Pantanal

In the rainy months, rivers grow big and spill over.

Water covers the flat land like a giant puddle. Animals move to the dry, high spots. When the dry months come, the water slowly goes away.

The Pantanal is a giant seasonal floodplain. Britannica explains that in the summer rainy season, from about November to March, the rivers overflow their banks and flood the lowlands, forming shallow lakes, swamps and marshes. Only higher patches of ground stay dry, like islands.

In the drier winter season, from about April to September, the rivers pull back, though some low land stays wet. The floods leave behind mud that makes the soil very fertile. UNESCO adds that during floods many large mammals move to higher ground, and during severe droughts the wetland can be the only damp place in the region.

Britannica describes the annual cycle: during the summer rainy season (November-March) rivers overflow into the lowlands, forming shallow lakes and countless marshes around islandlike high ground; in the drier winter (April-September) they withdraw, leaving the lowlands only partly drained. Studies also point to a network of underground streams that moves water below the surface. Flood-borne sediments make the soils fertile. UNESCO's statement places the main flooding between October and April, followed by a slow retreat that leaves many temporary lakes.

This flood pulse drives the ecosystem. UNESCO notes that rivers spread nutrients across the basin and let fish move between river systems while young; large mammals retreat to higher ground in floods, and in severe droughts the plain may be the only humid area. The Pantanal is also shaped by its neighbors, sharing species with the Cerrado and Amazon and with the Chaco and Atlantic Forest regions.

People raise cattle on big ranches in the Pantanal.

Boats travel along its rivers. In very dry years, fires can burn the grass and trees, and fire is a big danger to the wetland.

Britannica says thousands of acres of ranch land support cattle, making the region one of Brazil's biggest sources of beef. Its rivers are used for transport, and the wetland cleans water and helps refill water stored underground.

The Pantanal also faces problems. In 2020, a severe drought dried out much of the wetland, and huge wildfires burned parts of it, including the Encontro das Águas park, where many jaguars live. UNESCO lists dredging, overfishing, cutting forests, erosion, pollution and dams as serious threats.

Britannica notes that the Pantanal is one of Brazil's largest sources of beef, with extensive cattle ranching, and that it purifies water, discharges and recharges groundwater, provides waterways for transport and plays a role in climate stabilization. By the late 20th century, gold mining and farming around it and poaching and tourism within it threatened its ecology.

UNESCO calls the region highly fragile and lists dredging, excessive fishing, deforestation, acute erosion, wastewater and waste, dams that change water flows, and the canalization of rivers as serious threats, with Pantanal Matogrossense National Park and the Dorochê reserve directly affected. In 2020, the Copernicus program reported severe drought and wildfires across the Pantanal, with Encontro das Águas among the worst-hit reserves and a large number of jaguars affected.

Many visitors explore the Pantanal by boat.

Wear a life jacket and stay with a grown-up and a guide. Watch the animals from far away. Never feed them.

Much of the Pantanal is water, so a visit may include a boat ride with a local guide. Watch caimans, capybaras and jaguars from a distance, keep your hands inside the boat and never feed wild animals.

On the water, the US Centers for Disease Control and Prevention (CDC) says life jackets lower the risk of drowning for people of all ages, so wear one on every boat ride. Bring water, a hat and sun protection, and follow park rules. In dry seasons, never light fires: drought and fire are among the Pantanal's biggest dangers.

Many trips include travel by boat, and the region's large wild animals, including jaguars, caimans and anacondas, should be watched only from a distance and with a guide. The CDC states that life jackets reduce drowning risk for people of all ages and swimming abilities and that children should wear them around natural water.

Responsible tourism matters here. Britannica names poaching and tourism within the wetland among historical pressures, and the 2020 fires reported by Copernicus show how dangerous dry-season fire can be. Choosing licensed guides, keeping to permitted areas, never feeding or approaching animals and never lighting fires help protect a landscape UNESCO calls highly fragile.