Satellite view of the Amapa mangroves, on the northeast coast of Brazil Photograph by USGS   Northern South America: Northern Brazil Mangroves   600 square miles (1,600 square kilometers) -- about half the size of Rhode Island Relatively Stable/Intact

· A World Sprung from Mud
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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A World Sprung from Mud

The mangroves of the Amapa ecoregion in Brazil can be found where flooded grasslands, savannas, and tropical rainforests converge. Colonies of mangrove trees emerge from the hundreds of islands and mudflats that form as the Amazon River deposits large quantities of fine-grained clay and sediment. These colonies thrive because they are frequently flooded in downpours of rain, and their roots are washed by the fresh water of the most extensive river system in the world.

Special Features

If you were to look closely at the root system of a mangrove forest, it might seem as though the trees were walking on water or mud. As the Amazon drains into the Amapa River, it deposits large quantities of fine-grained clay and sediment, creating a mud so thick that air cannot pass through it. Because the roots cannot get oxygen from deep within the mud, the mangroves have evolved aerial roots that protrude from the mud and the surrounding water’s surface like spider legs. If you were to walk next to these spindly roots, you would notice a peculiar stench, a bit like rotten eggs, rising from the mud. The strange smell comes as your footsteps release the gases that are produced by the decomposition of organic material trapped beneath the mud’s surface. You must be careful while walking here too, because the thick layers of sediment can be sticky enough to suck the boots right off your feet!

Mangrove seedlings are great travelers, designed to create new tree colonies wherever they settle. When it is ready, a seedling falls like an arrow from the tree. In low tide it will land in the mud and put down roots immediately. If it is high tide it will fall into the water and float until it finds a place to grow roots, sometimes traveling as long as a year before it has a chance to settle and sprout.

Wild Side

Traveling by boat through the mangrove swamps of Amapa provides an opportunity to see some remarkable species. In the lacework of roots along the shore, you might see oysters, assorted mollusks, and sponges that have attached themselves to the tidal region at the spindly feet of the trees. Higher up in the branches, a loud whooping cry might be a sign of passing of howler monkeys. You might also see the endangered scarlet ibis, whose brilliant plumage stands out in stark contrast to the mudflats, as the bird digs its long, curved beak into the sediment-laden waters in search of the shrimp that help give it its vivid coloring.

Cause for Concern

The low population density and relative inaccessibility of this region have helped to protect it somewhat, although the abundance of crabs living in the shallow waters at the base of mangroves has led to heavy harvesting by fishermen. If this practice is not managed properly, it could threaten certain species. Mangrove trees are cut down and used in the construction of homes and boats, and the bark provides tannin used to dye ship sails and preserve fishing nets.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.