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South Trelawny
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Mar 29, 2004

GREEN GROTTO - WILD CAVES


Position:
Green Grotto Main Ent: WGS84 - 18 27' 37.7" N, 77 22' 26.7" W, +/- 5m
Green Grotto - Wild Caves Lighthole 1: WGS84 - 18 27' 35.6" N, 77 22' 38.3" W, +/- 10m

Field notes: R. S. STEWART

Cavers: R. S. Stewart, A. Engels, D. Williams.

Time in: 12:30 EST, Time out: 16:30 EST

THREAT VULNERABILITY: High

This was the first of four days that would be spent by Guy van Rentergem, and the JCO, at the Green Grotto - Runaway Bay Cave complex in St Ann. Guy had produced a superb, accurate, map of the tourist part of the caves, for the UDC, in 2001; one of his greatest priorities of this expedition was to finish the survey by extending it into the non-tourist part of the caves, the "Wild Caves".

I would only be in attendance for this first day. The other three, I would be teaching a Workshop in map-reading and orienteering at the Windsor Research Centre, in Trelawny, to members of the Ja Forestry Dept. Fortunately, one of our American Peace Corps volunteers, Dietrich Roggy, was able to assist Guy during those three days, and Adam Hyde pitched in on two days.

Upon our arrival at Green Grotto, not long past the arranged 10:00 AM, we met with a representative of the company that manages the tourist operations and took care of some paperwork. This was soon done and our caving could begin.

We were to meet Adam for the day's session, and as he hadn't arrived yet, Guy took the opportunity to show us around the tourist section of the caves. I must confess to finding it bizarre in the extreme, this being the first true tourist cave I had ever visited. There were lights, benches, potted plants, water-dispensers, signs, and the whole thing looked like it had been freshly swept. Being more used to getting covered with mud while stumbling and slithering through systems where the only water-dispensers are potentially flooding passages, this all seemed very unreal. For what it's worth, though, as a tourist operation, it appeared to be very well run and very well kept.

The plan was that we would split into two teams; Guy and Adam, with the help of Dietrich, would explore other caves, in the vicinity of Green Grotto, that had been found in 2001; I would look for new passages in the Wild Caves, assisted by Andy Engels and Delroy Williams. Accordingly, Guy guided my team to the entrance to the Wild Caves, and as we headed in, he returned to meet Adam.

There are several ways into the Wild Caves: three openings, part way up a 15 m rock-face that overlooks a large crevice; at least one lighthole entrance located some distance away; and underground by way of Green Grotto. We will call the three openings on the rock face "Green Grotto - Wild Caves Ent 1", "GG-WC Ent 2", and "GG-WC LH(Lighthole) 1". Ent 1 is vertically oriented, about 3 m up the rock-face, facing NW, about 80 cm in height, and 2 m wide, and it leads into water. Ent 2 is several metres higher and about 10 m to the SW, vertically oriented and about 1 x 1.5 m, (not measured) and leads into a chamber connected to that of GG-WC Ent 1. GG-WC LH 1 is horizontally oriented and is in effect a lighthole several metres away from, and above, GG-WC Ent 2, sitting on a terrace that is a wide step part-way up the rock-face. All three of these openings require a bit of a climb up the rock-face to reach. The more distant Lighthole was seen only from the inside; the topographic position is unknown.

The WGS84 L/L position given above was derived from a GPS position, (wpt's 54/55), taken on the step, 12 m, az 270 deg true, from GG-WC LH1, with distance and bearing determined using tape and compass, after we had exited the cave. Because of the rock-wall above the step, it took me close to 30 min's to get a decent fix, waiting for a better satellite orientation. The position was taken with only 5 sat's, plus the WAAS sat, so I am giving the error as +/- 10 m. It might in reality be somewhat better than that.

The layout of the system, determined during our following exploration, is complex, with development having taken place on two levels. Both levels consist of multiple, connected, circular/oblong chambers, with diameters from roughly 5 to 15 m. The two levels intersect in many places, where the floor of the upper level has fallen into chambers below. The chambers on the upper level are larger and dry. Those below are less large, in places choked with breakdown material from above, and widely flooded with brackish water up to 1 metre deep.

Our time spent in the cave consisted primarily of my finding all the chambers, comparing this to the intial, rough map that Guy had done in 2001, and then looking for new parts of the cave. My two companions, Andy and Delroy, were very new cavers and thusly a certain amount of time was taken in shepherding them and also making sure that I didn't get us lost. Three times, I took us well into the cave, then returned to the entrances, thereby ensuring that I had the layout set in my mind. At the furthest point, not far from where a connection is made to the tourist part of the cave, there was an unpassable, overhung drop of about 3-4 m which stopped us in that direction due to lack of vertigear. I regret having not brought along at least the long etrier; that would have been enough. Nevertheless, I was able to become familiar with the accessible part of the cave and have a good look at the biology.

It should be noted that we almost lost Andy down one of the openings from the upper level to the lower level at one point, (where coincidentally Guy took a picture several days later). Fortunately, Andy recovered and didn't slide onto the rocks below, for even though the drop was only several metres, a broken bone or two would have resulted. For his part, Delroy found the mud very tough-going in spots and I had to park him several times while Andy and I forged ahead.

After a number of hours of poking around inside, we headed back out, I got a position, and then we returned overland to the tourist part of the cave to link with Guy and the others.

Biologically, this cave was a first for me, it being my first coastal grotto. The brackish water in the lower levels was full of marine life, consisting of small barnacles and various unidentified small swimming creatures. The bat numbers were quite high, with most of the available roosting space being used. Guano was present in large amounts, but few of the more familiar inverts were seen, (although American Roaches were present, of course).

Geomorphologically, this cave was also a first for me. The chambers were obviously carved by tides and waves rather than percolation and flow. The two well-defined levels apparently indicate two periods with differing sea-levels. The entire structure of the cave was strikingly different than inland systems.

Hydrologically, this system is intimately connected with the coastal waters beside which it sits. It would be interesting to sample the salinity of the water in various parts of the cave.

I am listing the Green Grotto Wild Caves as having a high threat vulnerability for several reasons: the potential for the currently used part of the system to be expanded into this relatively undisturbed section; the proximity of the cave to substantial local human populations; the potential for pollution via both inland, and coastal sources.

It would be unwise to extend tourist activities into the Wild Caves at any time in the future. This part of the system retains some of the original, unique biology of the now transformed sections of the system, and should be set aside for conservation reasons.

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