Sea-ice loss disrupts Arctic Ocean ecosystems and biogeochemistry

A new perspective review published in the scientific journal Nature Climate Change on the ecological and biogeochemical implications of the loss of Arctic sea-ice highlights the need for the production of new research knowledge to support global climate modelling and decision making.

Better understanding on the implications of diminishing sea-ice is vital for improving global climate models and their representation of the global carbon cycle as well as for the management of the Arctic environment and its natural resources.

Arctic sea-ice loss affects the climate and ecosystems

The decline of Arctic sea-ice is occurring much faster than anticipated and research on the ecological consequences is still mostly inconclusive. It is very likely that diminishing sea-ice will cause a decrease in biodiversity and will profoundly alter the functioning of ecosystems. Sea-ice is a significant component of the climate system, but its biogeochemical dynamics are not sufficiently included in the current global climate models.

“The rapid transformation of the sea-ice scape will result in disruption across almost all aspects of Arctic chemistry and life and we are only just beginning to understand how profound, complex and diverse the consequences will be”, states lead author of the paper, Professor Delphine Lannuzel from the Australian University of Tasmania Institute of Marine and Antarctic Studies.

International research on Arctic sea-ice changes

Senior research scientists Letizia Tedesco and Hermanni Kaartokallio from the SYKE Marine Research Centre contributed largely to the paper. In particular, Tedesco led the section on “Environmental conditions” while Kaartokallio contributed to the section on “Biota”.

Tedesco is a specialist in polar marine ecosystems and biogeochemical modelling and a member of the steering committee of the international sea-ice researcher network BEPSII (Biogeochemical Exchange Processes at the Sea-Ice Interfaces).

“We review current knowledge and understanding of the impacts of the changing Arctic sea-ice environment on biogeochemical cycles and associated biota. However, our attempt is not quantitative”, says Tedesco. “We urge for the production of new and sustained long-term field data and improved models to reduce uncertainties and foster predictive capabilities”, she continues. “Sea-ice biogeochemistry is still not described in most of the large-scale Arctic models and in Earth System Models in particular. There is an urgent need for new modelling studies that can address the role of sea-ice biogeochemistry in the Earth system. This holistic approach will allow the science community to deliver firmer predictions on how the Arctic system is responding to the Great Arctic Thaw”, she concludes.

”Based on available research, sea-ice loss is anticipated to result in disruption across Arctic Ocean food webs from bacteria and planktonic algae to top predators such as whales and polar bears”, notes Kaartokallio. “Likely changes in ecosystem productivity will also affect biogeochemistry, including material flow between the surface of the ocean and the seafloor as well as the flows of climate-relevant gases across the sea-atmosphere boundary. Eventually, species endemic to the Arctic, such as beluga whales, polar bears and polar cod, will decline as their habitat dwindles and will be replaced by sub-polar species better adapted to the new conditions, with consequences on the functioning of the entire food web still unknown.”

The research included over 30 researchers from Finland, Australia, the Netherlands, Norway, Germany, Belgium, Canada, the USA, the UK, Japan, France and South Africa.

Figure: Future expectations of changes in the sea-ice biogeochemical system in the Arctic (JPG)

More information

  • Senior research scientist Letizia Tedesco, Finnish Environment Institute, tel. +358 295 251 686 firstname.lastname@ymparisto.fi
  • Senior research scientist Hermanni Kaartokallio, Finnish Environment Institute, tel. +358 295 251 247, firstname.lastname@ymparisto.fi

Links

Sea-ice loss disrupts Arctic Ocean ecosystems and biogeochemistry (News, 2 November 2020, SYKE)