Coral Reefs Scenario
Below is the article "Reef Disease: Alarming Increase" that appeared in the April/May 1998 issue of National Wildlife (Vol. 36, Num. 3).

ou don't need to be a scientist to have a fairly good idea of what these diseases do to coral reefs: white pox, rapid wasting disease, patchy necrosis, white plague or black-band disease. Those are among more than a dozen known infections that attack coral tissue or skeleton and that are increasing at an alarming rate in some areas.  Last fall, researchers from an Environmental Protection Agency monitoring program announced that disease on Florida's coral reefs increased by a whopping 292 percent from 1996 to 1997. Not only has the number of coral species with ailments grown, so has the number of diseases, including some that are new to science. "We are really stunned at what we found," says ecologist James W. Porter of the University of Georgia. "There is no precedent for what has happened in the past year."  Corals, which are animals, carry in their tissues symbiotic algae that allow the hosts to produce more oxygen than they consume.

That productivity is crucial to the overall health of coral reefs, which support a wealth of fishes and other sea life.  Scientists think that changes in the ecosystem have made corals increasingly susceptible to scourges that have long existed in ocean waters. Also discovered last year were sick fishes swimming on the reefs, including some with red spots similar to the lesions caused by recent outbreaks of the microbe Pfiesteria  along the mid-Atlantic seaboard. Among the causes theorized for the reefs' ailing health are poor water quality and polluted or disease-bearing runoff from land into Florida Bay.  Florida is not alone. The first global survey of coral-reef health, called Reef Check, recently found that about 95 percent of the world's coral reefs have been damaged by over-fishing, dynamiting, poisoning, pollution or ships' anchors.  "The results are very shocking," says study coordinator and marine biologist Gregor Hodgson of Hong Kong University of Science and Technology.

Below is a map produced by digitizing maps and presenting them in uniform formats. The coral reefs are represented in red. (Source - ReefBase by the World Conservation Monitoring Centre in Cambridge, UK)

Coral reefs comprise some of the greatest areas of biodiversity on Earth, rivaling the biodiversity of the rain forests. Like the tropical rain forests, coral reefs are found only in the tropical and semitropical areas of the world where water temperatures range from 16șC to 30șC. Generally coral reefs are found within 30° latitude of the equator.

The current coral reefs resulted from production that occurred over the past five to ten thousand  years. The actual coral makes up only a small part of the life found on the reefs but  provides habitat for numerous other species. Coral reefs play an important role in providing a food source and a living for many people, especially in developing nations such as the Philippines and the Dominican Republic. Anticancer drugs and painkillers have been developed from coral reef products. Research is now being done on a method to encourage bone growth in humans by mimicking the coral secretions. Additionally, coral reefs play an important role in biogeochemical cycles, especially the carbon cycle. 

In recent years, some deterioration of known coral reefs has been noted. Some experts suggest that ten percent of Earth's coral reefs have already been destroyed and that another sixty percent is in danger. There are dissenting opinions because of the narrow surveying of reefs. Uncertainty exists since only reefs close to population centers have been thoroughly surveyed. Some causes of the destruction are obvious, like when Philippine fishermen dynamite and inject cyanide into reefs, for example. Other causes are more difficult to pinpoint. In addition to the human influences of destruction, there are also natural influences to be considered.  

The National Oceanic and Atmospheric Administration (NOAA) is concerned that injured or destroyed marine habitats may indirectly upset the ecological balance and the world's food chain. The question then arises: even if coral reefs are being destroyed at an alarming rate, why should we be concerned?   After all, the current coral reefs are only 5,000 to 10,000 years old. 

Situation
An international team of coral reef scientists speaking at the International Tropical Marine Ecosystems Management Symposium conference at Australia's Great Barrier Reef reported that ocean conditions in 1998 have affected almost all species of corals, leading to unprecedented global coral bleaching and mortality. A major outcome of the symposium was the establishment of the International Coral Reef Initiative (ICRI) to stop and reverse the global degradation of coral reefs and associated ecosystems. 

ICRI and NASA's Earth Science Enterprise (ESE) have approached your team of Earth Systems scientists for a thorough evaluation of all the factors affecting coral reef survival. ESE and ICRI are particularly interested in your team's recommendations regarding how to deal with the situation. 

Assignments
Over the next two weeks (Week A and Week B) you will work individually and in teams to address the coral reef situation. Use the links below to access your assignments.

Week A: Teacher as Problem Solver
Private Theory Rubric
Individually, identify what you believe to be true and the reasons why you have those beliefs regarding coral reefs.

Week A: Teacher as Problem Solver
Knowledge-Building Rubric
As a team, build ESS knowledge about the coral reefs event described in the scenario, and develop a problem statement.

Week B: Teacher as Model Builder
Model-Building Rubric
Using your team's original or revised problem statement, build an ESS model that includes the ESS relationship statements and evidence that support your conclusions (recommendations or solutions).

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