Additional Case Studies

Everglades Restoration
Biosphere 2

April, 1999

Miami, Florida

After decades of damming, channelizing, and draining the Everglades of south Florida, the US Army Corps of Engineers is proposing a plan to undo its work and restore the unique wetland region to its natural hydrologic patterns. The $8 billion, 20-year plan was announced in early April 1999 and will be presented to Congress for consideration in early July. Supporters of the plan hail it as the greatest ecosystem restoration project ever attempted in the United States. Skeptics fear that the costly program will accomplish more engineering and complex, unsustainable water management systems and too little actual restoration of this delicate, and disappearing, ecosystem. Meanwhile, the region's population of 6 million people is expected to double in the next 50 years. Restoration now is important because it may be even more difficult later.

Historically the Florida Everglades was a great, slow-flowing river of grass that started where Lake Okechobe overflowed into a broad, flat, marsh full of birds and alligators and ended where the waters flowed into Florida Bay. Winter rains flooded the region, and summer heat dried out shallow grass flats. Seasonal drought cornered fish into small ponds, where the fishing was easy for the millions of egrets, herons, ibises, storks, and other birds that made the Everglades famous.

A growing human population in south Florida couldn't tolerate this seasonal fluctuation of water levels. Flooding threatened cities and farms, so extensive drainage canals were dug to direct more than 1.7 billion gallons of fresh water a day straight to the ocean. Levees and dams were built to protect roads, and irrigation canals carried water away to expanding fruit and vegetable farms. As a consequence the natural Everglades have shrunk to half their original size and dried out, leaving the area susceptible to wildfires in the summer. Ninety percent of historic populations of wading birds have disappeared.

The restoration of the Everglades has been a principal environmental effort of the Clinton administration. The proposed plan, while still under development, will mean rebuilding a great deal of water management infrastructure. Some levees and canals will be removed, and better connections will be made between different regions of the Everglades. New pumps, canals, and reservoirs will capture 80% of the water currently sent out to sea, returning it to the Everglades. Additional urban wastewater treatment plants will clean water coming from Miami and nearby cities, thus further enhancing flow in the marshes while still allowing increased urban water use.

A group of well known ecologists and biologists, including Stuart Pimm, Paul Ehrlich, Gary Meffe, Gordan Orians, Peter Raven, and Edward O. Wilson have called for caution and a thorough scientific review of the plan. They worry that natural flows cannot be restored using the same old management and manipulation methods. However, supporters of the plan argue that the plan is a step in the right direction. Since it has political momentum now, now is the time to get it through Congress. Continuing scientific review and adjustment of strategies may continue once the project gets set in motion. Although it is true that this work will never restore the Everglades to its real natural state, it may be a useful step in restoring habitat for the birds, alligators, and other species that depend on the area for survival.

For further information, see these related sites:

Everglades restoration information from a variety of sources:

South Florida Water Management District page for the Everglades:

Everglades Digital Library

To read more, see

Environmental Science, a Global Concern, Cunningham and Saigo, 5th ed.
Restoration ecology: p. 107-111
Ecosystem management and adaptive management: p. 111-115
Chaos and stability in ecosystems: p. 53

Environmental Science, Enger and Smith, 6th ed.
Is it too late for the Everglades? p. 314-315

Biosphere 2: Creating Another Earth

  In September 1993, eight tired, hungry people emerged from two years of isolation in a high-tech megaterrarium in the desert near Oracle, Arizona. Designed as an ecotechnological model for space exploration and colonization, this bioengineered facility was intended to grow food, cleanse the air, and recirculate and purify water for its eight inhabitants without exchange of materials (including atmospheric gases) with the outside world. Called Biosphere 2 (Biosphere 1 being the earth), the 13,000 square meter (3.15 acres) complex consisted of living quarters and greenhouses containing food crops and small, but photogenic, areas representing deserts, rainforests, savannas, and an ocean.

 Almost from its beginning, Biosphere 2 experienced controversy and problems. By the end of the first year of their mission, the Biospherians reported deteriorating air and water quality. Oxygen concentrations in the air had fallen from 21 percent to 14 percent. This is equivalent to oxygen levels at an elevation of 5300 m (17,500 ft) and was barely sufficient to keep the occupants alive and functioning. At the same time, carbon dioxide concentrations were undergoing large daily and seasonal variations and nitrous oxide (N₂O) in the air had reached mind-numbing levels. In January 1993, fresh air was pumped in to replenish the dome's atmosphere and rescue the inhabitants.

 Subsequent investigations showed that the missing oxygen was being consumed by microbes in the excessively rich soil in which food crops were being grown. At the same time, fresh concrete used in construction was absorbing carbon dioxide released by microbial metabolism. If this carbon dioxide sink hadn't been available, the air would have become unbreathable long before it did. Water systems also became polluted with excess nutrients, degrading aquatic habitats and contaminating drinking water supplies. Species losses were much higher than originally anticipated. Of the 25 introduced vertebrate species, for example, 18 became extinct. All insect pollinators also died, so that most plants were unable to produce seeds and food supplies dwindled to alarming levels. Weedy vines, particularly morning glories (Ipomoea hederacea), flourished in the carbon-rich atmosphere and threatened to choke out more desirable plants. Although the majority of the insects disappeared, ants, cockroaches, and katydids thrived and overran everything. Biosphere 2 cost nearly $200 million to build, with an additional cost of about $1 million per year for fossil fuel energy to keep all the systems running. That averages out to about $25 million per human occupant for the two-year experiment. How much more would it cost to produce a truly balanced ecological system that could maintain life indefinitely? Although the experiment failed to meet its original objectives, it illustrates the value of ecological services provided by the natural world that most of us take for granted. What will we have lost and what might it cost to replace resources and services on which we now depend if we deplete or destroy the natural world? In this chapter, we will examine how ecological economists assign prices and values to natural resources and ecological services.