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.

 
 
 
 

How can cities become more bike friendly? The Netherlands offers useful lessons

(Aurore Belot/AFP via Getty Images)

It might seem like cycling is in the DNA of the Netherlands, a country where even the prime minister takes his bicycle to work. But the Dutch haven’t always lived as one with their bikes. In the Amsterdam of the early 1970s, cars were considered the wave of the future. They can be seen filling up squares and streets in historical photographs, and killed an average of over two Amsterdammers per week, including many children.

It is nothing more than an “accident of history” that the Netherlands embraced cycling, says Marco te Brömmelstoet, the director of the Urban Cycling Institute in Amsterdam and a man better known as the city’s cycling professor. Today’s bike rider’s paradise was created after parents and activists took to the streets to protest “child murder” by car. A Saudi oil embargo, rising gas prices, concerns about pollution and anger about the destruction of entire neighbourhoods to build motorways did the rest. 


Amsterdam, 1958. Not a cyclist's paradise. (Keystone/Getty Images)

What’s important about this history is that it can be replicated in other cities, too. Of course, the Netherlands has certain advantages – it’s flat as a pancake, for example. But in the eyes of traffic reformers, the rise of e-bikes (and even cargo bikes) means there’s no excuse for prioritising cars everywhere. 

So how can cities, flat or not, follow Amsterdam’s path to creating places where cycling is a pleasant, safe and common way to get around? The Dutch have some tips. 

Separate bikes from car traffic

Any city could start painting dedicated bike lanes on the streets. But in the Netherlands, those white marks indicating space for cyclists are considered just a minor first step. 

“A line on the road is not enough. Motorists will ignore it,” says Frans Jan van Rossem, a civil servant specialising in cycling policy in Utrecht. If other cities want their residents to choose bikes instead of cars when dodging pandemic-era public transport, protecting them from fast-moving car traffic must be the priority, Van Rossem says. 

The Dutch research institute CROW developed a widely praised design manual for bicycle infrastructure, full of tips for creating these protected lanes: A row of vertical white posts or a curb can serve as a physical separator, for example. Still, cyclists tend to feel safest in a "solitary" path, separated from the road by grass, trees, or an elevated concrete island. 

“The main bottleneck, the main reason why people don’t cycle, is that they don’t feel safe,” Van Rossem notes. “To start, construct separate paths.”

Turn those bike paths into a network

Many cities may have some bike lanes on some streets, but leave cyclists to roll the dice everywhere else. Will conditions still be safe when they turn left or right? Often they have to continue their way without any protected facilities for cyclists. 

“In many cases, cities take fast action, without thinking it through very well,” says Lucas Harms. He leads the Dutch Cycling Embassy, a partnership between the Dutch government and several companies, which promotes Dutch bike knowhow globally. “Don’t build small pieces of bike lane from nothing to nowhere. Think about a network of cycling infrastructure.” 

Utrecht aims to have cyclists within 200 to 300 metres of a connected path anywhere in the city, Van Rossem says. Avoid constructing those paths in sketchy industrial areas, he warns. “A connection through an unattractive area may be fast, but won’t be used a lot.”

Embrace the ‘fietsstraat’, a street where bikes come first


On some streets, drivers have to give up their privileges. (Rick Nederstigt/AFP via Getty Images)

A peculiar Dutch invention called "fietsstraat" (cycling street) holds strong potential for the rest of the world, Kevin Krizek says. He’s a transportation professor from Colorado who spent three years at Radboud University in Nijmegen. 

On cycling streets, cars are “guests”, restricted by a speed limit of 30 kilometres per hour. Drivers are not allowed to pass, so cyclists comfortably dominate the road. In the Netherlands the fietsstraat is usually paved with red asphalt, to resemble a bike path and notify drivers of their secondary status. But creating a cycling street can be easy. “All you need to do is put signs at intersections,” Krizek says. The effect is revolutionary in his view. Drivers have to give up their privileges, and cyclists can take the lead. 

Some Dutch traffic experts worry the cycling street won’t work if a city doesn’t also have a robust cycling culture. In the Netherlands, drivers are aware of the perils of urban cycling because they too use bicycles. Moreover, Dutch cities use sophisticated “circulation plans” to direct cars away from city centres and residential areas, onto a few main routes. 

Without “calming” traffic this way, the cycling street could be a step too far, Harms says. “In a city like New York, where all roads are equally accessible and full, it’s better to separate bicycles and cars,” he says.

Redesign intersections for cyclists' safety

If cyclists have to cross intersections “at the mercy of the Gods”, you’re not there yet, says Harms. When he travels abroad, he often finds clumsily designed crossings. As soon as cars turn, cyclists may fear for their lives. 

Harms recommends placing physical barriers between cars and bikes in places where they must cross. The Dutch build elevated islands to direct traffic into separate sections. The golden rule: cars wait behind bicycles. That way, drivers can see cyclists clearly at all times. Barriers also force Dutch cyclists to turn left in the safest way possible. They cross the street first and wait for their turn again before making their way left.

“You can create that with simple temporary measures,” Harms says. Planters work fine, for example. “They must be forgiving, though. When someone makes a mistake, you don’t want them to get seriously injured by a flower box’s sharp edge.”

Professor Krizek points out how the Dutch integrated cycling routes into roundabouts. Some are small; some are big and glorious, like the Hovenring between Eindhoven and Veldhoven, where cyclists take a futuristic-looking roundabout lifted above the highway. Most of those traffic circles move high volumes of cars and cyclists through intersections efficiently and safely. For a simpler solution, the Dutch manual suggests guiding cyclists to quieter streets – crossing a block up or down may be safer. “Nobody knows how to do intersections better than the Dutch,” says Krizek. 

Ban cars, or at least discourage them


A man rides down from a three-level bicycle parking garage near Amsterdam's main train station. (Timothy Clary/AFP via Getty Images)

The quickest, most affordable way to make a city more bikeable is to ban cars, says Ria Hilhorst, cycling policy advisor for the City of Amsterdam. It will make streets remarkably safe – and will most likely enrage a significant amount of people. 

Amsterdam doesn’t outlaw cars, but it does deliberately make their owners feel unwelcome in the historic city’s cramped streets. Paid parking is hugely effective, for example. Many car owners decide to avoid paying and use bicycles or public transportation for trips into the city. Utrecht, meanwhile, boasts the world’s largest bicycle parking garage, which provides a dizzying 12,500 parking spots.

To further discourage drivers from entering the city’s heart, Amsterdam will soon remove more than 10,000 car-parking spaces. Strategically placed barriers already make it impossible to cross Amsterdam efficiently by car. “In Amsterdam, it is faster to cross the city on a bike than by car,” Harms says. “That is the result of very conscious policy decisions.”

Communicate the benefits clearly

Shopkeepers always fear they will lose clients when their businesses won’t be directly accessible by car, but that’s a myth, says Harms. “A lot of research concludes that better access for pedestrians and cyclists, making a street more attractive, is an economic boost.”

Try replacing one parking space with a small park, he recommends, and residents will see how it improves their community. Home values will eventually rise in calmer, bike-friendlier neighbourhoods without through traffic, Van Rossem says. Fewer cars mean more room for green spaces, for example.

“I often miss the notion that cycling and walking can contribute a lot to the city. One of the greatest threats to public health is lack of exercise. A more walkable and bikeable city can be part of the solution,” says Ria Hilhorst. “But in many countries, cycling is seen as something for losers. I made it, so I have a car and I’m going to use it, is the idea. 

“Changing this requires political courage. Keep your back straight, and present a vision. What do you gain? Tranquility, fewer emissions, health benefits, traffic safety, less space occupied by vehicles.” 

Again, she points to Amsterdam’s history. “It is possible; we were a car city too.”

Karlijn van Houwelingen is a journalist based in New York City.