A study of Brazil's rhodolith beds revealed extraordinary hidden biodiversity, with evidence of around 1,800 species and many potentially new to science. These little-known seabed habitats may rival coral reefs in biodiversity, support fisheries and potentially act as important carbon sinks.

The #HighSeasTreaty offers a historic chance to protect nearly half the ocean, but success depends on strong science. Scientists are urged to support rapid ratification, guide key decisions and help design effective marine protected areas. @highseasalliance.bsky.social#HighSeasTreaty

For the first time, the Our Ocean Conference is taking place on African soil. #OOC11 in Kenya will put African ocean leadership, coastal communities, and the Western Indian Ocean at the centre of global action. https://ouroceankenya.com #OurOceanKenya #OurOceanConference

When climate hazards stack up, the damage is far worse than any single event would cause. A review on @nature.com documents 2025's most destructive compound events, from the Los Angeles wildfires to deadly floods across North America and Southeast Asia.

🪸 Researchers in Australia successfully mapped thousands of hidden reefs deep through the water column. By providing the first comprehensive data set of these hidden ecosystems, the project arms planners, environmental managers, and Traditional Owners with the info needed to legally protect them.

The #BBNJ Agreement could help fix long-standing weaknesses in high seas fisheries management. By coordinating fragmented efforts and filling governance gaps, authors argue it may strengthen regional fisheries bodies without undermining their mandates.

Tropical cyclones are travelling over rapidly warming waters, and their ability to cool the ocean surface is weaker than once thought. This mismatch means storms may become stronger than climate models currently predict, increasing future risks. https://www.nature.com/articles/s41561-025-01900-3

A fundamental shift occurred around 2009: the Arctic has flipped from being limited by light to being limited by nitrogen. As sea ice retreats, increased plant growth on shallow Arctic shelves is driving far greater loss of nitrate from the water, reshaping the base of the food web.

📢 The third World Ocean Assessment documents a deepening crisis, as climate change, pollution, overfishing and biodiversity loss put ocean systems under severe strain. Its findings demand urgent action, through stronger multilateral cooperation, greater ambition & decisions grounded in science.

🌊 On #WorldOceanDay, we celebrate the incredible ocean processes that regulate our climate and make life on Earth possible. From circulating currents to microscopic plankton—and even 🐟 fish—our ocean plays a huge role in capturing and storing carbon. #BlueCarbon #OceanClimate

Climate-driven changes in thermal habitat play a stronger role in pushing humpback whales into dangerous fishing zones. 🐋 Stopping #IUUFishing is an essential tool to restore ocean health and combat the global climate crisis. #WorldEnvironmentDay #FightIUUFishing

🆕 1,121 new marine species discovered! From a chimaera, to the "Glass Castle" Worm and Carnivorous "Ping-Pong Ball" Sponge, here are the new species discovered on @oceancensus.bsky.social -led expeditions: https://www.vox.com/climate/488948/deep-sea-creatures-photos-ocean-census

In response to #ClimateChange, seabirds are changing in geographic range size rather than body mass, and dispersing longer distances. 4 specific species face a severe, immediate risk of extinction under future warming scenarios. @jorgeavaria.bsky.social

#Antarctica experienced an unprecedented coastal disturbance event in 2025. Record-low seasonal sea ice allowed exceptional iceberg movement, producing the highest seabed scouring ever recorded near the West Antarctic Peninsula, with potential major long-term biodiversity impacts. @bas.ac.uk#Antarctica

🪸 Coral reef restoration is growing across the Western Indian Ocean, but most projects remain small, fragmented and difficult to compare. Stronger regional coordination and long-term monitoring are essential for scaling effective reef recovery. #WorldReefAwarenessDay

🌱 Warming winters are likely to push #mangroves north along the 🇺🇸 Atlantic coast, with ocean currents and storms helping them spread. This shift could alter coastal ecosystem structure and services. https://onlinelibrary.wiley.com/doi/10.1111/gcb.70676 @vubrussel.bsky.social#mangroves

@unep.org and IOC UNESCO are conducting a global survey to better understand how ocean pollution is perceived and addressed across communities worldwide. Your answers will help shape actions you want to see. Submit your answers ➡️ https://bit.ly/3RhDKVS 📷 Naja Bertolt Jensen / Unsplash

Despite documenting ocean decline, political and societal responses remain too slow. Authors call for ocean science to move beyond observation toward active engagement by forging strategic alliances, centring storytelling, and acknowledging the political nature of science. #OceanGovernance

#SeaLevelRise is not just changing coastlines slowly over time. Stronger seasonal swings could dramatically alter how long intertidal ecosystems stay flooded or exposed, potentially pushing many coastal species beyond their tolerance limits. Most affected are the Med, Caribbean and Pacific regions.

From @ec.europa.eu, a new call for tenders. CINEA is funding a €175k study to develop robust certification rules for Blue Carbon ecosystems (tidal marshes & seagrass meadows). 📅 Deadline 27 May 2026

#BiodiversityDay, #WorldFishMigrationDay, and #WorldTurtleDay, celebrated this weekend, are a powerful reminder of ecological connectivity. By moving across borders and biomes, migratory species maintain the balance of our marine world. #IDB2026

"If the heat is too extreme, then they will essentially starve and they'll die." The arrival of a potentially powerful El Nino weather system this year could devastate coral reefs around the world already weakened by back-to-back rounds of bleaching, scientists warn u.afp.com/SRji

Extreme temperatures reshuffle marine ecological landscapes. In the Southern Ocean, phytoplankton are reshaping size structure and productivity with important implications for future carbon cycling. #ClimateChange

Coastal tourism faces a persistent skills gap. @ec.europa.eu CoastalPro provides an interactive environment to transform traditional training into an engaging journey, where learners can progress through levels, collaborate with peers and track achievements via leaderboards and certifications.

22 May is #BiodiversityDay 🌱 Join the global celebration! Let’s build a future where people and planet thrive together🌍 Learn more on the IDB website🔗 www.cbd.int/biodiversity... Explore the events happening near you and online👉 www.cbd.int/biodiversity... #LocalAction #ForNature

A new study by Allen et al. shows just what the New Scientist headline says. That's in fact not unexpected: warming slows #AMOC, and that's what removing aerosol pollution does. 🌊 The paper 👉 iopscience.iop.org/article/10.1... New Scientist 👉 www.newscientist.com/article/2526...

War-related oil pollution could leave long-lasting scars on Middle Eastern marine ecosystems. Coral reefs, mangroves, fisheries and endangered species in the Persian Gulf and Gulf of Oman are the most threatened. https://www.science.org/doi/10.1126/science.aeh6024

Global seabed mapping has reached an important milestone: @seabed2030.bsky.social added five million km2 of seafloor data in a single year, bringing the total mapped ocean floor to 28.7%. While the ocean covers over 70% of the planet, much of its floor remains unmapped.

From seals and coral reefs to sea turtles and sharks, many marine species are facing potential extinction, threatened by #overfishing, pollution and #ClimateChange. On #EndangeredSpeciesDay, here are some of the ocean creatures most in peril: https://coralvita.co/coral-cafe/endangered-sea-animals/

Protecting space for #mangroves expansion can safeguard carbon storage, coastal protection and tourism under future sea level rise. Conservation measures deliver benefits across all sectors, especially for the climate and the economy. https://www.nature.com/articles/s44183-025-00170-1

After the extreme 2023 UK #MarineHeatwave, scientists outline 40 key questions to improve understanding, monitoring and management of marine heatwaves. Coordinated monitoring, improved forecasting, stronger communication and clearer policy frameworks are suggested as solutions. @noc.ac.uk#MarineHeatwave

10 days to go until #BiodiversityDay 2026!🌿 A global moment to celebrate biodiversity and the actions helping protect life on Earth 🌍 Be part of the celebration for nature 💚 🔗 cbd.int/biodiversity... #LocalAction #ForNature #UNBiodiversity #IDB2026

👋 Hello to new and consolidated followers! Let us introduce ourselves. The International Programme on the State of the Ocean (IPSO) brings together science, communications, policy, and legal disciplines to drive ocean solutions.

Changes in ocean circulation can directly affect ice loss. A recent study shows warm deep water in the #SouthernOcean is moving closer to #Antarctica, increasing heat near ice shelves and raising the risk of faster sea-level rise. #ATCM48 #CEP28

There's still a lot of year-to-year variability in patterns of ocean sea surface temperatures, but there's something else clearly happening... Watch the human-caused warming trend evolve over the last 100 years during the month of April (including to 2026). Data from psl.noaa.gov/data/gridded... 🌊

Fishing vessels can lure seabirds with easy food but expose them to deadly bycatch, creating ecological traps. Slow-breeding species such as albatrosses are most at risk. #WorldMigratoryBirdDay https://www.sciencedirect.com/science/article/pii/S0006320725007116

The deep sea makes up 90% of the ocean's living space. It’s home to ancient corals, bioluminescent wonders, and systems that help make life on Earth possible. A healthy deep sea is essential for climate balance and biodiversity. #DeepDay @deepseaconserve.bsky.social#DeepDay

Genomic comparisons show that commercial whaling caused lasting genetic damage to humpback whales. Even as populations recover, reduced genetic diversity may limit their ability to adapt to future environmental change. @gelifes.bsky.social https://www.science.org/doi/10.1126/sciadv.ady7091

Observations suggest #SouthernOcean productivity is declining, but climate models project future increases. This mismatch highlights major gaps in understanding nutrients and ecosystems, limiting confidence in forecasts of carbon cycling and ecosystem change.

Scientists were shocked to find that the Houtman Abrolhos Islands’ coral reefs survived a prolonged extreme heatwave in 2025 virtually unharmed, which may reveal how to protect corals elsewhere

Climate scientists from NIWA and @universityofotago.bsky.social warn that the recent 🇳🇿 marine heatwave is redefining "normal" for the South Pacific. It's the fingerprint of a Super #ElNiño supercharged by a warming planet. Consequences are critical for kelp forests and local fisheries.

Antarctic coastal polynyas (small, recurring areas of open water within sea ice) bury a disproportionate share of Southern Ocean carbon. However, warmer conditions have amplified this process ninefold, expanding polynya area, boosting phytoplankton growth & strengthening the biological carbon pump.

#SeaLevelRise around Africa has accelerated to over 4 mm per year since 2010, with 2023 bringing record highs across large areas. Melting ice is the main driver, raising urgent risks for coastal communities and ecosystems. @umanitobapress.bsky.social#SeaLevelRise

Using observational constraints, a recent study finds the #AMOC is likely to weaken by about 50% by 2100, much more than previously predicted. Scientists have found that "pessimistic" models are actually the most realistic.

Once rare, atmospheric rivers are now hitting #Antarctica more often, bringing extreme warmth and moisture. These events may destabilise glaciers and ice shelves by promoting melt, runoff and rapid ice loss as the climate warms. @timvernimmen.bsky.social#Antarctica

#ElNiño influences Atlantic fisheries across the tropical and South Atlantic through complex atmospheric links that alter rainfall, rivers and upwelling. Impacts vary by region, species and decade, making prediction difficult and requiring monitoring models. @ucm.es @igeociencias.bsky.social#ElNiño

Antarctic Bottom Water is warming, freshening and shrinking as glacial melt and sea ice changes reduce dense water formation. This slowdown of deep ocean circulation is putting many Antarctic penguin species' habitats at risk. #WorldPenguinDay. @antarctic.bsky.social @csiropublishing.bsky.social#WorldPenguinDay

The #AMOC is likely weakening. Observations show a consistent decline along the Atlantic’s western boundary, although eastern regions partly offset this, meaning the overall slowdown may be smaller than it first appears. @miamirosenstiel.bsky.social

The call for abstracts is open for #IMCC8! We welcome global, interdisciplinary, and student-led contributions. Help shape the future of ocean conservation. 🔗 Submit your abstract: conbio.org/mini-sites/i... ⏰ Deadline: 15 May #OceanConservation #MarineScience #SCBMarine @scbmarine.bsky.social

This #EarthDay calls on the global community to unite in accelerating the transition to renewable energy. 🌊 The ocean holds vast, untapped potential. From waves to tides to currents, ocean renewable energy could play a powerful role in addressing #ClimateChange and building a sustainable future.