Some 50 "Dead Zones" in Oceans, Researchers Say

The latest findings, analyzed by Drs. Jane Lubchenco of Oregon State University and Harold A. Mooney and Peter M. Vitousek of Stanford University, show a "disturbing negative trend in the Earth's ability to maintain the quality of human life," Lubchenco stated.

Lubchenco presented the findings at the XVI International Botanical Congress where more than 4,000 scientists from 100 countries are meeting to discuss the latest research on plants for human survival and improved quality of life. Among the findings are:

• Close to half of the land surface of the planet has been transformed by humans, such as filling in wetlands, converting tall grass prairies into cornfields, or converting forests into urban areas.

• Humans have more than doubled the amount of available nitrogen in the environment because of excess fertilizer use and burning of fossil fuel.

• Rates of extinction are 100 to 1000 times what they would be without human-induced changes in the planet. On land, this is largely caused by habitat loss and species invasions that are crowding out native species. In water, this is caused by overfishing, as well.

• The year 1998 was Earth's hottest on record, as human activities continue to increase the concentrations of carbon dioxide and other heat-trapping gases in the atmosphere.

Lubchenco pointed out that while human domination of land masses is clear, the new data also indicates a dramatic alteration of Earth's oceans. There are now some 50 'dead zones' in the world's coastal areas, she reported. The largest in the Western Hemisphere is in the Gulf of Mexico, caused by excess nitrogen and phosphorus flowing down the Mississippi River.

"We've long thought of oceans as having an infinite ability to provide food and other goods and services to humans. But the massive human-wrought changes in our oceans are impairing their ability to function as we assume they will," stated Lubchenco, who is a Distinguished Professor of Zoology at Oregon State University.

"We're degrading the water, changing our coastlines, filling in our estuaries, and changing our rivers," Lubchenco said. "And we're witnessing many signals of the problems that will result from these changes, including toxic algal blooms, coral bleaching and sudden disappearance of fish from key fisheries."

• Half of the mangrove forests, which serve as estuaries in the tropics, have been lost to a combination of coastal development and conversion to aquaculture.

• Global aquaculture now accounts for more than one-quarter of all fish consumed by humans. In the case of shrimp and salmon -- the fastest growing segment of aquaculture -- two to three pounds of fish are needed to grow one pound of the raised seafood. Thus this practice is depleting the oceans of food for wild fish, birds, and marine mammals.

• About 3000 species of marine life are in transit in ballast water of ships around the world, resulting in a serious invasion of non-native species in our waterways. A minor but increasing contributor to the problem is escape of non-native fish and plants from aquariums.

According to Lubchenco, the global-scale changes that we have set in motion will impair the Earth's ability to provide a wide range of services to human life.

"In addition to the direct services of food, fiber, shelter, and medicines, many other inter-dependent services are being disrupted," Lubchenco stated. For example, forests, grassland and coral reefs contribute to flood control and climate regulation. Mangroves, estuaries, coral reefs, and kelp forests protect shores from erosion and provide nursery areas or spawning habitat for economically important species.

Massive changes in the Earth's environment have far-reaching implications that result in conflicts across political boundaries, Lubchenco said. "Scarce resources such as water or fishing rights lead to battles between states and nations. Environmental degradation resulting in food shortages lead to civil unrest and migration into neighboring countries," Lubchenco explained.

Increasing economic inequities in the world raise a host of new issues, according to the researcher. "Inhabitants of poorer nations are less able to buy supplies such as bottled water if the water is polluted, less able to influence important policy decisions such as the choice of a site for a toxic waste dump," Lubchenco said.

The groundbreaking 1997 work of Lubchenco and her colleagues documented that we now live on a human-dominated planet, with the growth of the human population and the amount of resources used are altering Earth in unprecedented ways. Her current analysis updates these findings. "The dramatic rise in our population simply exacerbates the problems," Lubchenco stated, noting that as of July 17, 1999, there are reportedly six billion people on Earth, a doubling in less than 40 years.

Lubchenco did see hopeful signs in the increasing number of people who are concerned about the environment and are willing to take action. She noted that "it is encouraging that there is an increasing focus on the part of the private sector, religious groups, and individual citizens to take responsibility and undertake innovative action."

"As inhabitants of earth, we need to take stock of these massive changes, understand their implications, and change our direction, " Lubchenco said. "We are currently inattentive stewards. It is in our best interests to be more fully engaged in ensuring our own health, prosperity and well-being."