Small marine crustaceans, like krill, are just as essential for carbon storage as major coastal habitats and should receive equal protection, according to recent research.
Recent research highlights that tiny marine crustaceans are as crucial for carbon storage as important coastal ecosystems and must be protected in a similar way.
The research indicates that Antarctic krill, a single species, sequester comparable amounts of carbon to significant ‘blue carbon’ environments such as mangroves, salt marshes, and seagrasses.
However, krill are threatened by global warming and possible overfishing, suggesting they should be given the same protective measures as other vital habitats, according to the research team.
In the Southern Ocean surrounding Antarctica, krill serve as food for larger animals like whales, seals, and penguins, yet they are also harvested for human consumption, bait, aquaculture, and dietary supplements.
Dr. Emma Cavan, the lead author from Imperial College London’s Department of Life Sciences, expressed, “For the last ten years, we have been discovering the role krill play in carbon cycling, ultimately leading to this astonishing conclusion that krill and their waste store as much carbon as several coastal marine plants.”
“This finding opens the door to protecting krill and their critical ecosystem in the Southern Ocean just as diligently as we protect seagrasses and mangroves.”
This study was published in Nature Communications and involved researchers from Imperial College London alongside experts from the University of Exeter, the UK Centre for Ecology & Hydrology, the British Antarctic Survey, Plymouth Marine Laboratory, and the Technical University of Denmark.
Co-author Dr. Simeon Hill from the British Antarctic Survey stated, “This research illustrates how humans are interconnected with a small creature in a distant region. We benefit from krill in carbon removal, yet our actions that contribute to climate change also affect them.”
Significant Importance
Marine organisms are vital in sequestering carbon from the atmosphere in ocean ecosystems, and the term ‘blue carbon’ was introduced over a decade ago to signify the critical part coastal marine vegetation plays in this process.
Nevertheless, the ocean has alternative methods to store carbon beyond the coastlines, including through animals such as krill. Despite being small (about 6cm), krill are abundant crustaceans residing in Antarctic waters.
They feed on phytoplankton, which are tiny plants that absorb carbon from the air during photosynthesis. When krill defecate or shed their exoskeletons, the carbon they’ve ingested sinks into the deep ocean, where it can be captured for extended periods.
The new study reveals that Antarctic krill sequester at least 20 million tonnes of carbon annually into the deep ocean, valued between $4 billion and $46 billion, depending on carbon pricing.
Co-author Professor Angus Atkinson from the Plymouth Marine Laboratory remarked, “Antarctic krill are renowned for being central to the unique Southern Ocean ecosystem and supporting a crucial fishery. However, this research presents another important perspective on krill — their significant role in carbon storage.”
The Impact of Krill
Krill’s effectiveness in carbon storage is attributed to their massive populations, which can swarm in numbers up to 30 trillion, producing large, quickly sinking fecal pellets and other waste.
Dr. Anna Belcher, a co-author from the UK Centre for Ecology & Hydrology, added, “One fascinating aspect of krill is their capability to form enormous swarms, sometimes extending over a kilometer. This leads to a substantial ‘rain’ of krill waste post-feeding, making krill globally significant for sequestering carbon. We need to prioritize the protection of these remarkable crustaceans!”
The research also found that the depths required for these waste products to be securely stored for at least 100 years are surprisingly shallow (an average of 381 meters), further elevating their potential. Collectively, these factors indicate that krill’s carbon storage capabilities are comparable to those of coastal blue carbon plant ecosystems.
As Antarctic krill face the impacts of rapid climate change and are increasingly targeted by fisheries, the researchers advocate for the protection of both krill populations and their habitats to maintain this crucial carbon reservoir. Highlighting the ecosystem’s value in terms of carbon storage underscores the importance of achieving climate objectives and integrating carbon considerations into conservation strategies.
