Sludge, snags, and surreal animals: life aboard a voyage to study the abyss

The famous “faceless fish”, which garnered worldwide headlines when it was collected by the expedition.
Rob Zugaro, Author provided

Tim O’Hara, Museum Victoria

Over the past five weeks I led a “voyage of discovery”. That sounds rather pretentious in the 21st century, but it’s still true. My team, aboard the CSIRO managed research vessel, the Investigator, has mapped and sampled an area of the planet that has never been surveyed before.

The RV Investigator in port.
Jerome Mallefet/FNRS

Bizarrely, our ship was only 100km off Australia’s east coast, in the middle of a busy shipping lane. But our focus was not on the sea surface, or on the migrating whales or skimming albatross. We were surveying The Abyss – the very bottom of the ocean some 4,000m below the waves.

To put that into perspective, the tallest mountain on the Australian mainland is only 2,228m. Scuba divers are lucky to reach depths of 40m, while nuclear submarines dive to about 500m. We were aiming to put our cameras and sleds much, much deeper. Only since 2014, when the RV Investigator was commissioned, has Australia had the capacity to survey the deepest depths.

The months before the trip were frantic, with so much to organise: permits, freight, equipment, flights, medicals, legal agreements, safety procedures, visas, finance approvals, communication ideas, sampling strategies – all the tendrils of modern life (the thought “why am I doing this?” surfaced more than once). But remarkably, on May 15, we had 27 scientists from 14 institutions and seven countries, 11 technical specialists, and 22 crew converging on Launceston, and we were off.

Rough seas

Life at sea takes some adjustment. You work 12-hour shifts every day, from 2 o’clock to 2 o’clock, so it’s like suffering from jetlag. The ship was very stable, but even so the motion causes seasickness for the first few days. You sway down corridors, you have one-handed showers, and you feel as though you will be tipped out of bed. Many people go off coffee. The ship is “dry”, so there’s no well-earned beer at the end of a hard day. You wait days for bad weather to clear and then suddenly you are shovelling tonnes of mud through sieves in the middle of the night as you process samples dredged from the deep.

Shifting through the mud of the abyss on the back deck.
Jerome Mallefet/FNRS

Surveying the abyss turns out to be far from easy. On our very first deployment off the eastern Tasmanian coast, our net was shredded on a rock at 2,500m, the positional beacon was lost, tens of thousands of dollars’ worth of gear gone. It was no one’s fault; the offending rock was too small to pick up on our multibeam sonar. Only day 1 and a new plan was required. Talented people fixed what they could, and we moved on.

I was truly surprised by the ruggedness of the seafloor. From the existing maps, I was expecting a gentle slope and muddy abyssal plain. Instead, our sonar revealed canyons, ridges, cliffs and massive rock slides – amazing, but a bit of a hindrance to my naive sampling plan.

But soon the marine animals began to emerge from our videos and samples, which made it all worthwhile. Life started to buzz on the ship.

Secrets of the deep

Like many people, scientists spend most of their working lives in front of a computer screen. It is really great to get out and actually experience the real thing, to see animals we have only read about in old books. The tripod fish, the faceless fish, the shortarse feeler fish (yes, really), red spiny crabs, worms and sea stars of all shapes and sizes, as well as animals that emit light to ward off predators.

A spiny red lithodid crab.
Rob Zugaro/Museums Victoria

The tripod fish uses its long spines to sit on the seafloor waiting for the next meal.
Rob Zugaro/Museums Victoria

The level of public interest has been phenomenal. You may already have seen some of the coverage, which ranged from the fascinated to the amused – for some reason our discovery of priapulid worms was a big hit on US late-night television. In many ways all the publicity mirrored our first reactions to animals on the ship. “What is this thing?” “How amazing!”

The important scientific insights will come later. It will take a year or so to process all the data and accurately identify the samples. Describing all the new species will take even longer. All of the material has been carefully preserved and will be stored in museums and CSIRO collections around Australia for centuries.

Scientists identifying microscopic animals onboard.
Asher Flatt

On a voyage of discovery, video footage is not sufficient, because we don’t know the animals. The modern biologist uses high-resolution microscopes and DNA evidence to describe the new species and understand their place in the ecosystem, and that requires actual samples.

So why bother studying the deep sea? First, it is important to understand that humanity is already having an impact down there. The oceans are changing. There wasn’t a day at sea when we didn’t bring up some rubbish from the seafloor – cans, bottles, plastic, rope, fishing line. There is also old debris from steamships, such as unburned coal and bits of clinker, which looks like melted rock, formed in the boilers. Elsewhere in the oceans there are plans to mine precious metals from the deep sea.

Rubbish found on the seafloor.
Rob Zugaro/Museums Victoria

Second, Australia is the custodian of a vast amount of abyss. Our marine exclusive economic zone (EEZ) is larger than the Australian landmass. The Commonwealth recently established a network of marine reserves around Australia. Just like National Parks on land, these have been established to protect biodiversity in the long term. Australia’s Marine Biodiversity Hub, which provided funds for this voyage, as been established by the Commonwealth Government to conduct research in the EEZ.

The newly mapped East Gippsland Commonwealth Marine Reserve, showing the rugged end of the Australian continental margin as it dips to the abyssal plain. The scale shows the depth in metres.
Amy Nau/CSIRO

Our voyage mapped some of the marine reserves for the first time. Unlike parks on land, the reserves are not easy to visit. It was our aim to bring the animals of the Australian Abyss into public view.

We discovered that life in the deep sea is diverse and fascinating. Would I do it again? Sure I would. After a beer.

Tim O’Hara, Senior Curator of Marine Invertebrates, Museum Victoria

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

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Logically, how is it possible to use more resources than Earth can replenish?

According to the WWF, we’re living off 1.6 Earths’ worth of resources.
Kevin Gill/Flickr, CC BY-SA

Bonnie McBain, University of Newcastle

Since the 1970s, humans have used more resources than the planet can regenerate. This is known as overshoot. The WWF Living Planet Report has reported overshoot every two years since 2000.

However, this fact can inspire some confusion. How can it logically be possible for us to use more resources than Earth can produce, for decades on end?

There are two basic concepts at work here. One is our ecological footprint, which can be very loosely understood as a way of tallying up the resources we use from nature. The other is the planet’s ability to provide or renew those resources every year: its “biocapacity”.

When our ecological footprint exceeds Earth’s biocapacity, that’s unsustainable resource use. Unsustainable resource use can occur for some time. The environmental thinker Donella Meadows used a bathtub analogy to explain how.

Imagine a bathtub full of water, with the tap running and the plug out at the same time. It is possible for more water to flow out of the bath than into it for some time without the water in the tub running out. This is because the significant store of water in the bath acts like a buffer. The same goes for nature.

Because nature has accumulated resources – for example, in a forest – it’s possible for us to harvest nature at a greater rate than it can replenish itself for a certain amount of time.

But this leads to the question: if humanity’s ecological footprint exceeds Earth’s biocapacity, how long can we keep going without crossing a tipping point? Our recent research investigates this question.

Explaining the feedback system

It’s important to make the point that nature provides us with literally everything we need, through processes known as ecosystem services. Much of this is obvious because we buy and sell it, as food, shelter and clothing.

Other services go largely unnoticed. Forests provide protection from flooding by slowing down surface water runoff, for example, while mangroves absorb carbon dioxide from the air and store it. Until relatively recently, nature has continued to provide, despite our rapidly increasing ecological footprint.

In part this resilience comes from being able to buffer disturbance with the existing store of resources. But there’s an important mechanism that helps natural systems adjust – to a certain extent – to disruption. This is called a feedback mechanism, and if we take the bathtub analogy one step further we can see how it works.

Say we set up our bathtub so that the tap and the plughole communicate with one another. If more water suddenly starts flowing down the plug, then the tap increases the flow of water into the bath to compensate, thus maintaining the water level. This is an example of a “positive” feedback (more water exiting the bath) being moderated by a “negative” feedback (more water entering from the tap), thus maintaining the state of the system (water in the bath).

Let’s pick a real-world example. Clearing trees from a forest might mean that seeds from the soil have the chance to germinate. If they germinate before the landscape gets too degraded, they can potentially balance out the disturbance.

But harvesting forest also exposes the ground, causing soil loss. In turn, vegetation might find it more difficult to regrow – resulting in yet more soil loss, and so on. This is a “positive” feedback – one that reinforces and exacerbates the original problem.

Negative feedbacks can only adapt to a certain level of disruption. Once the disturbance is too large, they break down. Positive feedback loops can then prevail and the ecosystem is likely to cross a tipping point, resulting in permanent, dramatic and sudden transformation.

Crossing planetary boundaries

In our research, my colleagues and I compared future ecological footprints with research about planetary boundaries (points at which the risks to humanity of crossing a tipping point become unacceptably high). We found the discrepancy between the ecological footprint and biocapacity is likely to continue until at least 2050. We also found that our global cropping footprint is likely to exceed the planetary boundary for land clearing between 2025 and 2035.

This occurs in the context of atmospheric carbon dioxide concentrations that have already crossed the planetary boundary of 350 ppm. (As I write, the carbon dioxide concentration is over 400 ppm.)

By itself, both these points are serious enough. More seriously, we have no idea what happens when two planetary boundaries are approached simultaneously, or two tipping points interact.

We face the permanent loss of essential natural processes, putting, for example, our global food security at risk. Our research shows we need to address gradual, cumulative change, as the global resource buffer shrinks and stabilising feedback mechanisms are overwhelmed.

But there’s good news too. Ecological footprints decrease in response to human decisions. Our current trajectory towards tipping points is not fait accompli at all, but can be influenced by the choices we make now.

Bonnie McBain, Tutor in Sustainability Science, University of Newcastle

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