Warming Arctic Could Disrupt Global Nitrogen Cycle
The study, published in the journal Nature Communications, showed that sensitive areas in the Arctic plays a larger role in the global nitrogen cycle as previously thought. Despite accounting to only one percent of the world's continental shelf, Arctic accounts for about five percent of the global ocean nitrogen removal.
"The role of this region is critically important to understand as humans put more nitrogen into the ocean via fertilizers, sewage and other sources," explained Amber Hardison, an assistant professor of marine science at The University of Texas at Austin and co-author of the study, in a statement. "The Arctic is also undergoing dramatic changes linked to climate change, including a rapid decline in sea ice. As sea ice shrinks, it disrupts the natural functioning of the ecosystem, including potentially limiting the vital nitrogen removal process."
For the study, the researchers measured different processes that can remove nitrogen in the Chukchi Sea, a part of the Arctic Ocean adjacent to the Pacific Ocean and Alaska. The researchers found that the shrinking sea ice in the Arctic could negatively influence bacteria involved in the denitrification process.
The depleting sea ice could alter several marine ecosystems, including animals living in and on the seafloor, in not yet known ways. These animals, such as worms and clams, make tubes and burrows in the seabed, creating a prefect space for bacteria to engage in denitrification. The global nitrogen cycle has been well maintained by the oceans in the past. However, increase human activities, causing fertilizer and sewage runoff into the oceans, have tilted the balance. Nitrogen is essential for the survival of all living things. But excessive nitrogen can harm both marine and terrestrial ecosystems. Large concentration of nitrogen could promote the growth of algae that are harmful to marine life.
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