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New research highlights the crucial role of Antarctic krill in carbon storage, revealing that these small marine crustaceans can sequester carbon in amounts comparable to essential coastal ecosystems like mangroves, saltmarshes, and seagrasses. The need to protect krill is underscored, particularly as they face threats from climate change and overfishing.
Antarctic krill serve as a vital food source for larger marine species, including whales, seals, and penguins. However, they are also targeted for human consumption, fishing bait, and aquaculture. Dr. Emma Cavan, the lead author of the study published in Nature Communications, emphasized the importance of acknowledging krill’s role in the carbon cycle, stating that their contributions to carbon storage warrant the same degree of conservation efforts as coastal habitats.
The research, which involved collaboration between various institutions, including Imperial College London, the University of Exeter, and the British Antarctic Survey, illustrates the intricate connections between human activity and marine ecosystems. Co-author Dr. Simeon Hill remarked on the relationship between humans and krill, highlighting how industrial activities impact these vital creatures and, consequently, global carbon dynamics.
The Value of Blue Carbon
Marine ecosystems play a pivotal role in capturing carbon dioxide from the atmosphere, a concept referred to as “blue carbon.” While coastal vegetation has been recognized for its carbon-storing capabilities, this study brings attention to the significant contributions of organisms like krill, traditionally overlooked in blue carbon discussions.
Antarctic krill, which measure around 6 cm in length, thrive in the nutrient-rich waters of the Southern Ocean by consuming phytoplankton. Their waste products, including fecal pellets, facilitate a process where absorbed carbon sinks to the ocean floor, potentially storing it for extended periods. The researchers estimate that krill annually sequester a minimum of 20 million tons of carbon, approximating a storage value between $4 billion to $46 billion, depending on market carbon prices.
Professor Angus Atkinson from the Plymouth Marine Laboratory noted the dual significance of krill to ecosystems and fisheries, yet emphasized this study’s focus on their role in carbon sequestration.
Importance of Swarm Dynamics
The large populations of Antarctic krill are fundamental to their effectiveness in carbon storage. These crustaceans can gather in swarms that number up to 30 trillion individuals, leading to significant carbon flux when they excrete waste. Dr. Anna Belcher, a co-author of the study, pointed out the extensive lengths that krill swarms can cover, ultimately producing substantial carbon-capturing waste.
Findings also suggest that the depth at which krill-derived waste products remain sequestered is relatively shallow—averaging 381 meters—further enhancing their carbon storage potential. As the Antarctic region experiences rapid climate shifts and increasing fishing pressures, the researchers argue for the urgent protection of krill populations and their habitats to safeguard this critical carbon sink.
Recognizing the carbon storage capabilities of krill aligns with broader climate objectives and underscores the necessity of integrating carbon considerations into conservation policies.
More information: E. L. Cavan et al, Antarctic krill sequester similar amounts of carbon to key coastal blue carbon habitats, Nature Communications (2024). DOI: 10.1038/s41467-024-52135-6
Source
phys.org