Part 3. Brazil's Remote Cristalino River

Forrest M. Mims III

Editor's Note: The author's research for NASA in Brazil's Amazon basin in 1995 was described in three previous columns (see Part 1 , 2 and 3 ). This is the third installment of a series about expanded research in Brazil during 1997.

The last installment ended with Brad White and me stuffing our backpacks with science instruments and water bottles. We were preparing for a field trip to the remote Cristalino River.

After a bumpy, dusty ride of an hour or so, our guide dropped us on the shady bank of a large river. A few hours later, a boat arrived with half a dozen bird watchers. Their guide explained the ambivalent attitude Brazilians have about burning down their rain forest. He said that those doing the burning view themselves as good citizens who are clearing a non-productive wasteland to provide space for new pastures and crops. The tourist industry despises the burning. The smoke drives away tourists and the burning is destroying what tourists want to see.

Brad and I said goodbye to the bird watchers and climbed into the boat, which soon headed off into the smoke toward a tributary named the Cristalino River. Having seen only muddy brown and tea-black rivers in Brazil, I was looking forward to seeing this crystal clear river.

Finally our boat turned into the tree-lined Cristalino. It was the clearest black river I had ever seen. You could see at least two centimeters through its tea-colored water.

The Floresta Amazonica in Alta Floresta has a jungle lodge on the remote Cristalino. There are several one-room bungalows, a meeting room, dining area, and kitchen. As Brad and I walked up to our bungalow in an isolated clearing, two foxes wandered off into the dense forest. We spent the next several days making measurements in the rain forest.

One day I wanted to climb a big hill in the jungle. So Brad and I hopped in a canoe, which one of the guides in a motor boat towed a few miles up river. He then angled us toward the mud bank, pointed toward the jungle and loosed our rope (Fig. 1).

"Muita fumaca," he said. Much smoke. He then roared away.

Brad and I managed to find a trail to the top of the hill. There I made a full range of sun and sky measurements, while both of us were tormented by squadrons of sweat bees (Fig. 2). Between measuring the ozone layer, the atmosphere's optical depth, and various other parameters, we would stop for a while so I could sweep my insect net back and forth and capture hundreds of the sweat bees. This bought enough time for the next set of measurements until reinforcements buzzed in.

One of my big goals was to swim in the Cristalino. But that was before it revealed itself to be a black river. Black river or not, one afternoon I decided to go for a swim. So I walked out on a floating dock and dove in.

Somewhere between the dock and the water, I remembered the schools of piranhas, the vicious caimans and the deadly parasites waiting below. I dove out as fast as I dove in. But it was a warm afternoon. Since none of the feared creatures managed to take a bite out of me, I dove in and dove out several more times.

One evening after supper, Brad and I spotted a pair of bright orange eyes glowing near the river bank a hundred yards away. We decided to cruise over in a canoe for a closer view. I had a flashlight, so I was in front. Brad guided from the rear as we paddled.

As we neared our quarry, shrubs overhanging the water blocked both our view and the way. Oblivious to the spiders and wasps that probably lived there, we pressed on. Suddenly the flashlight revealed what was behind those eyes. It was a huge alligator-like creature called a caiman.

The caiman's big head was lying at the edge of the water. The rest of the creature was sprawled out on the bank. At the time he appeared to be at least as long as our canoe. In retrospect, he was probably a bit shorter.

Since Brad was still hung up in the limbs at the back of the canoe, he didn't't see the caiman. He kept pushing forward.

"Brad," I whispered. "Stop."

He didn't't hear me. He just kept on pushing branches away while trying to paddle forward

"Brad, we have to stop." I quietly insisted. "Now!"

Just as I thought the caiman might lunge at the canoe, Brad spotted the giant. It was impossible to turn around. So we backed out through the tangle of branches as quietly as possible.

One day three bird watchers arrived. One was a guide from Australia, who I'll call Jim. He was a compassionate man, for the fellow bird watcher he was guiding was a paraplegic.

It was strange to see a man in a wheelchair with binoculars glued to his face being pushed along trails in such a remote rain forest. It was admirable to see Jim carry his client to a boat and carefully deposit him in his wheel chair. The third bird watcher was an Englishman, who walked around telling his tape recorder about the birds he had seen.

This was pretty funny. When I mentioned it to Brad, he slyly replied that I did the same thing while doing sun and sky measurements.
Brad was right. I developed a new respect for the Englishman and his tape recorder. But we were soon to lose our respect for the Australian.

To be continued.

Forrest M. Mims III and his science are featured online at www.forrestmims.org .

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise , Seguin, Texas. The column is written for a general audience.

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