Photo : Martial Trezzini/Keystone via AP

India's Deep Ocean Mission: Aquanaut reached a record of 5,000 metres 

BIODIVERSITY
Greenland’s melting ice is supercharging life in the sea says NASA
On 15 August, SciTechdaily reported that researchers supported by NASA discovered that glacial runoff near Jakobshavn Glacier lifted nutrient-rich deep waters to the ocean surface. They fueled summer phytoplankton blooms that increased by up to 40 per cent. The findings were based on advanced computer simulations published in Nature Communications, Earth & Environment that modeled interactions between marine life and water movement in a turbulent Greenland fjord. During summer melt seasons, vast quantities of meltwater, originating from Greenland’s rapidly shedding ice sheet rose hundreds of feet beneath the sea surface. It stirred nutrient-dense waters upward. These nutrients, such as iron and nitrate, were vital for boosting phytoplankton growth, the foundation of marine food webs and a key driver of carbon dioxide absorption. The results highlighted how melting ice was shaping ocean productivity. (NASA's Jet Propulsion Laboratory, "Greenland’s Melting Ice Is Supercharging Life in the Sea," SciTechDaily, 15 August 2025) 

Deep-Sea expedition reveals thriving life in Pacific Ocean trenches 
On 31 July, the BBC reported a Chinese-led expedition documented thriving deep-sea life in the northwest Pacific Ocean at depths exceeding nine kilometres. Using the submersible Fendouzhe, the team from the Chinese Academy of Sciences explored more than 2,500 kilometres of ocean trenches between 5,800 metres and 9,533 metres. They filmed beds of clams, mats of bacteria resembling ice, and dense colonies of tube worms up to 30 centimetres long. They also found previously unknown species such as Macellicephaloides grandicirra. The findings, published in Nature, challenged assumptions about survival under extreme pressure and darkness. It showed ecosystems fuelled by methane and hydrogen sulfide drippping from the seabed. Samples were preserved for future analysis to understand chemosynthetic processes and adaptations to high pressure. Scientists described the abundance of life as “amazing” and unprecedented. (Victoria Gill, "'Communities' of strange, extreme life seen for first time in deep ocean," BBC, 31 July 2025) 

CLIMATE CHANGE
Earth records unprecedented ocean heat and sea-level highs 
On 15 August, CBS News reported that a State of the Climate report from the American Meteorological Society found that last year saw record-high global ocean heat and sea level. Also, it faced peaks in global temperature and greenhouse gas concentrations. The year’s climate data revealed that the oceans absorbed extraordinary amounts of heat, triggering extensive marine warming and contributing to sea-level rise. Greenhouse gas concentrations surged to new highs. The findings underscored the accelerating pace of climate change across multiple key indicators. It signaled a clear escalation in planetary heat uptake and water expansion that risked amplifying extreme weather events, coastal flooding, and marine ecosystem disruptions. ("Ocean heat and global sea level hit new records last year, report finds," CBS News, 15 August 2025) 

Sea levels rise longer and faster than realised says Earth.org
On 14 August, earth.com reported that the researchers extended the historical record of Indian Ocean sea levels by 60 years back into the early 1900s using coral core analyses. It said that sea-level rise had begun accelerating around 1959, decades earlier than tide gauges or satellite data had indicated. From the mid-20th century onward, the Indian Ocean’s sea level rose approximately 30 centimetres. It affected nearly 30 per cent of the world’s ocean. Scientists identified a trace of human-driven climate change, aligning the sea-level rise with rising temperatures and rapid glacial melt. The findings signified that oceans had been responding more strongly to human warming than previously understood. (Rodielon Putol, "Sea levels have been rising longer and faster than we realized," Earth.com, 14 August 2025) 

Bryozoans face threats due to ocean warming and acidification 
On 16 August, earth.com reported the study on bryozoans published in Communications Biology by ICM-CSIC researchers. Researchers examined how climate change pushed bryozoans like Myriapora truncate beyond their limits. They studied the species’ response to warming and acidification using natural volcanic vents off Italy’s Ischia, which simulated future ocean conditions. The team discovered that although the animals altered their skeletal structure and maintained relatively stable microbiomes, acidified conditions degraded microbial diversity. Those microbiomes lost key functions related to nutrition, defence, and stress resistance. Ocean warming also worsened the effects. Bryozoan coverage dropped and mortality increased. The findings revealed that morphological flexibility alone was insufficient to offset the combined stress of acidification and warming. (Rodielon Putol, "'Ocean architects’ expose hidden threats of climate change," earth.com, 16 August 2025) 

DEEP-SEA
India's Deep Ocean Mission: Aquanaut reached a record of 5,000 metres
On 15 August, The Times of India reported that India accomplished a landmark deep-sea exploration when aquanauts descended to 5,002 metres aboard the French-built Nautile submersible as part of the deep ocean mission and preparations for "Samudrayaan." The preceding day, a second dive reached 4,025 metres. The dives, carried out by Jatinder Pal Singh and Commander Raju Ramesh. This marked India’s deepest-ever underwater human expeditions under the Indo-French collaborative project. Union Earth Sciences Minister Jitendra Singh celebrated the timing as a symbolic “double conquest,” coinciding with an Indian astronaut’s mission to the International Space Station. The mission aimed to advance human-rated submersibles and underwater resource exploration. It also works with plans to conduct future descents using India’s indigenous Matsya 6000 submersible by approximately December 2027. ("Deep Ocean Mission: Samudrayaan in sight, India takes a 5,002m plunge," The Times of India, 15 August 2025) 

RESEARCH & DEVELOPMENT
UK scientists raise alarm over marine stress from ocean carbon capture 
On 14 August, UK scientists cautioned that ocean-based carbon capture technologies could impose stress on marine life. They also highlighted the need for comprehensive environmental assessments before large-scale deployment. Techniques such as ocean alkalinity enhancement, where alkaline substances are added to seawater to boost Carbon-di-oxide absorption. This showed promise for mitigating climate change, with companies like Ebb Carbon, Planetary Technologies, and Equatic pursuing pilot programs. However, researchers warned that altering ocean chemistry might disrupt marine ecosystems. Possibly it would precipitate pollutants or harm organisms in unpredictable ways. They emphasised that regulatory frameworks had not urge stricter oversight. The scientists advocated combining engineered carbon removal with natural restoration methods. They stressed that while carbon removal was necessary alongside emission reductions, uncertainties about its safety and effectiveness could limit its adoption. (Aniqah Majid, "Ocean carbon capture raises concerns over marine stress, say UK scientists," The Chemical Engineer, 14 August 2025)