Deep-sea creatures are interconnected across globe via hidden ocean ‘superhighway'
The research, published in the journal Nature, provides a detailed global map of marine creatures closely related to starfish called brittle stars.
Researchers at Australia's Museums Victoria Research Institute assessed how these spiny creatures occupied every ocean, from tropical shallows to icy depths stretching from the equator to the polar regions.
They analysed DNA from nearly 2,700 brittle star specimens taken during hundreds of research expeditions and housed in 48 natural history museums worldwide and found that these creatures had crossed entire oceans over millions of years.
The gradual migration of these deep-sea creatures led to invisible links forming between ecosystems as far apart as Iceland and Tasmania, they found.
Brittle stars have lived for over 480 million years and come to occupy all ocean floors, including at depths of over 3,500 meters.
'You might think of the deep sea as remote and isolated, but for many animals on the seafloor, it is actually a connected superhighway,' Tim O'Hara, lead author of the study, said. 'Over long timescales, deep-sea species have expanded their ranges by thousands of kilometres. This connectivity is a global phenomenon that's gone unnoticed, until now.'
The study also examines the critical role played by these creatures in marine ecosystems across all the oceans. While life forms in shallow waters are restricted by temperature boundaries, the deep-sea environments are more stable, allowing species to disperse over vast distances.
In such environments, brittle stars produce yolk-rich larvae that drift on currents for extended periods, giving them the ability to colonise far-flung regions.
'These animals don't have fins or wings, but they've still managed to span entire oceans. The secret lies in their biology,' according to Dr O'Hara, 'their larvae can survive for a long time in cold water, hitching a ride on slow-moving deep-sea currents.'
Deep-sea ecosystems are more closely related across regions than their shallow-water counterparts. Marine animals off southern Australia, for instance, share close evolutionary links with species in the North Atlantic, on the other side of the planet.
'A close relationship exists between deep-sea faunas of the northern Atlantic and, on the opposite side of the globe, southern Australia,' researchers said.
But extinction events, environmental change and geography have over the millennia created a patchwork of biodiversity across the seafloor.
'It's a paradox,' Dr O'Hara explained. 'The deep sea is highly connected, but also incredibly fragile. Understanding how life is distributed and moves through this vast environment is essential if we want to protect it, especially as threats from deep-sea mining and climate change increase.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Guardian
9 hours ago
- The Guardian
‘A bellwether of change': speed of glacier shrinking on remote Heard Island sounds alarm
Glaciers on a remote Australian sub-Antarctic island are shrinking rapidly, losing almost a quarter of their size in just 70 years, with researchers fearing glaciers on a neighbouring peninsula may have already disappeared. Analysis of aerial photographs and maps going back to 1947 were combined with satellite data to track melting on 29 glaciers on the uninhabited wilderness of Heard Island, 4,100km south-west of Perth and 1,500km north of Antarctica. Scientists said global heating was the most likely cause of the dramatic ice losses. Between 1947 and 2019, the island had warmed by 0.7C, while the area covered by glacial ice fell from 289 sq km to 225 sq km. The most dramatic changes were recorded on the island's east, in particular on Stephenson glacier, which has retreated almost 6km since 1947. In the last 20 years, the glacier retreated on average 178 metres a year, the research, published last week in the scientific journal the Cryosphere, found. 'Glaciers are extremely sensitive to small changes in temperature. As the air warms the ice surface gets closer to melting point,' said Prof Andrew Mackintosh, one of the paper's authors and chief investigator at Monash University's Securing Antarctica's Environmental Future (SAEF). 'I've got no doubt the increase in temperature is primarily responsible for driving the glacier retreat. This shows that no place is free from the influence of climate change.' On the neighbouring Laurens peninsula, where there are 11 small glaciers, the losses were even more dramatic. The 10.5 sq km of glacier ice that was there in 1947 was at just 2.2 sq km in 2019, the final year of data for the research. 'One or two of those glaciers may have already disappeared now,' said Dr Levan Tielidze, the paper's lead author and research fellow at SAEF. 'They are small glaciers, but it's a sign of what will happen in the future to the larger glaciers on Heard. These findings are a bellwether of change for our global climate system.' Sign up to get climate and environment editor Adam Morton's Clear Air column as a free newsletter SAEF is now using climate models to understand what could happen to the island's glaciers in the future under different levels of greenhouse gas emissions. Mackintosh said: 'Although this mapping shows stark glacier retreat and further ice loss is unavoidable, whether we retain glaciers or lose most of them entirely is up to humans and the greenhouse gas emission pathway we follow. 'It might also mean the difference between a future where biodiversity is devastated, or one where key parts are secured.' Heard Island made headlines earlier this year when Donald Trump listed it as being subject to a 10% trade tariff, despite nobody actually living there. The pristine world heritage-listed island includes Australia's only active volcano, Big Ben, and is a magnet for seabirds such as penguins, petrels and albatross, as well as elephant seals and unique slow-growing cushion plants. Dr Justine Shaw, an associate professor at SAEF with the Queensland University of Technology, visited the island in 2003. Sign up to Clear Air Australia Adam Morton brings you incisive analysis about the politics and impact of the climate crisis after newsletter promotion 'It is an absolutely mind-blowing place – a glaciated island,' she said. 'You're on a beach surrounded by elephant seals with king penguins all around and then swooping down from the mountain are sooty albatross calling at each other. 'There's this incredible wildlife and you have your feet in black volcanic sand. And it's right at the southern limit of where plants can grow.' The island has only one weed and no other invasive species, she said, which made it a perfect place to study the impact of climate change on the island's biodiversity. Shaw said the glacial retreat could be generating risks for the unique plant life – a combination of cushion plants, a cabbage, and the insects that live on them. More bare ground exposed by the retreating glaciers created a chance invasive plants could take hold, she said. The appearance of a growing lagoon at the bottom of Stephenson glacier could also be destabilising the ground used by birds for nesting. 'The lagoon that's growing there is opened up to the sea. That will cause erosion,' she said. The government's Australian Antarctic Program this week announced two scientific visits to the island later this year – the first expeditions in more than 20 years. Shaw is organising a team of scientists to travel on the expedition to study the island's unique combination of insects and plants that she said existed nowhere else on Earth. While she was not surprised the glaciers were retreating, she added: 'What's amazing is the rate of the melting – it is so rapid.'
The Independent
15 hours ago
- The Independent
DNA breakthrough reveals hidden links between deep-sea creatures
A new study published in Nature suggests that deep-sea creatures are interconnected globally via a hidden 'superhighway'. Researchers analysed DNA from nearly 2,700 brittle star specimens, finding that these creatures have crossed entire oceans over millions of years. This gradual migration has formed invisible links between deep-sea ecosystems as distant as Iceland and Tasmania. Brittle stars achieve this vast dispersal because their yolk-rich larvae can survive for extended periods, drifting on slow-moving deep-sea currents. While highly connected, the deep sea is also incredibly fragile, facing increasing threats from deep-sea mining and climate change.
The Independent
16 hours ago
- The Independent
Deep-sea creatures are interconnected across globe via hidden ocean ‘superhighway'
Marine animals living in the cold, dark depths of the ocean are interconnected across the world by a hidden 'superhighway', a groundbreaking new study suggests. The research, published in the journal Nature, provides a detailed global map of marine creatures closely related to starfish called brittle stars. Researchers at Australia's Museums Victoria Research Institute assessed how these spiny creatures occupied every ocean, from tropical shallows to icy depths stretching from the equator to the polar regions. They analysed DNA from nearly 2,700 brittle star specimens taken during hundreds of research expeditions and housed in 48 natural history museums worldwide and found that these creatures had crossed entire oceans over millions of years. The gradual migration of these deep-sea creatures led to invisible links forming between ecosystems as far apart as Iceland and Tasmania, they found. Brittle stars have lived for over 480 million years and come to occupy all ocean floors, including at depths of over 3,500 meters. 'You might think of the deep sea as remote and isolated, but for many animals on the seafloor, it is actually a connected superhighway,' Tim O'Hara, lead author of the study, said. 'Over long timescales, deep-sea species have expanded their ranges by thousands of kilometres. This connectivity is a global phenomenon that's gone unnoticed, until now.' The study also examines the critical role played by these creatures in marine ecosystems across all the oceans. While life forms in shallow waters are restricted by temperature boundaries, the deep-sea environments are more stable, allowing species to disperse over vast distances. In such environments, brittle stars produce yolk-rich larvae that drift on currents for extended periods, giving them the ability to colonise far-flung regions. 'These animals don't have fins or wings, but they've still managed to span entire oceans. The secret lies in their biology,' according to Dr O'Hara, 'their larvae can survive for a long time in cold water, hitching a ride on slow-moving deep-sea currents.' Deep-sea ecosystems are more closely related across regions than their shallow-water counterparts. Marine animals off southern Australia, for instance, share close evolutionary links with species in the North Atlantic, on the other side of the planet. 'A close relationship exists between deep-sea faunas of the northern Atlantic and, on the opposite side of the globe, southern Australia,' researchers said. But extinction events, environmental change and geography have over the millennia created a patchwork of biodiversity across the seafloor. 'It's a paradox,' Dr O'Hara explained. 'The deep sea is highly connected, but also incredibly fragile. Understanding how life is distributed and moves through this vast environment is essential if we want to protect it, especially as threats from deep-sea mining and climate change increase.'
