At 6,400 kilometers, or 4,000 miles, in length, the Amazon River is the second longest river in the world. The fresh water flows through it and into the ocean at an astonishing rate of 209,000 cubic meters per second—more than the next six largest rivers combined.

Yes, the Amazon River is entirely freshwater, and it is the largest source of freshwater discharge in the world. It releases approximately 200,000 cubic meters per second into the Atlantic Ocean, accounting for about 20% of the total global freshwater transport into the sea. The sheer volume of freshwater is so massive that it creates a "freshwater plume" that can extend for hundreds of miles into the salty Atlantic Ocean, visibly changing the color and salinity of the sea long before the coastline is reached. This plume is vital for the ecosystem, as it carries nutrients like phosphorus and nitrogen that trigger massive algae blooms, supporting a diverse range of marine life. Within the river itself, the water is home to unique freshwater species like the Amazon River Dolphin (pink dolphin) and the manatee. While the salinity is near zero in the main river, the "brackish" (semi-salty) water only begins at the very mouth of the river where it meets the tides of the Atlantic. In 2026, the Amazon remains a critical global freshwater resource, though it faces increasing threats from deforestation and climate-driven changes to the seasonal runoff cycles.