It's a fact that we have have explored and understand more of Outer Space than we do of our own terrestial oceans. This is due to a number of factors, among which is the problem of the tremendous pressure at the deepest depths, and the slow and ponderous descent that will tax the supply of breathing air for any manned submersible. Pressure rises by 650 pounds for every 100 feet of depth and the Abyssal Plains (the true ocean floor) lie at depths between 9,000 - 10,000 feet. A quick calculation will turn up a figure of about 61,750 pounds of pressure. In addition, the Marianas Trench (the deepest trench in the world and therefore, the lowest elevation on Earth) is 35,810 feet below sea level. With almost 7 miles of water above, an object at that depth would experience a pressure of 16,000 pounds per square inch.

In 1960, when the Trieste bathyscape undertook the 5-hour dive to the bottom of the Marianas Trench, they only spent 20 minutes on the ocean floor observing the various lifeforms and floor features before beginning their 3 hour 15 minute ascent. The submersible only seated 2 and to withstand the staggering pressure, it had walls 5 inches thick and weighed 13 tons. However, an exploratory submersible need not be manned to be effective since it can be equipped with camera and lighting equipment. Without the concern of passenger safety, additional remote sensing equipment, propulsion devices and power supply can be fitted onto the vehicle therefore adding to its effectiveness.

My point here is that with our inability to properly explore 71% of our earth's surface, there must be hundreds upon thousands of species yet undiscovered. Some species have been discovered to be so bizarre as to defy our conventional definition of life. A case in hand is the Giant Tube Worm first discovered in 1977...

These huge creatures grow around deep sea hydrothermal vents in the ocean floor which releases hydrogen sulfide gas powered by volcanic heat. The bizarre creatures grow up to eight feet and live in hard, tube-shaped chitin that attach to the rocks. In the photo on the left, you can see the reddish worms protruding out of the pale tubes. These worms derive nourishment from a symbiotic relationship with a certain species of bacteria called chemoautotrophs (chemo = source of energy from chemicals; auto = synthesize their own food; trophs = type of feeding). When scientists first stumbled upon these worms, they were at a loss as to how these creatures were not only surviving, but flourishing without apparent means of sustenance. The worms have no mouth, anus, stomach or intestines! It's basically a bag of bacteria with an aorta and gonads. Closer inspection revealed that the insides of the worms were lined with bacteria that oxidize the hydrogen sulfide gas and convert them into carbohydrates for the worms. In turn, the worms deliver blood which contain hemoglobin that helps the bacteria break down the sulfides. How do the bacteria get in the worms? Well, when the worms are very tiny, they have a primitive mouth and gut through which the bacteria enter. As the worm ages, the mouth and gut disappear, trapping the bacteria inside the worm.

A little less bizarre is the reigning champion for heat endurance on the face of the planet...the Alvinella pompejana or the Pompeii worm. Where the tubeworms stay a safe distance from the 400 degrees centigrade vent water,the Pompeii worm live in dense communities right at the edge of the vents where water can hit or exceed 100 degrees centrigade. These worms have vast colonies of primitive bacteria living on their backs that impregnate and reinforce a compound that the worm secretes, creating a fleecy mane that scientists assume play some part in protecting the worm from the extreme temperature. As a matter of interest, here's a link that allows you have a better 360 degree view of the little critter : http://www.ocean.udel.edu/extreme2002/creatures/pompeiiworm/

Because the worm and the bacteria can survive in such temperatures, they must have enzymes that can handle the temperatures without being cooked as well.These enzymes are generating a great amount of interest for their heat resistant properties and their uses can extend from paper milling, sewagereclamation to food processing and laundry detergents. Ah the great things such little fellas can inspire...

Each year, the ocean turns up a wealth of discoveries that fascinate and excite us with their diversity and potential. As the Giant Tube Worms have demonstrated, we need to expand our minds and accept that life isn't restricted by the need for such mundane elements as oxygen and sunlight and isn't defined by our narrow view of terrestial biology. If conditions dictate that a lifeform should evolve to be a semi-gelatinous mass, a wisp of sentient gas, a crystalline creature that absorbs radiation, or a something equally fantastic, then life will deliver. Scientists frequently look for evidence of water as a determining factor for the possibility of life but why should it be so? What makes us believe that other forms of life would need water at all? If life evolved on a planet with seas of liquid methane, then methane would be a sign of possible life on other planets,wouldn't it? Maybe the sulphuric acid clouds harbor floating worms much like the Pompeii Worms or better yet, these clouds ARE the life forms that have developed consciousness somehow, much like the sentient god-like ocean in the novel, Solaris. What we define as being alive is only life as we know it. That's a pretty good disclaimer for scientific discoveries in the future that might otherwise embarass the scientific geniuses out there but then, that's life isn't it...life as we know it.