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Safety & comfort ] sched_sp06 ] Asmafines ] Limestone Forest ] Lost Pond ] [ Pagat ] Tarzan Falls ] Ritidian ] Mangroves ] LeoPalace ] Fruit World ] Reef walk ] Jocson's 3D maps ] Marine Preserves ] Topo lab ]

Students cool off in Pagat Cave. The cold water is part of Guam's northern
water lens. The level of the water changes as the ocean tide rises and falls. 
Why is that?

3D map

Pagat cave and coastline

Pagat Cave gives us a peek at the water lens: the underground water supply of the island. The cave formed when a more readily soluble part of the limestone dissolved away, leaving a hole with a pool in the bottom.

We will walk down the cliff through some beautiful limestone forest (review of Limestone Forest and Lost Pond trips). We go past the cave and pass through an ancient Chamoru village (latte stones, grinding stones), arriving at the northern coastline (cut benches). Finally we return to the cave and go in to explore the water lens.


Bring a flashlight. The cave is dark, as in no light. Waterproof: while you need only get wet up to your knees, swimming is pleasant. Or you might drop your flashlight. Also remember that wallets and watches may not be waterproof.

You will need sturdy footwear. The hike is like Tarzan Falls -- the terrain is like the limestone forest around Lost Pond.

You can take your time on the way out. However, if you thought the Tarzan Falls trip was too much for you, this one will be, too. It's further and steeper (but shadier).

Carry at least one quart of waterand drink it! Hat highly recommended.

On the positive side:

It's really cool (literally and figuratively) in the cave.
There are no bats in the cave.
You can do the hike and not go in the cave if you prefer.
The scenery is some of the best on Guam, with the cultural bonus of the latte site.
You'd be crazy to miss it, unless you'd be crazy to take it.

The trip will take up the full lab period. Be at the lab sharp at starting time.
If you feel this climb will be too much for you, you may get credit for minding the vehicles.

Stay with the group at all times.

At the shoreline, don't go across the arch over "the washing machine". 
In the cave, don't break off bits of the stalagtites or stalagmites or touch them!
Leave them for others to enjoy. Grease from your fingertips can stop their growth. Don't drink the water in the cave! It may be part of our water supply but it hasn't been treated (chlorinated).

Permission to pass:

Guella yan Guello dispensa ham lo Ko sia manmanbisita ham guine gi lugt miyu?
Guella yan Guello, dispensa ham lo Ko sia ham manmaloffan yan manmanbisita gi tano miyu sa' yanggen un bisita i tano'm mi faloffan-ha' sin un famaisin.

Limestone forest on the trail to Pagat Cave. You will see many familiar trees
and herbaceous plants, including lots of bird's-nest fern. Review the limestone
field trip.

Cyrtophora web community. There are lots of spiders in Guam's forests
now, perhaps because there are no insectivorous birds to compete with them.

On the way down (or resting on the way up!)  look at the orb web spider communities. These are communities -- not populations -- The domed webs are like condos, and have several inhabitants. Compare spiders in the centers of the webs and look for different spiders around the edges -- these are web parasites that don't build webs but use the other's web to catch food. How many different ones can you identify? Males and females of orb spiders and the parasites are quite different from one another (dimorphic). The web builder is Cyrtophora mollucensis, big female in middle of dome, with egg cases; males much smaller, same shape but orange front. The thin silvery parasite is Argyrodes sp. -- larger are females. They build small egg cases with flared openings on the lower side, always near Cyrtophora egg cases. There is also very small second species parasite.

Pemphis forms a bonsai-like carpet across the terrace closest to the sea. Behind that you will see the plants of strand zone 1, especially Scaevola. Notice the size of the Pemphis here (also at Saluglula Pools).

The back of the cave. The water there is over your head. There are cracks and
fissures leading right through the island .... Lost Pond is also part of the water lens.

The top of a sea cave at the Pagat coastline was blown out by Typhoon Yuri.
This photo was taken not long after the event, when the freshly exposed limestone 
was still white. Now it has weathered and is nearly as gray as the old surfaces. The
part on the right is a bridge (full of cracks -- stay off it!). The hole leads down to a
dangerous little channel called the "washing machine".

Do not climb down to the water. The surf can be dangerous!!  Here's what it looks like down there on a calm day:--

Much of the northern coast of Guam has eroding reef known as cut benches.
(You may get a look at these if your reef walk goes to Saluglula Pools.) Crabs
scuttle about on the seaweed as waves wash over them . . . but they have ten
legs with which to grasp the weed.

Revised 7/15/00.  Author & webmaster Dr. Chris Lobban