The key ingredients transported by the river are iron and phosphorus.
These elements are all that an organism called a diazotroph needs to capture nitrogen and carbon from the air and transform them into organic solids that then sink to the ocean floor.
Researchers from the United States, Greece and England found that the Amazon carries these elements hundreds of kilometers into the ocean and has an impact on the carbon and nitrogen cycles much farther afield than previously thought.
It is likely that other rivers also help seed carbon sequestering in the world's oceans, wrote senior author Doug Capone of the University of Southern California.
The findings may help scientists find the best places to test seeding the ocean with iron, a controversial practice that some biologists believe could help mitigate climate change.
There are concerns that iron fertilization could harm sea life and potentially lead to increased production of other greenhouse gases, Capone said.