Underwater Exploration

Future exploration of the oceans of the world parallels our exploration of outer space in many ways. To increase understanding of both, technologies are being merged in creative ways. In the Arctic Ocean Basin, a submarine and sophisticated acoustics are combined to measure water temperature. The U.S.S. Hawkbill, a nuclear attack submarine operated by the U.S. Navy, launches acoustical probes that measure the density, salt content, and temperature of seawater along the path of the sound. The Hawkbill is part of a research platform for SCICEX 99, the fifth year of a working relationship between the Navy, the National Science Foundation, and other federal departments interested in the relationship among the atmosphere, oceans, and climate. The acoustic tests performed by the Hawkbill show that, after shrinking for four years running, the Arctic ice cap may be building again; the pattern of shrinkage and growth enters into our understanding of the importance of the ice cap.

Exciting underwater finds like the discovery of the Titanic have led to a burst of shipwreck hunts. The Titanic adventure proved that the technology exists to find any lost vessel anywhere, and all parties from historians to gold grabbers are looking for Spanish galleons, passenger liners, Roman vessels, and historic ships for their cargo and the answer to questions about their fate. Ethical and legal questions have arisen over control of shipwrecks; apart from monetary value, their contents are historically and scientifically important. The United Nations Economic, Scientific, and Cultural Organization (UNESCO) has drafted a treaty establishing the limits of a nation's cultural underwater heritage offshore, which may help regulate the hot underwater marketplace. Even television rights for photographing discovered wrecks is highly contested.

Similarly, the underwater riches that occur naturally as mineral deposits are being mined at shallow depths, but the rights for deep sea minerals are contested. The "black smokers" or hydrothermal vents in the Mid-Atlantic and other rift zones belch minerals like smoke, but these minerals include gold, lead, and silver. Undersea craters off the coast of Japan were discovered in 1998 and are thought to have over $2 billion in mineral riches on and near them. Deep-sea submersibles are an expensive ($1 million per month at sea) but available tool for harvesting the minerals, but these vents also support exotic life forms, including tube worms, anemones, and giant clams that are not found in any other Earth environment. Just as archaeologists are contesting shipwreck hunters over historical disasters, marine biologists are trying to compete with the mining industry in preserving nature's secret treasure trove.

Pure observation to further our knowledge of the underwater world is also progressing, thanks to technology. Off shore near New Jersey, the Long-Term Ecosystem Observatory has been constructed to record a battery of measurements of physical, chemical, and biological state of the sea. Complex instrument packages along with instrument-bearing torpedoes and surface vessels transmit, collect, and convert a variety of signals into information about the ocean. An underwater habitat named Aquarius is sited off the Florida coast about 60 ft (20 m) under water. Aquanauts including Sylvia Earle are studying coral reefs that indicate the health of near-shore waters but also the deep ocean. The Monterey Bay Aquarium uses two remotely operated vehicles (ROVs) for similar purposes of probing the characteristics and life forms in the deep canyon under the Monterey (California) Bay.

Despite the huge technological leap into deep waters in the past century, there are other creative ways of exploring underwater. A team from the Smithsonian Institution is using natural enemies to its advantage. To attempt to film giant squid in their natural environment, the Smithsonian is using a "crittercam," a video camera attached to an animal to pursue and film this elusive creature. The sperm whale preys on the giant squid, and, using a suction cup to mount a small video camera on the whale's back, scientists hope to obtain candid shots of the squid. The whales are not expected to return the camera for processing; instead, the camera films for three hours, then releases the suction on the cup, and floats to the surface.

Similarly, scientists at McMurdo Station, Antarctica have attached cameras to Weddell seals to study the ecology of fishes living beneath the sea ice. In this case, wild seals are captured and fitted with photographic and other sensing equipment. The seals are taken to an isolated area of sea ice with no natural breathing holes. A hole is drilled into the ice and the seals are allowed to hunt freely. Because there are no other options, the seals must return to the artificial hole for breathing. The equipment allows the scientists to monitor the activities of the seals and environment in which they and their prey exist. Once the information is collected, the equipment is removed from the seal and it is released at the location it was captured.