I explored the Antarctic deep seas for Blue Planet II – and it was like going back 350m years

Ooooh. Image: BBC.

“It has always been our ambition to get inside that white space, and now we are there the space can no longer be blank,” wrote the polar explorer Captain Scott, on crossing the 80th parallel of the Antarctic continent for the first time in 1902. Fast-forward more than a century – and the deep ocean floor around Antarctica still offers a “white space”, beyond the reach of scuba divers, only partially mapped in detail by sonar from ships and seldom surveyed by robotic vehicles.

So I jumped at the chance to join a team from the BBC on an expedition to the Antarctic Peninsula for Blue Planet II, to help them as a scientific guide. Thanks to the crew of the research ship Alucia, we dived in minisubmarines to 1km deep in the Antarctic for the first time. And while we didn’t face anything like the physical hardships endured by early polar explorers on land, those dives did give us the opportunity for some unique science.

The deep ocean around Antarctica is a special place for several reasons. Because Antarctica is pushed down by the weight of its ice sheets, the submerged continental shelf around it is deeper than usual, around 500-600m deep at its edge rather than 100-200m deep. It’s also cut by even deeper channels close inshore, some plunging more than 1km, scoured out by larger ice sheets in the past. So although the continent itself is remote, we can reach the deep ocean close inshore here – handy for us diving in minisubmarines, despite the need to dodge icebergs.

Giant sponges found in the deep waters of the Antarctic. Image: BBC NHU.

There’s a gateway to the deep for marine life here too. Some deep-sea animals come into much shallower depths than usual around Antarctica, because the water temperature near the surface is similar to the cold temperatures elsewhere in the deep ocean. And in the past, shallow-living ancestors of some deep-sea animals spread out across the deep oceans from the Antarctic, via this cold gateway between the shallows and the deep.

One of my favourite animals that we saw on dives was the octopus Graneledone antarctica, whose ancestor ventured down from the shallows around 15m years ago, when the water temperature at the surface cooled to the same chilly temperature as the deep. Her descendants then spread out across the abyss like wagon-train pioneers, giving rise to several different species of deep-sea octopus found around the world today. Some stayed behind, however, becoming the species that we saw.

The ocean around Antarctica is also the lungs of the deep. Much of the life-giving oxygen in deep waters across the world begins its journey from the atmosphere here. As seawater freezes around the white continent in winter, it leaves behind very cold and salty water that sinks and flows into the depths of the Atlantic, Indian and Pacific Oceans – even the deepest water in the ocean, at the bottom of the Marianas Trench 14,000km away, came from here. As this deep water flows out from the Antarctic, it carries oxygen, dissolved from the atmosphere at the surface. So the Antarctic is where the world’s deep oceans breathe in – and its waters are among the most oxygen-rich on our planet.

Another of my favourite animals from our dives takes advantage of those oxygen-rich waters: giant sea-spiders, with legspans up to 40cm across. Sea spiders lack a respiratory system, which usually limits their size, but can grow much larger in the oxygen-rich conditions here.


‘Ancient ocean ecosystems’

Diving in the Antarctic is also a journey back in time, to glimpse what ancient ocean ecosystems were once like. Fish dominate as predators in most marine ecosystems today, but few fish species can cope with the -1.5℃ conditions where we were diving. The “ice dragonfish”, Cryodraco antarcticus, is a notable exception, however, and another of my favourite animals – with antifreeze proteins that stop its blood from icing up. Its blood is also clear, without any of the oxygen-carrying haemoglobin that gives ours its red colour – in the cold waters, enough oxygen dissolves directly in the fluid of the fish’s blood to keep it alive.

But there are few fish with remarkable adaptations like the ice dragon, and so invertebrates have diversified to dominate as predators in the deep ocean here, just as they did throughout the oceans more than 350m years ago. A final favourite from our dives epitomises that: the Antarctic sunstar Labidiaster annulatus, which is a relative of the familiar five-armed starfish. Nicknamed “the Death Star” by those inside the subs who watched its behaviour, it has up to 50 arms and grows larger than a dinner plate. It uses those arms like fishing rods, holding them up off the seabed to snag passing krill, thanks to tiny pincers on its skin that snap shut when anything brushes past them. Unlike other starfish, Labidiaster can wave its arms to catch prey here because there are relatively few predatory fish to chew them off.

A feather star dances in the deep waters of the Antarctic Sound. Image: BBC NHU.

The ConversationOverall, seeing the deep Antarctic sea floor close-up from our minisubs should help us to understand how “dropstones” shape the pattern of life here. “Dropstones” are car-sized boulders that fall from passing icebergs – they provide “islands” of rocky habitat for filter-feeding species which otherwise don’t get a look-in on the soft mud of the Antarctic seafloor. But where the dropstones settle depends on the undersea terrain. As we found on our dives, they slide down steeper undersea slopes, actually scraping off marine life. But if you’re at the bottom of a gully, then lots of dropstones end up there, giving a major boost to local biodiversity. That pattern of life is hard to see from samples collected by nets or trawls in the past, so our first minisub dives to 1km deep in the Antarctic should help to make that “white space” no longer such a blank.

Jon Copley is associate professor in ocean exploration & pbblic engagement at theUniversity of Southampton.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

A growing number of voters will never own their own home. Why is the government ignoring them?

A lettings agent window. Image: Getty.

The dream of a property-owning democracy continues to define British housing policy. From Right-to-Buy to Help-to-Buy, policies are framed around the model of the ‘first-time buyer’ and her quest for property acquisition. The goal of Philip Hammond’s upcoming budget – hailed as a major “intervention” in the “broken” housing market – is to ensure that “the next generation will have the same opportunities as their parents to own a home.”

These policies are designed for an alternative reality. Over the last two decades, the dream of the property-owning democracy has come completely undone. While government schemes used to churn out more home owners, today it moves in reverse.

Generation Rent’s new report, “Life in the Rental Sector”, suggests that more Britons are living longer in the private rental sector. We predict the number of ‘silver renters’ – pensioners in the private rental sector – will rise to one million by 2035, a three-fold increase from today.

These renters have drifted way beyond the dream of home ownership: only 11 per cent of renters over 65 expect to own a home. Our survey results show that these renters are twice as likely than renters in their 20s to prefer affordable rental tenure over homeownership.

Lowering stamp duty or providing mortgage relief completely miss the point. These are renters – life-long renters – and they want rental relief: guaranteed tenancies, protection from eviction, rent inflation regulation.

The assumption of a British ‘obsession’ with homeownership – which has informed so much housing policy over the years – stands on flimsy ground. Most of the time, it is based on a single survey question: Would you like to rent a home or own a home? It’s a preposterous question, of course, because, well, who wouldn’t like to own a home at a time when the chief economist of the Bank of England has made the case for homes as a ‘better bet’ for retirement than pensions?


Here we arrive at the real toxicity of the property-owning dream. It promotes a vicious cycle: support for first-time buyers increases demand for home ownership, fresh demand raises house prices, house price inflation turns housing into a profitable investment, and investment incentives stoke preferences for home ownership all over again.

The cycle is now, finally, breaking. Not without pain, Britons are waking up to the madness of a housing policy organised around home ownership. And they are demanding reforms that respect renting as a life-time tenure.

At the 1946 Conservative Party conference, Anthony Eden extolled the virtues of a property-owning democracy as a defence against socialist appeal. “The ownership of property is not a crime or a sin,” he said, “but a reward, a right and responsibility that must be shared as equitable as possible among all our citizens.”

The Tories are now sleeping in the bed they have made. Left out to dry, renters are beginning to turn against the Conservative vision. The election numbers tell the story of this left-ward drift of the rental sector: 29 per cent of private renters voted Labour in 2010, 39 in 2015, and 54 in June.

Philip Hammond’s budget – which, despite its radicalism, continues to ignore the welfare of this rental population – is unlikely to reverse this trend. Generation Rent is no longer simply a class in itself — it is becoming a class for itself, as well.

We appear, then, on the verge of a paradigm shift in housing policy. As the demographics of the housing market change, so must its politics. Wednesday’s budget signals that even the Conservatives – the “party of homeownership” – recognise the need for change. But it only goes halfway.

The gains for any political party willing to truly seize the day – to ditch the property-owning dream once and for all, to champion a property-renting one instead – are there for the taking. 

David Adler is a research association at the campaign group Generation Rent.

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