How does sulfur move from land ecosystems into the ocean?

Sulfur moves from land ecosystems into the ocean primarily through two pathways:

• Runoff: A continuous loss of sulfur occurs in terrestrial ecosystems as it drains from soil into lakes and streams, eventually reaching the ocean as runoff.1
• Atmospheric Fallout: Sulfur is also transported to the ocean through fallout from the atmosphere. This occurs when sulfur compounds, such as those released by the weathering of rocks or human activities like fossil fuel combustion, are deposited onto the Earth's surface or precipitated out in rain and snow.12

Once in the ocean, sulfur cycles through marine communities, reenters the atmosphere, or is sequestered in marine sediments.1