Aspire Market Guides


Hydrothermal vents spew out metals vital for tiny carbon-storing plants
Hydrothermal vents are a key source of nutrients required by phytoplankton to fix carbon dioxide. Image: Adobe.

Hydrothermal vents deep underwater could be a vital source of metals that reach the surface ocean and fuel the growth of phytoplankton, tiny plants that form the basis of the marine food web and store carbon from the atmosphere.

Critical shortage

The remote Southern Ocean has a critical shortage of iron and manganese, which boost the biological carbon pump, a vital component of the Earth’s carbon cycle. The main source of these nutrients is land dust, and their deficiency within the ocean is suppressing the rate at which phytoplankton use carbon dioxide from the atmosphere which has become trapped in the ocean.

A new study has found that iron and manganese are released within the boiling water spewed from hydrothermal vents and can reach the ocean surface where phytoplankton live. Water samples collected in December 2019 to January 2020 from the surface to the seafloor revealed an underwater plume of iron and manganese-rich water, which could be traced back to a source in the volcanic ridges crossing the Southern Ocean’s floor.

Chemical processes slowly remove the metals from the plume, but state-of-the-art computer simulations allowed researchers to show that it rises to the surface quickly enough to fertilise the Southern Ocean.

Dr Antony Birchill, Marine Biogeochemist at the University of Plymouth and joint lead author says: “To find evidence for a new source of these metal nutrients in the Southern Ocean is very exciting. We already know that hydrothermal systems could be important from studies elsewhere but to find evidence for one deep in one of the most remote places on earth – a place which we also know is important for the biological carbon pump – is a major breakthrough.”

Ocean fertilisation

Understanding the natural sources of these metals is essential for evaluating the impact of proposed climate interventions such as artificial ocean fertilisation.

“To avoid the worst outcomes of climate change, solutions have been proposed to enhance the oceans natural processes that remove carbon dioxide from the atmosphere,” explains Dr Chelsey Baker, Ocean Biogeochemical Model Analyst at the National Oceanography Centre (NOC) and joint lead author.

Hydrothermal vents spew out metals vital for tiny carbon-storing plants
Iron and manganese are released within the boiling water spewed from hydrothermal vents and can reach the ocean surface where phytoplankton live. Image: Adobe.

“One suggestion is to fertilise places like the Southern Ocean with extra iron. However, we don’t fully understand the consequences of this for the ocean’s ecosystem. Knowing the natural sources of metals and how they support the biological carbon pump is crucial when assessing how effective such a direct climate intervention would be.”

The research is part of the NOC-led and NERC funded, Carbon Uptake and Seasonal Traits in Antarctic Remineralisation Depth (CUSTARD) project looking at how marine life influences the uptake and storage of carbon in the Southern Ocean.

News reference

Birchill A,J. et al (2024) Pathways and timescales of Southern Ocean hydrothermal iron and manganese transport, Communications Earth & Environment.



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *