Polluted Dust Impacts Tropical Pacific Oxygen Levels

Map showing how air pollution depositing iron in the northern Pacific Ocean can travel thousands of miles. (Credit: Georgia Institute of Technology)

Scientists at the Georgia Institute of Technology have uncovered how the movement of polluted dust can impact life in the world’s oceans, according to a release. They have used a modeling approach to chart how polluted air originating in East Asia can waft over the Pacific Ocean and create conditions that ultimately impact dissolved oxygen levels in tropical ocean waters far away.

The models showed that air pollution from the region, containing high levels of iron and nitrogen, is carried away by winds and ocean currents and then consumed by photosynthesizing phytoplankton. This consumption, though it adds oxygen to the atmosphere, actually has a negative effect on oxygen levels in the deep ocean.

More active photosynthesis in the surface, researchers say, produces more organic matter that sinks down deeper into the ocean. As it does this, bacteria consume it along with oxygen that depletes oxygen levels. The process plays out all across the Pacific Ocean, but its impacts are more pronounced in tropical zones.

Top image: Map showing how air pollution depositing iron in the northern Pacific Ocean can travel thousands of miles. (Credit: Georgia Institute of Technology)