everyone got through the three pinches with no trouble.

Just past the breakdown pile is a rather long riffle area where we did the first biology count.  Rita kept the data book while the rest of us turned over rocks to find and measure isopods.  There were not nearly as many as I thought there would be.  We did not see any snails or salamanders.  Survey time was 13 minutes, which gave us enough time to turn over most of the loose rocks in that section of the stream.

From there we went on to the terminal waterfall.  We arrived there about 3:15pm.  We decided to have our hot meal before doing the biology survey at the waterfall.  The survey time was 8 minutes.  We found 2 fish plus several isopods.  This pool is smaller than the riffle area, so it takes less time to count.

The return trip took longer than I expected.  We left the waterfall about 4:45pm.  I hoped to be back at the ladder by 8:00pm so we would have a bit of daylight remaining.  The group was tired and we could not move as fast as I hoped.  We took a break at the Round Room just before 8:00pm and arrived at the ladder a few minutes before 9:00pm.  Everyone geared up and climbed out.  We were all out of the cave by 9:20pm and moving down the hill by 9:50pm.

Data collected:

Bats:  Dave reported seeing one bat during the trip.  I did not see any.  In this section of the cave that is not a surprise.

Snails and salamanders:  We did not see any snails or salamanders during the trip.

Riffle Isopods:

3mm = 2
4mm = 1
5mm = 2
6mm = 2
8mm = 1
9mm = 2
10mm = 5
11mm = 3
15mm = 1

Water depth ranged from 5cm to 25cm.  Water flow was rather fast.  Substrate was rocks 3cm to 15cm across.

Waterfall isopods:

2mm = 1
3mm = 1
4mm = 2
5mm = 2
7mm = 2
10mm = 2
16mm = 1

Waterfall fish:  One each at 50mm, 60mm and 65mm

Water depth ranged from 5cm to 35cm.  Water flow was not very fast, though there was a lot of turbulence from the waterfall.  Substrate was bedrock and rocks from 3cm to 20cm across.

I did an informal fish count for the stream section from the breakdown pile to where you get out of the water.  I counted 8 fish in that part of the stream.  In one place we saw three fish all together.  One of those three looked gravid.

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