Science Illustrated

4 WAYS TO SAVE THE OCEAN

Intelligen­t robots identify hot spots for waste, then vacuum-clean the ocean floor

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Scientists are seeking greener ways to restore health and life to our great blue oceans. And the best news is that it’s not yet too late.

More than 90% of plastic waste in the oceans accumulate­s on the ocean floor. A system of artificial­ly intelligen­t robots are set to clean up our mess.

A group of scientists from technical research institutio­ns across Europe have joined forces in the SeaClear project, which has the aim of removing plastic waste from the ocean floor in a new and efficient way. Cleaning up the ocean floor is normally a manual process for human beings, but SeaClear is working on a system by which we can task autonomous robots with the hard work.

The system consists of a mothership that floats on the surface acting as a small command centre, generating electricit­y and providing computer power for the other robots. It also hosts a drone which can fly in the sky above the mothership, equipped with cameras to analyse the ocean surface, mapping out heavy concentrat­ions of plastic waste. Under the ocean surface, two underwater vehicles are operating. The first is equipped with multispect­ral cameras, allowing it to film through even water with poor visibility, and also acoustic sensors that enable the robot to identify plastic waste in the water column. The second robot is a clean-up vessel that removes the waste. Data from the subs is sent to the mothership, where it is combined with data from the drone. The idea is that if there are high levels of plastic in a particular area of the surface and the water column, then there is probably just as much on the ocean floor.

Once the waste has been identified, the clean-up sub sets to work. It is equipped with suction discs and a gripper which it uses to collect plastic and carry it back to the mothership. The mothership is in permanent contact with dry land, so humans can watch progress and give the robots any necessary orders, but the idea is that human interferen­ce won’t often be necessary.

The computer on the mothership uses artificial intelligen­ce to analyse data from the drone and the submarine with the sensors. Scientists are currently teaching the artificial intelligen­ce to identify waste and to differenti­ate between waste, plants and marine animals by showing it pictures from huge online databases. SeaClear will test its system at depths of 20-30 metres in two different environmen­ts where it is imagined that the technology can be used in the future: in the port of Hamburg, where visibility is extremely poor, and in a tourist area near Dubrovnik, Croatia, where visibility is so clear that holiday-makers in the water may constitute a hazard to the system.

Over the next four years, SanClear – supported by the EU – will develop this autonomous plastic vacuum cleaning system. The aim is to deliver a system to locate and collect plastic waste at a success rate of 90%, and with a 70% saving over using human divers.

Hungry nanosponge to save wildlife from oil spills

Scientists have developed a cheap sustainabl­e nanosponge that can suck up 30 times its own weight in oil from the ocean – without endangerin­g wildlife as it does so.

Oil spills are one of the worst disasters that can affect coastal regions. Despite the vast penalties imposed on those responsibl­e, they still take place too often, and the clean-up is expensive, inefficien­t, and harmful to wildlife. A team of scientists headed by the American Northweste­rn University has developed an ‘intelligen­t’ sponge that can suck up 30 times its own weight in oil without absorbing any water. When the sponge has been fully saturated, the oil can be collected without overly damaging the sponge, so that it is subsequent­ly ready for use again.

The core element of this promising invention is a magnetic oil-attracting and water-repellent nanolayer applied to an ordinary sponge. The layer consists of a carbon-based material that includes a high quantity of tiny pores which bind with oil, whereas water passes right through them. Thus the coat makes the sponge effectivel­y able to separate oil from water, with the pores holding on to the oil until the sponge is collected and squeezed to remove it. The process can be repeated 25 times before the sponge’s effectiven­ess declines, making the sponge more reusable than many other clean-up tools.

The nanolayer can be applied to any ordinary sponge; they need only suck up the nanomateri­al and dry before they are ready for use, making the method cheap and easy to scale up. Scientists believe that the method could be adapted so that it could be used not only for oil collection but also to suck up other unwanted particles from water and from air.

Over time, the ‘intelligen­t’ oil sponge could become a sustainabl­e alternativ­e to the familiar clean-up methods that we know today: chemical breakdown, oil burning, skimming the water surface, and removal by means of absorbent materials. All these solutions have drawbacks. Chemical breakdown is harmful for wildlife; burning emits carbon dioxide; skimming doesn’t work in rough seas; and absorbent materials are often expensive and non-reusable. The new sponge, on the other hand, is cheap to make, can be reused many times, and separates oil and water without harming the environmen­t or wildlife.

Smarter fishing could save CO 2

Large fish function naturally as ‘blue carbon’ – carbon dioxide deposits in the ocean. We could save millions of cars’ worth of CO2 if we were to fish in a smarter way, and scientists know how.

Fishing operations emit 25% more CO2 than was previously believed, conclude scientists from the University of California, USA, and Université de Montpellie­r, France, in a new study. This is because the carbon dioxide that the fish emit after being caught should also be included in the calculatio­n.

Until now, the carbon footprint of the fishing industry has primarily focused on the fuel consumptio­n of fishing vessels. But the scientists are pointing to an unrecorded side of fishery pollution – the release of the carbon inside all living creatures. Big fish such as tuna, sharks and swordfish consist of up to 15% carbon. If the fish are removed from the water and broken down over time – when they decay or are eaten – the carbon will eventually combine with oxygen and be emitted to the atmosphere in the form of CO2. When they are not removed from their environmen­t, the fish sink to the bottom when they die, and there the fish – and their carbon – is buried in the sublayers of organic and mineral particles on the ocean floor. The carbon from the dead fish is thereby captured, and prevented from reaching the atmosphere as CO2. Only if the deposits are disturbed will it potentiall­y escape the ocean floor.

So the fish normally function as blue carbon – carbon dioxide deposits in the ocean – and this fresh focus on the blue carbon effect of fish requires a new calculatio­n of the carbon footprint of fisheries. If CO2 emissions from fish are included, ocean fishing has emitted at least 730 million tonnes of carbon dioxide to the atmosphere since 1950. In 2014 alone, ocean fishing emitted the same quantity of CO2 as the annual emissions from 4.5 million cars.

Head researcher Gaël Mariani from Université de Montpellie­r says on the Futurity non-profit site that the new study’s results provide a good reason to support more seasonal and sustainabl­e fishing. Big fish in particular should be better protected, so they can be allowed to die and bury their carbon on the ocean floor. One positive point is that almost half of ocean fishing’s interferen­ce with blue carbon happens in areas where fishing is not financiall­y viable anyway, so that the fishing currently makes sense only when given government subsidies. The scientists hope that unprofitab­le fishing – also some of the most harmful – might not be so difficult to end.

Good news: the oceans could be saved in as little as 30 years

It is not too late to save the oceans. According to research, we could largely restore ocean ecosystems as early as 2050. The challenge is the change required to do so.

One third of ocean fish population­s are overfished, and marine animals’ natural habitats have disappeare­d on a frightenin­g scale. The oceans have become warmer, more acidic, more oxygen-poor, and more polluted. But it is not over yet. A study published in the scientific journal Nature demonstrat­es that the oceans and their wildlife are surprising­ly resilient, and that given a chance to recuperate, they often do. Efforts to preserve them have an genuine effect. The scientists therefore conclude that the oceans could be restored before 2050.

“We have a narrow window in which it is possible to create healthy oceans for our grandchild­ren’s generation, and we have the knowledge and tools to succeed,” says the lead author of the article, Carlos Duarte, Professor of Marine Science. Together with an internatio­nal team of scientists from 10 nations, Duarte has undertaken a meta-study of existing research in the field to deliver an overall picture of the state of our oceans, and they found some encouragin­g evidence. The ocean researcher emphasises that pressure from the commercial fishing industry is declining. The proportion of ‘sustainabl­e’ fishing grew from 60% in 2000 to 68% in 2012. At the same time, the share of endangered marine animals has fallen from 18% in 2000 to 11.4% in 2019. And lastly, half of the oceanic mammal population is growing, including the population of humpback whales that migrate between Antarctica and Australia, which has grown to some 40,000 individual­s from only around 1500 in the 1960s.

In 2000, less than 1% of the oceans were protected – now it is approximat­ely 8%. According to the scientists, it is these efforts that have made the biggest difference. But a return to health for our oceans would require action now to dramatical­ly increase the methods that have been proven to work – regulating fishing, protecting endangered species, limiting ocean pollution, improving the protection of key ocean environmen­ts, and most importantl­y keeping global warming at bay. Such an effort might cost A$15-30bn annually, but the scientists believe the investment would yield a ten-fold return by protecting billions of people who depend on the oceans for their livelihood.

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 ?? SEACLEAR ?? An autonomous clean-up robot grabs plastic with its gripper and carries it to the mothership at the surface.
SEACLEAR An autonomous clean-up robot grabs plastic with its gripper and carries it to the mothership at the surface.
 ??  ?? Oil dissolves the fat layer on bird feathers which normally keep out water and cold.
Oil dissolves the fat layer on bird feathers which normally keep out water and cold.
 ??  ?? Around 100 million sharks are killed annually by the fishing industry, the vast majority for their fins, used in soup popular in Chinese banquets, or as bycatch which is thrown back overboard.
Around 100 million sharks are killed annually by the fishing industry, the vast majority for their fins, used in soup popular in Chinese banquets, or as bycatch which is thrown back overboard.
 ??  ?? All seven species of sea turtles are endangered due to illegal shell and egg trading, fishing and pollution. But that could be reversed, say scientists.
All seven species of sea turtles are endangered due to illegal shell and egg trading, fishing and pollution. But that could be reversed, say scientists.
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