Arctic & Antarctica
Processes in the biological pump. Credit: Nature Communications

More than just whale food: Krill's influence on carbon dioxide and global climate

Antarctic krill are well-known for their role at the base of the Southern Ocean food web, where they're food for marine predators such as seals, penguins and whales.

Less well-known is their importance to the ocean's carbon sink, where CO2 is removed from the atmosphere during photosynthesis by phytoplankton and sequestered to the seafloor through a range of processes.

A new study published in the journal Nature Communications has highlighted the influence of krill in the carbon cycle and urged consideration of the impact of commercial krill fishing on ocean chemistry and the global climate.

Led by Dr. Emma Cavan, a former IMAS researcher now at Imperial College London, the study reviewed current scientific knowledge of the role of krill in processes that each year remove up to 12 billion tonnes of carbon from Earth's atmosphere.

"By eating phytoplankton and excreting carbon and nutrient-rich pellets that sink to the seafloor, Antarctic krill are an integral part of the carbon cycle and a key contributor of iron and other nutrients that fertilize the ocean," Dr. Cavan said.

"Krill fecal pellets constitute the majority of sinking carbon particles that scientists have identified in both shallow and deep waters in the Southern Ocean.

Read linked article.

Explore further. Krill behaviour takes carbon to the ocean depths

More information: E. L. Cavan, et al. The importance of Antarctic krill in biogeochemical cycles. Nature Communications volume 10, Article number: 4742 (2019). DOI: 10.1038/s41467-019-12668-7.

https://www.nature.com/articles/s41467-019-12668-7#Abs1Journal information: Nature Communications