THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Tuesday, April 11, 1995 TAG: 9504110004
SECTION: FRONT PAGE: A12 EDITION: FINAL
TYPE: Another View
SOURCE: By CHERYL ANN BUTMAN and JAMES T. CARLTON
LENGTH: Medium: 84 lines
When people think of this planet's biological treasures, they tend to think of things that live on land: the creatures of the rain forest, the animals of the African plain, the abundant crops of the mid-latitudes. But the biological resources of the sea - the coral reefs, the great schools of fish, the exotic deep-sea communities - also are critically important to humans and in many ways are even more at risk.
All around the world, fisheries and shell fisheries are collapsing due to overfishing and disease. Many of the great fishing areas like the Georges Bank off the coast of New England, which was once thought to be ``inexhaustible,'' are on the verge of extinction or have been closed. The Chesapeake Bay once contained enough oysters, which strain water through their gills, to filter the entire estuary once a week. Now the oysters of the Bay filter the water at best once a year.
Coral reefs around the Caribbean islands, Hawaii and parts of Australia are dying. Sedimentation from logging and land development, physical alteration and destruction of the reefs, and the overfishing of predators that keep reef communities in balance are destroying ecosystems that, in terms of biodiversity, are the marine equivalent of tropical rain forests.
More than 90 percent of the original wetlands in California have been filled or developed, as have about three-quarters of the wetlands in Maryland and Connecticut. The result has been habitat loss, coastal erosion and decline in water quality.
On any given day, an estimated 3,000 species of organisms are traveling in the ballast tanks of ocean-going vessels. When those organisms are discharged into new water, they can completely alter existing ecosystems.
By releasing carbon dioxide and other gases into the atmosphere, humans may be raising the Earth's temperature. Increases in water temperature could harm marine life directly and could alter ocean circulation, which would affect the supply of nutrients needed to sustain marine life. And if destruction of the ozone layer leads to higher levels of ultraviolet radiation, many marine organisms could suffer.
These ongoing changes to the marine environment will have far-reaching consequences. We rely on the oceans for much more than food. Marine organisms also supply us with biomedical products and modify the flow of chemical compounds among the oceans, atmosphere and land. They are part of a unique and irreplaceable natural setting, one that always has had a special appeal to humans.
Marine ecologists and oceanographers need to know much more about life in the ocean to predict how human activities will affect marine organisms. But today the processes that influence marine biodiversity are largely unknown. Even in familiar habitats like coral reefs and temperate bays, vast numbers of species never have been identified or studied, and their roles in the overall ecosystem remain obscure.
The situation is even worse in less-familiar habitats. In places like the deep sea or polar oceans, each expedition to a new area turns up hundreds of previously unknown species. Marine biologists also are discovering organisms living in unexpected places, such as whale carcasses that sink to the ocean floor. In fact, these carcasses may serve as steppingstones for organisms traveling between deep-sea hydrothermal vents.
If the oceans are to act as a sustainable, long-term resource for humans, we must know much more about marine ecosystems. New tools are now available for exploration of large regions of water and the ocean floor, and new laboratory techniques can identify unique organisms and reveal the relationships among them. The stage is set for studying the ocean in ways impossible to imagine a decade ago.
What is needed now is research on marine biodiversity that links specific studies with broader issues that are relevant to society. Such studies would tie local, smaller phenomena to larger oceanographic patterns and processes. In turn, policy-makers would receive critical information for wise management of ocean resources. With better understanding, we could conserve and preserve the diversity of life in the sea.
Many marine ecosystems are hidden from view. But they are a mainstay of human existence, and we neglect them at our peril. MEMO: Ms. Butman is an associate scientist in the applied ocean physics and
engineering department at the Woods Hole Oceanographic Institution in
Massachusetts. Mr. Carlton is professor of marine sciences at Williams
College-Mystic Seaport in Connecticut.
by CNB