Mamberamo River

The Mamberamo River is a massive and vital waterway in Indonesia.

It is located in the province of Papua on the island of New Guinea. This river is the second longest on the island after the Sepik River. It is also the second largest river in Oceania by discharge volume. In Indonesia, it ranks as the second largest river by volume. It is also the widest river in the entire country. The river serves as a major artery for a region filled with incredible life.

The river begins at the confluence of two upper tributaries. These are the Tariku and Taritatu Rivers. They meet in the Lakes Plains region. This area is an interior basin. It contains extensive freshwater swamp forests and grasslands. From there, the Mamberamo flows northwards. It travels between the Van Rees Range and the Foja Mountains. The water moves through a series of rapids and deep gorges. The final 160 km of the river are navigable by boats. Near the coast, the river forms a broad delta with many marshes.

The geology of the Mamberamo region is quite young. It dates back to the middle to late Miocene. This means the area is less than 15 million years old. Because it is young, the region remains tectonically active. This activity causes frequent earthquakes. Landslides also occur often in the steepest areas. The river system is a "white-water" system. This means the rivers are rich in sediment. This is similar to the Amazonian moors. The landscape is shaped by dynamic river meanders. These curves continually modify the land. Some banks erode rapidly. Other banks grow as new sediments accumulate.

The Mamberamo Basin is a major biodiversity hotspot. It contains both Asian and Australo-Pacific botanical elements. There are many different types of forests here. These include swamp forests and lakeside forests. There are also sago forests, which are dominated by the sago palm. Other types include primeval forest, secondary forest, and mixed forest. Montane forests and damar forests also exist. The Foya Mountains are a globally outstanding repository of biodiversity. A recent biological assessment found many new species. This included the first new bird species from New Guinea in 60 years. Scientists also found new plants, frogs, and invertebrates.

Many unique animals live within this massive catchment. Crocodiles are common in the rivers. These include the freshwater species, Crocodylus novaeguineae, and the saltwater species, Crocodylus porosus. The globally endangered Scott's kangaroo lives in the Foja Mountains. You can also find the northern cassowary and the Victoria-crowned dove. Other notable animals include the black-spotted couscous and the dwarf opossum. The rediscovery of the endemic Berlepsch's bird of paradise is also noteworthy. The area is also home to the giant rat and a bow-fingered gecko.

Human history in the region involves early explorers and modern concerns. In 1545, the Spanish navigator Iñigo Ortiz de Retes sailed the northern coast. He charted the river mouth as San Agustín. He claimed the territory for the Spanish Crown. He also gave the island the name Nueva Guinea. Much later, in 1883, the Dutchman Dr. D. F. van Braam Morris entered the mouth. He wanted to see if steamships could navigate the river. In the 1990s, the Indonesian Government planned a large hydroelectric dam. This dam would have submerged much of the area. The plan was shelved after the financial crisis of 1998 to 1999. Environmental groups still worry the plan might return.

Today, the Mamberamo remains a very special natural system. It is the second largest river in the world that is completely unfragmented by dams. This means the water flows freely through its catchment. This is similar to the nearby Fly River. Most people living in the area have low population densities. They live from subsistence activities. This includes hunting, fishing, and small-scale agriculture. They grow sweet potatoes, manioc, bananas, and coconuts. They also trade goods like dried fish and crocodile skins. The river remains a wild and powerful force in the world.