Amazon Delta
The Amazon Delta is a vast river delta formed by the Amazon River and the Tocantins River in northern South America. It is located in the Brazilian states of Amapá and Pará and encompasses the Marajó Archipelago, with Marajó Island as its largest island. The main cities located in the vicinity are Belém and Macapá, each with its respective metropolitan area.
It is the largest river delta in the world. It releases one fifth of the total amount of freshwater that is discharged into the earths oceans, into the Atlantic Ocean, with some estimating that equates to 200,000 litres a second. The area has wetlands, streams, lagoons and rich ecosystems and biodiversity. It is a vital area for wildlife, with extensive mangroves in wetland forests, that cover an area of 38,304 km2 of the delta, with 75% of Brazil's mangroves located in the Amazon Delta. 1.5 million people live locally to the Amazon Delta.
The Amazon Delta has a tropical climate with high humidity and high temperatures. It has a wet season with frequent flooding and a dry season where the delta dries out. These seasons shape the environment of the Amazon Delta and the life in it, such as the water buffalo for which Marajó Island is well known, three-toed sloth, capybara, giant anteater, giant otter, jaguar and pink river dolphins.
Due to the vast amounts of sediment and freshwater released by the Amazon, the delta is not a traditional one, for example in shape. The sedimentary environment near the Amazon's mouth has limited subaerial expression, untypical of a river delta. As a result, some people do not describe it as being a delta.
In 2025, approval was given to Petrobras to drill in a location 500km from the mouth of the Amazon River. This decision has raised concerns from environmentalists, with Brazil’s Climate Observatory NGO describing this as being "disastrous from an environmental, climate, and sociobiodiversity perspective”.