Behind Threats to World's Largest Freshwater Wetland

By Anna Brendle
for National Geographic News

January 10, 2003

Covering 50,000 square miles, (140,000 square kilometers) the Pantanal is the world's largest freshwater wetland. Its central tributary is the Paraguay River, which flows through central-western Brazil, eastern Bolivia, and eastern Paraguay, covering an area larger than the size of Greece or the U.S. state of Louisiana.

Capuchin and Howler monkeys, capybaras, toucans, anacondas, caimans, tapirs, endangered jaguars, rare Hyacinthine macaws, and giant river otters in addition to thousands of varieties of butterflies and brightly colored flowers create an inland ecological paradise. But without increased attention and scientific research, all this could be threatened.

National Geographic EXPLORER recently traveled to Brazil to produce a new television documentary, Brazil's Vanishing Cowboys, which examines cattle herders' lives in the Pantanal, particularly as they drive their animals to high ground during each rainy season. Along the way they encounter the hazards of floods, alligators, and jaguars.

To find out more about the Pantanal, the threats to this unique region, and efforts to save it, National Geographic News spoke with Frederick Swarts, director of the Waterland Research Institute and Secretary-General of the World Conference on Preservation and Sustainable Development in the Pantanal. The nonprofit organization is based in Washington. D.C. and Brazil.

I understand that the Pantanal is the world's largest freshwater wetland. What is the importance of this wetland to its surrounding region?

For one, the Pantanal basin provides flood abatement because it acts as sponge. The Pantanal has a regulatory effect on the Paraguay River, extensively reducing and delaying the height of the flood peak and thus reducing the flood risk downstream. Without it, there is the potential for extensive flooding of the Paraguay River and the Parana into which it flows, affecting Brazil, Paraguay and Argentinian communities.

There's also considerable biodiversity, with a great number of bird species, and the Pantanal basin provides biodiversity protection.

Issues of water purification are also important because the river removes heavy metals from mining industries in region.

What are the greatest threats to the Pantanal?

Various hydrological projects pose some of the greatest threats. One proposed project is called Hydrovia. This project, which would require considerable dredging and removal of rock outcroppings, has not been approved. Nonetheless, there is a danger that it is being implemented on a piecemeal basis. River dredging has happened on a smaller scale in the Pantanal, for example. If there's considerable dredging, water flows at deeper depths and more quickly. This could drain the Pantanal, and alter its diverse ecosystems.

Roughly 80 percent of the Pantanal is located in Brazil, and of that, 98 percent is privately owned. Therefore, the Brazilian government is limited in its power to control what happens to that area. In Bolivia and Paraguay, the Pantanal is more protected. But only 10 to 15 percent of the total area lies in Bolivia and 5 to 10 percent in Paraguay.

Another danger has to do with development of the area. Removing trees along the riverbanks causes rivers to fill up with sediments. This results in the creation of new river channels and flooding in new areas. For example, the Taquari River, one of the major tributaries of the Paraguay River, has seen an exponential increase in sedimentation, which many attribute to erosion in the highlands. This has resulted in alteration of the channel with flooding of over 100 farms and displacement of the people in the area.

Other threats include water contamination, including mining byproducts, agrochemicals, sewage and garbage, and loss of biodiversity from various anthropogenic effects such habitat destruction, poaching, over-fishing, and so forth.

The Waterland Research Institute was created to promote the wetland. How does the institute do this?

The Waterland Research Institute holds international conferences to bring in scientists, international government officials, the three major government stakeholders, and officials from the United Nations, and the World Bank, which have projects existing in the Pantanal region. Promoting ecotourism also offers some potential.

How does the institute balance the responsible use of the ecosystem to maintain ecological integrity with the needs of local people?

This is the key issue, since the Pantanal is largely privately owned. The Waterland Research Institute works to ensure that stakeholders are critically informed. We hold meetings with landowners, because they hold personal interests in the area. For example, if someone in the upper area of the tributary does extensive clear cutting, the direction of flowing water could change, causing people to be displaced as a result of extensive sedimentation and flooding on their properties.

Are there lessons we can learn from the Florida Everglades? Is a similar situation occurring in Brazil?

In the Everglades, extensive development works were done, and many areas were dredged and diked. This created a precipitous decline in the Everglades ecosystem, including the decimation of over 90 percent of one legged wading birds. It is now costing billions of dollars to try to restore the Everglades. But the Pantanal currently remains relatively pristine. And it's 10 to 15 times the size of the remaining Everglades, with very few people living there. Unfortunately, populations are expected to double by 2025. The Pantanal could go the same route as the Everglades if extensive work is not done to protect it now.

What is the prognosis for Pantanal? Is its importance gaining recognition and acceptance by South American governments?

I feel quite optimistic. For a long time, the Pantanal was a forgotten area because the Amazon completely overshadowed it as a priority. It wasn't a well known area. Now, the Pantanal is gaining international attention. The Bolivian and Paraguayan governments are making strides to protect the Pantanal in their respective countries. The Brazilian government is concerned and conducting studies of the region.

What are the roles of cowboys, cattle ranchers, and other indigenous people in the region?

Cattle ranching is the number one industry in the Pantanal, but many diverse opinions arise regarding its impact. Some say that cattle ranching has gone on for hundreds of years without degrading the watershed, and the cattle should be allowed to roam free. Others say cattle ranching is changing local species, that many species are disappearing. Some say that if we remove the cattle, grasses will grow taller, and fires could break out during dry season, destroying the entire region. More research needs to be conducted.