Unveiling the Secrets of the Deep-Sea Ecosystem: A 500,000-Year Study in the Southern Ocean
The study co-led by Professor Moriaki Yasuhara, Ms Raine Chong, and Dr May Huang has provided valuable insights into the evolution of the deep-sea ecosystem in the Southern Ocean over the past 500,000 years. Published in the journal Current Biology, the research reveals the significant impact of temperature changes and food input on shaping deep-sea communities.
Despite the stable deep-sea temperature, organisms in this environment are highly sensitive to even minor fluctuations. With no sunlight reaching the deep sea, primary production is absent, and organisms rely on marine snow – organic material that descends from the ocean surface. This includes dead plankton, a crucial food source for deep-sea organisms.
By analyzing deep-sea fossils from sediment cores spanning half a million years, the research team demonstrated how temperature and food input have influenced deep-sea communities over long time scales, affecting different species in distinct ways. Professor Yasuhara emphasized the importance of understanding ecosystem dynamics in the face of human-induced climate change.
As concerns over climate warming escalate, efforts are being made to develop geoengineering technologies like ocean-based climate intervention (OBCI) to combat climate change. These technologies, such as marine carbon dioxide removal (mCDR), aim to store carbon in deep-sea sediment to reduce future warming. However, the potential impact of these interventions on deep-sea ecosystems remains a major concern.
Professor Yasuhara highlighted the vulnerability of the deep-sea ecosystem, which covers over 40% of the Earth’s surface and is home to countless undiscovered species. The study’s findings underscore the need for careful ecosystem impact assessments before implementing technologies like mCDR, especially in sensitive regions like the Southern Ocean.
The Southern Ocean, considered a ‘canary in a coal mine’ due to its sensitivity to global climatic changes, requires increased biological monitoring to provide early warning signals. The study also revealed that the present-day deep-sea ecosystem in the Southern Ocean was established 430,000 years ago, raising concerns about potential future alterations due to human-induced warming.
In conclusion, the research sheds light on the delicate balance of the deep-sea ecosystem and the need for cautious decision-making to preserve its integrity in the face of climate change. Ongoing monitoring and research efforts are crucial to safeguard the deep-sea ecosystem and its invaluable biodiversity for future generations.