Ultramarine: the science of our oceans and waterways

David Boldeman speaks with CSIRO marine biogeochemist Dr Elizabeth Shadwick about one of Australia’s most important long-running ocean climate observation programs, the Southern Ocean Time Series south of Tasmania.Anchored in waters around 4500 metres deep, this remote ocean observatory allows scientists to measure how the Southern Ocean absorbs heat and carbon dioxide from the atmosphere, and how these processes influence the global climate system.Dr Shadwick explains how carbon dioxide moves from the air into the ocean, how physical circulation and deep water formation can store that carbon away from the atmosphere for decades to centuries, and how the “biological carbon pump” helps move organic carbon into the deep ocean.The episode also explores the remarkable engineering effort required to deploy and maintain deep-water moorings in harsh Southern Ocean conditions, and what more than two decades of observations are revealing about ocean acidification, natural variability, and the challenge of detecting long-term human impacts in deep ocean ecosystems.Further reading:IMOS Southern Ocean Time SeriesVoyage information and photo galleryAustralian Antarctic Program PartnershipUnderwater observatory keeps pulse of the Southern Ocean for nearly 30 yearsFor the latest science news visit https://connectsci.au/news

Host David Boldeman speaks with ConnectSci science journalist Imma Perfetto about new research that has, for the first time, measured the hearing range of humpback whales in the wild.The discussion explores why understanding whale hearing is critical, particularly because whales rely heavily on sound for communication, navigation and finding food in the dark ocean environment. Imma explains that studying Baleen Whale hearing has long been difficult since these massive animals cannot be kept in captivity. This means scientists previously relied on indirect estimates based on anatomy and vocalisation patterns.Discover how researchers overcame this challenge by adapting a behavioural hearing test used for human infants, broadcasting sound signals to migrating humpback whales off the Queensland coast and observing changes in their behaviour.For the latest research and discoveries visit https://connectsci.au/news

David Boldeman is joined by science journalist Ellen Phiddian to explore a deceptively simple question: how do scientists actually know the oceans are warming?The conversation unpacks the global network of measurements that allow researchers to track heat across the world’s oceans, from early ship-based observations to modern satellite systems and autonomous Argo floats that dive thousands of metres beneath the surface.Along the way, the episode explains why ocean heat content is one of the most important indicators of climate change, how scientists distinguish long-term warming from natural variability, and why the oceans absorb the vast majority of the excess heat in the Earth’s climate system.It is a story about evidence, measurement and the remarkable ability of modern science to take the temperature of a changing planet.For the latest research and discoveries visit https://connectsci.au/news

Four and a half thousand years ago, people were already navigating the dangerous waters of the High Arctic. In this episode of the ConnectSci Podcast Ultramarine series, David Boldeman speaks with journalist Evrim Yazgin about new research showing how ancient Arctic communities crossed open ocean, thrived in extreme environments, and even helped shape the ecosystems around them.For the latest science news visit connectsci.au/news

We travel nearly ten kilometres beneath the surface of our own planet to explore one of the most extraordinary discoveries in modern science.For decades, the search for extraterrestrial life has focused on distant planets and far-off stars. But some of the most compelling clues may be hiding in the deepest trenches of Earth’s oceans. In total darkness, under crushing pressure and without any sunlight, scientists have discovered thriving ecosystems powered not by light, but by chemistry.Host David Boldeman and ConnectSci journalist Evrim Yazgin unpack how these deep-sea organisms survive using chemosynthesis, breaking down chemicals like hydrogen instead of relying on photosynthesis.READ MORE: https://connectsci.au/news/news-parent/6784/Clues-to-extraterrestrial-life-found-in-deep-sea

Mosquitoes are usually framed as pests and disease carriers. But what if they are simply one of the most successful species at adapting to the environments we have built?In this episode Ultramarine, David Boldeman is joined by medical entomologist Dr Véronique Paris to explore the hidden water systems inside our cities and how they shape mosquito life.Véronique is a Research Fellow in Medical Entomology and Vector Population Control, at the University of Melbourne: https://www.instagram.com/mozzienique/This podcast is brought to you by ConnectSci, the home of fact-based content you can trust. For the latest science news and discoveries visit https://connectsci.au/news

Ocean currents are the hidden systems that regulate Earth’s climate, moving heat and energy around the planet. But as the ocean warms, those currents are beginning to shift, with major consequences for Australia.In this episode of the Ultramarine, science journalist Ellen Phiddian explains how ocean currents work, how scientists track their movement, and why predicting their future is so complex. The conversation explores changes already being observed, from the Antarctic Circumpolar Current to the East Australian Current pushing further south along Australia’s east coast.Together, the episode unpacks what scientists know, what remains uncertain, and why Australia, as an island continent surrounded by multiple ocean systems, is particularly exposed to changes in ocean circulation. Understanding how the ocean moves, it turns out, is essential to understanding Australia’s climate future.More information:Earth Nullschool: An interactive global map that shows ocean currents, winds, and temperatures moving around the planet in near real time. A great way to visualise systems like the East Australian Current.Integrated Marine Observing System (IMOS): Australia’s national network of ocean sensors, moorings, and observing platforms used to track ocean currents, temperature, and conditions around the coastline.For the latest science news and discoveries visit https://connectsci.au/news

David Boldeman is joined by science journalist Ellen Phiddian to explore the strange and often misunderstood physics of tides. The conversation unpacks why most coastlines experience two tides a day, why tidal behaviour varies so dramatically around the world, and what tide charts are actually measuring. Along the way, they examine spring and king tides, the influence of geography and ocean shape, and how tidal forces affect not just the oceans, but the Earth and Moon over deep time including the possibility that tides played a role in the origins of life.For the latest science news and discoveries visit https://connectsci.au/news