Inside Sea Science
9/22/2006 6:20:35 PM by Stacy Wynn
The sheer size of our oceans is unfathomable. But it's the scientific discoveries lurking underneath that'll really get you thinking.
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The oceans cover 71 percent of our planet, yet remain one of the last virtually unexplored frontiers on Earth. According to the Smithsonian, if mined, all the gold suspended in the world's seawater would result in nine pounds for every person on our planet. If the oceans' combined salt content were dried and spread out over the continents, it would cover them to a depth of five feet. An underwater waterfall beneath the Denmark Strait drops over two miles; that's over 3.5 times the drop of Venezuela's famed Angel Falls, the tallest waterfall on land. Ninety percent of all volcanic activity occurs in the oceans. It's no wonder the study of this magnificent aquatic mass has inspired dreams, literature, the arts and science since the beginning of mankind.
Underwater Medical Cures
Fascinating as boating upon the sea is, the world beneath is extremely strange and complex, yet in some ways parallels our world on land. It's those differences and similarities that fascinate marine scientists known as "bioprospectors," who search the billions of undersea lifeforms to discover the valuable chemical compounds they may produce, which could be used in modern medicine. Marine ecosystems contain an estimated 80 percent of the plant and animal species on the planet, and over the past decade alone, 5,000-plus new compounds have been discovered.
The National Cancer Institute believes that around 65 percent of all cancer drugs are derived from natural products. Medicines from ocean life are one of the most hopeful new directions of the multi-billion dollar medical research field. "Discodermolide" is an agent harvested from deep-sea sponges that has shown itself to be a successful killer of cancer cells, even Taxol-resistant tumors. Taxol is presently one of the leading treatments for breast and ovarian cancers.
A leader in scouring the sea for potential cures is the Harbor Branch Oceanographic Institution (HBOI) Division of Biomedical Marine Research (DBMR). The institution's research submersibles from Johnson Sea-Link allow scientists to seek out previously undiscovered deep sea creatures and microorganisms which may hold a potential cure for human disease. The scientists are also examining previously catalogued sea life that warrants further study.
"We've only begun to realize the possibilities for new drug discoveries in the ocean. It's like the rainforests, where plants and animals that could hold the keys to new drugs are becoming extinct every day. We have the same potential in the oceans, the least-explored and understood environments in the world," says Dr. Peter McCarthy, DBMR senior research scientist.
Sea life that remains in a given location is of significant interest to marine scientists. These organisms conform to their environment to the level, if they are to survive, that some develop toxic chemicals to repel their natural predators in their localized environment. Sometimes the decision on where to search next is just an educated guess from some extremely knowledgeable minds. The organisms in question tend to be found on hard bottoms, including reefs, where there are plenty of corals, sponges, algae, mossy bryozoans and tunicates (think sea squirts).
For more than 20 years, HBOI scientists have covered the globe. Searches have ranged through the Caribbean and eastern Atlantic to the Canary Islands, Cape Verde and western Africa. In the Pacific Ocean, the focus has been on the Galapagos Islands, Papau New Guinea, Samoa and Australia. The Indian Ocean has shown much promise around Thailand and the Seychelles.
A Common Marine Organism With Uncommon Uses
The common Limulus polyphemus, or Horseshoe Crab, is found in the western Atlantic from Maine on down to the Yucatan Peninsula, with a huge population in Delaware Bay. This 100 million-year-old life-form touches us in ways we may be unaware of. The crab's blood contains a unique clotting factor that can be used to detect bacteria in human blood. As a bonus, the clotting factor can be removed from the blood of horseshoe crabs without hurting them. A polymer found in the crab's shell, called Chitin, is now utilized to create non-allergenic sutures and wound-healing bandages. Nobel Prize-winning research into the crab's oversized compound eye and its optical nerve has aided research into the human eye.
Though they've been around from before the time of dinosaurs, horseshoe crab populations are declining. The University of Delaware Sea Grant College Program has funded Dr. Nancy Targett, marine biologist and Graduate College of Marine Studies associate dean, to minimize fishing pressure on the crab population. To that end, Dr. Targett and her graduate student, Kirstin Ferrari, have isolated the substance in horseshoe crabs that makes them attractive to conch and eels, and therefore attractive to conch and eel fisherman as a handy source of bait for their intended targets. The compound is now being turned into an artificial bait and being tested by fisherman.
"Our goal is to develop an artificial horseshoe crab bait that will work as well as the traditional one," she says. "The result should be a win-win situation for fishermen and the horseshoe crab, resulting in more horseshoe crabs for spawning and sustainable uses in medicine."
Is the Ocean the World's Largest Air Purifier?
In 2004, French and Australian scientists did a landmark study of the Antarctic waters south of Australia to calculate how much of the dangerous greenhouse gases the ocean can potentially absorb and store, conceivably for centuries or longer. Professor Alain Poisson from the University of Paris and Dr. Bronte Tilbrook from Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) headed the research teams.
"The Southern Ocean is vital for controlling the concentration of carbon dioxide in the atmosphere," says Dr. Tilbrook. "This project is helping us obtain a much clearer picture of the interaction between ecosystems and mixing that drives the carbon dioxide exchange between the ocean and atmosphere. The results show the oceans store about 48 percent of fossil fuel emissions and more than 50 percent of that accumulation takes place in the Southern Hemisphere."
Additionally, a significant portion of the carbon dioxide deposits in the ocean are in the Southern Hemisphere in the sub-Antarctic region off the continent's southern shores. The deep Antarctic ocean water starts off with low carbon concentrations. This water upwells then circulates north, where it turns into surface water that can absorb anthropogenic carbon dioxide during its travels. Once back in the sub-Antarctic region, the waters again become dense enough to sink below the surface and carry the anthropogenic carbon dioxide away from contact with the atmosphere. The model has been compared to a giant conveyor belt that naturally increases the ocean's tendency to absorb and store carbon dioxide.
Professor Alain Poisson, from the University of Paris, who has been studying the Southern Ocean for over a decade, says, "It's essential to learn the evolution of the oceans and atmosphere. This area is crucial because if something happens here it will react on the global climate."
So it seems the ocean's role in all of our lives is something that should not be taken lightly. Only time will tell what new discoveries and potential cures the ocean will yield. In the meantime, scientists have an enormous watery canvas to work on, and the rest of us can just sit and watch the sunset, maybe getting inspired to write a poem or two.