Carroll Cave Biology Trip Report

September 13, 2003

 *Trip Leader:  Lawrence Ireland

*Date of trip:  2003 September 13

*Project Manager:  Lawrence Ireland

*Purpose of trip:  originally, to census cavefish in upper Thunder River and to inspect Carroll River headwaters; objectives changed to bioinventory of Carroll River passage

*Areas of cave visited:  upper Carroll River passage (T-Junction to Lunch Room)

*Participants:  Paul Witteried, Janet Aydt

*Time of entry:  10:00

*Time of exit:  18:30

*Trip Report:

                Our September 13 Carroll bio trip consisted of two separate parties.  Please see Bill Gee's trip report from the same day for more on our activities.

                After waiting a few minutes for some late arrivals to show (Jeremy Eaton, Gordon Geldhof, and Paul Woods did not attend), our group of six started to drop the entrance.  Onondaga Cave biologist Eugene Vale arrived in time to try the descent, but declined on account of a mild claustrophobia.   Meanwhile, Janet Aydt, Bill Gee, Paul Witteried and myself took a look at Thunder Falls.

                Our plans for looking at the fauna of Thunder River were dashed when we saw the stream's high flow and turbidity.  Isopods, cavesnails, and even a flatworm (Bill Gee's "unidentified animal", and discovered only twice ever, now) were found on rocks underwater, but the current would easily wash these animals downstream.

                We improvised a new plan back at T-Junction and split into two groups.  Bill Gee, Andy Isbell, and Aaron White went to destinations up Thunder River while Janet Aydt, Paul Witteried and myself decided to continue the bioinventory of the Carroll River passage.  On August 17^th, a group of four counted animals from T-Junction to the Water Barrier, so today we would continue as far past there as we reasonably could.  We left the landing at 12:45.

                It was nice to have some idea how to best navigate through this trampled passage, thanks to the work of the Restoration project.  Our opinion of the trail through this well decorated stretch of cave is that many more markers need to be placed to keep traffic from wandering (i.e. everything looks like an elephant trail).  In some places the best route is not obvious, and in one place two different routes are marked (depending on the direction from which the area is approached).  The speleothems have certainly suffered from years of uncontrolled access.

                One of the first biology objectives we considered was the origin of Carroll River.  Water collects in wide, shallow drip pools below formation areas along the passage's walls.  These pools, which lie in what was obviously once a much more active streambed, eventually coalesce into a small trickle before the water is again ponded up at the Water Barrier.  We saw no evidence of a discrete influx of water until we reached the trickle issuing from Bear Claw Passage, downstream from the Water Barrier.

                As for cave organisms: on our way to the Water Barrier, we noticed salamander tracks in the stream, and in the one place where a good riffle finally occurred, we found two isopods.  I also noted that there appeared to be far fewer bats present than we had counted a month prior.

                We finished a quick break and started our bioinventory at the Water Barrier at 14:00.  We censused a variety of animals and noted the time at landmarks to keep track of our pace.  Besides the bats, which were very scattered this time of year, we found nearly all of the terrestrial animals in our census at or near guano piles.  The frequency of stream inhabitants increased markedly downstream of the guano deposits.

                Altogether, we found the following animals in these numbers:

                Nearly every riffle contained at least a few isopods, but they were much more abundant in sites downstream of guano mounds.  Some very large (>1 cm) individuals were observed, unlike all the small ones we've found in Thunder River (two different species?).

                Carroll River is the only passage in which I've seen terrestrial, adult grotto salamanders, probably owing to the availability of terrestrial prey associated with the bat guano.  Rather than scouring the guano, however, all the specimens we saw were in or near the stream.  One of the adults appeared to be a gravid (egg-bearing) female.

                I was very surprised to find cavefish in Carroll River (particularly given the intrusion of epigean fish species downstream, at the natural entrance).  Most (five of the six individuals we saw) were downstream of the guano piles.  As in Thunder River, the cavefish also tended to occur immediately downstream of riffles.  It would be interesting to study the genetics of the Thunder River and Carroll River cavefish populations.  How long have they been separated, or do they represent the same population trickling in from interstitial spaces in the bedrock somewhere upstream of both these caver-accessible waterways?

                Bat identification was difficult at times, and thus some of our claims should be regarded as tentative.  The summer gray bats certainly contribute to the life of this cave.  We counted at least 11 guano piles, ranging from 1.5 to 21 square meters.  Some were dry and dormant while others were still black, molded, and stinky.  The size of the mounds mostly increased as we neared the Lunch Room and the natural entrance.  The fresh guano deposits contained innumerable fungus gnats and cave beetles.  The dead bats we found associated with these areas sometimes contained troglobitic millipedes and mites.  Another big surprise of our day was discovering a tiny, web-spinning, troglobitic spider.  (Cave-adapted predators only inhabit high-energy sites where there are lots of prey.)

                We had done a good job staying ahead of our silt in the stream but eventually the water became black and brown as we stopped to examine the guano mounds.  As we approached the Lunch Room, the passage became larger and more complex.  Quagmires and breakdown became obstacles.  The last stretch of our bioinventory was a little faster as we hurried to reach the Lunch Room before our turn-around time.  We reached that destination at 16:15.

                On the way out, our party moved a huge, rusty ammo can closer to the new entrance so that it might be removed someday soon.  This ammo can is full of trash and spent carbide and represents a hazard to the cave's biology.  We collected another old carbide dump and put it in the can on our way out.  Discovered near the Lunch Room, we finally dropped the box after negotiating the Water Barrier.  (After this the speleothems and low ceiling will make its removal precarious.)

                Our exit, from the Lunch Room back to T-Junction, took one hour.  After our punctual rendezvous with Bill Gee, Andy Isbell, and Aaron White, we all successfully made it up the ladder.  Even after so much recent rain, the water coming down the shaft was not noticeably greater than normal.

                In conclusion, while the bioinventory of the "T-Junction to Water Barrier" stretch of Carroll River was exactly what I'd expected, I was surprised to see so much life near the Lunch Room on this trip.  There are many opportunities for biological research in this part of the cave.

                Several tasks come to mind in light of our day's discoveries.  A bat expert should be invited both to tutor us with live bat identification, and to take a better estimate of the colonies using the roosts (based upon measured guano coverage).  Because it is apparent that maternity colonies are using sections of the cave as deep as this, we will need to minimize or prohibit disturbance during the summer months.  After each of the guano mounds are identified and measured, fungus gnat and cave beetle population densities could be estimated.  The small number of cavefish we found needs to be monitored, especially if this is a disjunct population.  Of course, a couple people could certainly put in a good deal of work just transporting that old ammo can out of the cave, too.

                I want to sincerely thank Pete, and Janet for driving FIVE HOURS, for making our trip a success.  The participants on my team were especially observant, helpful, and tough.  Although our objectives had to be changed at the last minute, I think we had a great day.

Respectfully submitted,

Lawrence Ireland