Arari River

The Arari River (Portuguese: Rio Arari) is a river of Marajó, an island in the Amazon Delta. It is in the state Pará in northern Brazil. The river starts south of Lake Arari and flows through swampy areas called mondongos. These areas often flood during the wet season.

After passing Cachoeira do Arari, the river becomes straighter. The water looks dark and muddy because of aninga plants. Near Marajó Bay, the river widens and its banks become rocky. Many lakes line the river, especially in the middle and lower parts.

The Arari River connects to the Marajó-Açu River through a stream called Furo das Laranjeiras. Sometimes, depending on the water level in Marajó Bay, the river can flow in the opposite direction. This change affects oxygen levels, temperature, acidity, turbidity, water quality, and the Trophic State Index.

People use the land along the river for large water buffalo farms. Small farmers use the river for daily needs, growing crops, and fishing. Fish from the Arari River, like Tamoatá fish, are sold in the Ver-o-Peso market in Belém.