GalapagosQuest: Nature Notes

Christina swims like a fish      RELATED VIDEO Real 28K      MORE REPORTS Day 20:End of a Journey Day 19:Nature Notes Day 18:Our Connection ... Day 17:The real final frontier Day 16:Islands in Danger? Day 15:Forests at the Edge Day 14:Swimming with Day 13:Hellos and Goodbyes Day 12:Journey to the heart Day 11:Learning in a pinch Day 10:Gringo Guides Day 9:Survival Issues Day 8:Gross,Warty.. Day 7:Water Scarcity Day 6:Should I have... Day 5:Arrival and Survival Day 4:The Hood Mockingbird Day 3:Lethal Charm Day 2:Flames in the Ocean Day 1:Off to a Bad Start

March 25, 1999
Web posted at: 5:47 p.m. EST (2247 GMT)

By Christina Allen

(Classroom Connect) -- All my life, I thought I was a good swimmer. "A fish," they called me when I was young. Then I swam with a sea lion, a spotted eagle ray, and a shark. They put me to shame. Even a red-lipped batfish is more graceful in the water than I am.

Nonetheless, today I entered a fish's world. At "Cousin's Rock," I descended a 180-foot rock wall into the blue depths. Flipping backward out of the dinghy, I held my mask on my face and my regulator in my mouth. Compressed air in the tank allowed me to breathe, my wetsuit kept me warm, my weight-belt helped me sink, and a buoyancy compensator that fills with air helped me return to the surface.

At about 10 feet deep, my ears started to hurt from the pressure. At sea level, we're under one "atmosphere" of pressure, about 15 pounds per square inch. But at 33 feet in the water, the pressure doubles. It's called "Boyle's Law." To "equalize" the pressure inside and outside of my head, I held my nose and blew, adding air from my throat to my sinus cavities. Ahh, relief.

Once my ears cleared, strange sounds erupted all around me. I could hear the snapping sound of a tiny crustacean which stuns it's microscopic prey with the snap of a claw, the waves lapping on a distant shore, my own breathing through the regulator and several sounds I can't even identify. Sound travels about four times faster in water than in air. This is how divers and other sea creatures can hear sounds produced very far away. Some whales, for example, can communicate from thousands of miles away. Could that be a whale I've been hearing?

At 40 feet I started feeling cold. I check my thermometer. Eighty degrees. That's odd, I think to myself. I wouldn't be cold if it were 80 degrees on the surface. Turns out that water draws, or "conducts" heat away from your body much faster than air. Water is a better conductor of heat because it has more direct contact with your skin as it flows around you.

These spotted eagle rays look like flying carpets when they swim

I forgot about the cold when I saw, approaching out of the murky distance, large dark shapes. First two, then 10, then 20 or more. They appeared in formation like a squadron of flying carpets. As they neared, I could make out their white underbellies and dark, speckled tops. A huge group of spotted eagle rays! I kicked my fins, and the next thing I knew, I was right in their midst! Together, we glided through the water, as if flying. Just then the low-air alarm on my air gauge went off, beeping madly. It annoyed me that with all our technology we still haven't overcome our most basic limitations.

I couldn't even go straight to the surface, but had to come up slowly to avoid getting the "bends." When we are under increased pressure in deep water, we absorb more air (mostly nitrogen with a little oxygen) into our blood. As we come up, these gasses expand and are returned to the lungs to be released as we breathe. But if we go up too fast, the nitrogen can expand too fast form bubbles and get trapped in our joints. The bends is very painful and can even kill if you're not careful.

Back on shore, I thought about my incredible undersea adventure. I had read that the seas are being overfished, with some fishermen using nets 80 miles long. Factories dump toxic waste, and many cities flush their sewage right into the ocean. Moreover, 58% of the world's coral reefs are threatened. It occurred to me that if the people doing all these terrible things to the sea could spend 15 minutes swimming with eagle rays, much of the destruction would stop.

There is a bright spot. President Clinton just passed legislation to increase protection of Coral reefs. And here on the Galapagos, just last week, officials passed a plan, which extends the no-fishing zone to 40 miles beyond the islands and provides more money to patrol the waters for illegal activities, like poaching whales. As a testimony to this, about 50 feet from our boat is a huge fishing boat from Panama that was confiscated for illegally fishing with drift nets. When the boat was stopped by patrols, it had an enormous net surrounding a huge school of tuna and two whale sharks, which were freed.

Let's face it. We'll never be completely comfortable in a fish's environment. But at least we can help preserve it so they will be.

Making Waves,

Christina

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.