As rising global temperatures continue to melt more Arctic sea ice, nitrogen is expected to play a bigger role in supporting organisms in regions never thought possible.
What’s happening?
In a recent study first published in the journal Communications Earth & Environment, a team of researchers from the University of Copenhagen took a closer look at nitrogen fixation, a process in which bacteria convert atmospheric nitrogen gas into usable fuel for algae growth. They uncovered a remarkable discovery that could have a substantial impact on the planet.
The persistent loss of Arctic sea ice is increasing nitrogen fixation, which could trigger blooming algae in the Arctic Ocean. Not only would this support the Arctic marine food web, but it could also potentially increase the Arctic’s capacity to absorb carbon dioxide. This could ultimately play a positive role in fighting future global temperature rise.
Why is an increase in nitrogen fixation in the Arctic Ocean important?
The study was led by Lisa W. von Friesen, a postdoctoral researcher in marine ecology at the University of Copenhagen. She offered valuable insights into her team’s findings and explained why the discovery of nitrogen fixation under melting Arctic sea ice came as a surprise.
“Until now, it was believed that nitrogen fixation could not take place under the sea ice because it was assumed that the living conditions for the organisms that perform nitrogen fixation were too poor. We were wrong,” von Friesen said in a news release.
As the melting of Arctic sea ice continues, more algal blooms may be produced in the coming years. The non-cyanobacterial diazotrophs that feed on dissolved organic matter produced by these algae can then release fixed nitrogen, especially along the edges of ice sheets. This can create a symbiotic relationship that has the potential to support an even more robust marine food web.
“In other words, the amount of available nitrogen in the Arctic Ocean has likely been underestimated, both today and for future projections. This could mean that the potential for algae production has also been underestimated as climate change continues to reduce the sea ice cover,” added von Friesen.
What’s being done about predicting future global conditions?
Despite the potential benefits, the increased rates of nitrogen fixation under melting Arctic sea ice could also create some uncertainty for researchers. Now equipped with a more detailed understanding of nitrogen fixation, climate researchers will likely need to adjust future climate models for more accurate predictions of the changing conditions in and around the Arctic.
“For the climate and the environment, this is likely good news. If algae production increases, the Arctic Ocean will absorb more CO2 because more CO2 will be bound in algae biomass,” said Lasse Riemann, biology professor at the University of Copenhagen and senior author of the study. “But biological systems are very complex, so it is hard to make firm predictions, because other mechanisms may pull in the opposite direction.”
Currently, rising global temperatures have been linked to more frequent and intense extreme weather events. Warmer temperatures have also led to rising sea levels, threatening coastal communities around the globe.
“We do not yet know whether the net effect will be beneficial for the climate. But it is clear that we should include an important process such as nitrogen fixation in the equation when we try to predict what will happen to the Arctic Ocean in the coming decades as sea ice declines,” added Riemann.
��
Get TCD’s free newsletters for easy tips to save more, waste less, and make smarter choices — and earn up to $5,000 toward clean upgrades in TCD’s exclusive Rewards Club.
