Mangroves Could Sequester 5 Million Tons of Nitrogen

Why this is here: The study estimates a market valuing nitrogen removal by mangroves at around $10,000 per metric ton, potentially exceeding the value of carbon storage in these ecosystems.

Ziyan Wang and Benoit Thibodeau analyzed mangrove forests worldwide and determined they currently remove roughly 870,000 metric tons of nitrogen pollution each year. Nitrogen enters waterways from sources like agricultural fertilizer and human waste, causing algal blooms and dead zones. The researchers estimate restored and protected mangroves could sequester over 5 million metric tons of nitrogen annually, a service valued at over $8 billion.

They propose a market for “blue nitrogen credits” priced around $10,000 per metric ton. This market could exceed the economic value of carbon storage in these same ecosystems. However, the study notes mangroves can only effectively capture nitrogen up to a certain threshold.

Eutrophication currently impacts areas like the Gulf of Mexico, the Baltic Sea, and the Yellow Sea. Further research needs to determine how to maintain mangrove health as nitrogen levels increase in coastal waters.