Researchers Call for Greater Protection of Krill Amid Climate Change and Overfishing Threats
A groundbreaking study reveals that Antarctic krill, small marine crustaceans, store similar amounts of carbon as key coastal ecosystems like seagrass, mangroves, and saltmarshes, highlighting their significant role in the global carbon cycle. The research, published in Nature Communications, suggests that krill should be afforded the same conservation measures as these vital “blue carbon” habitats, given their vulnerability to climate change and overfishing.
Antarctic krill play a key role in the Southern Ocean ecosystem, serving as food for whales, seals, and penguins, but they are also harvested for use in food, fishing bait, aquaculture, and dietary supplements. Lead author Dr. Emma Cavan from Imperial College London emphasized the importance of conserving krill, stating, “We hope to work towards conserving krill and their valuable Southern Ocean ecosystem with the same dedication we give to seagrasses and mangroves.”
Krill’s Impact on Carbon Storage
The study, conducted by researchers from Imperial College London, in collaboration with institutions like the University of Exeter and the British Antarctic Survey, found that Antarctic krill lock away over 20 million tonnes of carbon annually in the deep ocean. This storage is equivalent to $4-46 billion, depending on carbon pricing. Krill achieve this by consuming phytoplankton, which absorb carbon dioxide from the atmosphere through photosynthesis. When krill defecate or shed their exoskeletons, the carbon-rich waste sinks into the deep ocean, where it can remain for hundreds of years.
Professor Angus Atkinson from Plymouth Marine Laboratory noted, “Antarctic krill have long been known for their ecological importance, but this study shows their critical role in storing carbon as well.”
Huge Populations Amplify Krill’s Impact
Krill’s ability to store carbon is boosted by their vast numbers, with swarms sometimes consisting of up to 30 trillion individuals. These swarms produce large quantities of fast-sinking faecal pellets, which effectively transport carbon into the deep sea. Dr. Anna Belcher from the UK Centre for Ecology & Hydrology highlighted this phenomenon, saying, “These massive swarms drive a significant ‘rain’ of krill poo, making them globally important for locking carbon away.”
Surprisingly, the study found that krill waste products only need to sink to an average depth of 381 meters to remain locked away for at least 100 years, further enhancing their carbon storage potential.
Call for Protection Amid Threats
The study underscores the urgency of protecting krill populations, which are increasingly threatened by rapid polar climate change and expanding fisheries. As krill populations are vital for carbon storage, their conservation is crucial for meeting global climate goals. Dr. Simeon Hill of the British Antarctic Survey warned that human activities, including climate change and fishing, are affecting krill populations, stressing that this connection must be acknowledged in policy-making.
Researchers are calling for stronger measures to protect krill and their habitats, ensuring they continue to contribute to the ocean’s carbon storage capacity and help in the fight against climate change.
