For decades, scientists have asserted that the leakage of warm, salty Indian Ocean water south of South Africa into the Atlantic is a major contribution to the Atlantic Meridional Overturning Circulation (AMOC), a component of the global ocean conveyor system. New research led by an international team from the Netherlands, USA, China and UK suggests that the mechanism linking leakage of Indian Ocean water and deep-water formation was and is not as straightforward as previously thought. This research contributes to a better understanding of the AMOC, a key regulator of the Earth’s climate.

More than 100 shallow lakes along the Atlantic coast of southern Brazil and Uruguay could become one of the world’s most important natural laboratories for tracking climate change and human impact on freshwater ecosystems. An international research team has identified this overlooked subtropical lake network as a global hotspot for monitoring biodiversity, water quality and ecosystem resilience. This was published in the open-access, peer-reviewed journal One Ecosystem.

Risso’s dolphins around the British Isles are part of a single population – genetically distinct from those elsewhere in the Atlantic, new research shows.

The EU project SYNCHRONY will launch on August 1st, 2026. It aims to contribute to a better understanding of the rapid changes taking place in the complex system comprising the ocean, ice and atmosphere in the Southern Ocean and around the Antarctic ice shelves, as well as their impacts on the global climate and biodiversity. Led by the Alfred Wegener Institute, researchers from a total of 27 global partner institutions from around the world will work in interdisciplinary work packages to optimise and expand the existing observing system, harmonise data streams, and create new data products that document the state of the climate system and biodiversity. The project thus also provides an important foundation for the international UN Ocean Decade initiative Antarctica InSync and builds on existing research consortia. The EU will fund SYNCHRONY with around 8.5 million euros over the next four years.

Permafrost in the Arctic stores large quantities of organic carbon. When the frozen ground thaws or coastal sections erode, this carbon can enter the sea, where microorganisms can break it down and convert it into climate-damaging greenhouse gases. The extent to which this carbon actually enters the atmosphere, however, and how much remains in the ocean has hardly been quantified to date. Researchers from the Alfred Wegener Institute and MARUM – Centre for Marine Environmental Sciences at the University of Bremen have now been able to answer this question for the first time for the permafrost coast of Qikiqtaruk (Herschel Island) in Canada. With the help of sediment cores, they discovered that considerable amounts of terrestrial carbon are stored in the seabed. It also became apparent that microorganisms are particular gourmets who decidedly prefer fresh marine carbon. The researchers published their findings in the journal Nature Geoscience.

Calcium isotopes in fossilized shells show ocean acidification caused the extinction event. Massive volcanic eruptions released CO2 into the atmosphere, acidifying seawater. Fifth Northwestern study to link volcanic eruptions to ocean acidification and extinction. Ancient events help scientists understand current CO2 increases and potential consequences.

With the growing demand for marine exploration and environmental monitoring, underwater sensing technology faces severe challenges due to high humidity and the need for simultaneous detection of multiple physical parameters, such as temperature and pressure. Traditional underwater sensors typically rely on combinations of various functional materials to achieve dual-mode temperature–pressure detection, often requiring additional waterproof encapsulation, which complicates system integration. Achieving dual-mode temperature–pressure detection within a single material underwater remains particularly challenging. Herein, a waterproof dual-mode sensor based on Bi₂Se₃/carbon paper (CP) composite films is developed by electrochemically depositing pyramid-interface-structured Bi₂Se₃ layers on both sides of a flexible CP substrate. The film exhibits enhanced thermoelectric properties, with a power factor of 106.0 μW m⁻¹ K⁻² (9 times that of CP). Sensors constructed from vertically stacked pyramid-interface-structured films enable high-precision detection of temperature and pressure underwater, featuring a temperature-sensing response time of 0.9 s and a pressure sensitivity of 0.94% kPa⁻¹, while allowing synchronous decoupling of the two signals. Moreover, the sensor exhibits excellent hydrophobicity, with a contact angle of 143.7°, along with robust stability, overcoming key limitations for underwater applications. This advance in flexible underwater sensing technology offers a reliable strategy for underwater human–machine interaction and monitoring.

Ports are typically highly polluted environments, which makes it imperative to find new ways to clean them up. Here, scientists studied five species of common Mediterranean sea sponges to see whether they can function as ‘ecosystem engineers’ for filtering water and nature restoration. One tested species, commonly called the ‘chicken kidney sponge’ proved especially hardy when transplanted to a busy polluted recreational port near Girona, Spain. Under these challenging conditions, it typically thrived to the point where it could reproduce asexually into dispersing clones. The authors intend to use this species in further long-term renaturalization trials.