Welcome to the 'plastisphere': the synthetic ecosystem evolving at sea

[1] Plastic bottles dominate waste in the ocean, with an estimated 1m of them reaching the sea every minute. The biggest culprit is polyethylene terephthalate (Pet) bottles.

[2] Last month, a study found two bacteria capable of breaking down Pet - or, as the headlines put it, "eating plastic". Known as Thioclava sp. BHET1 and Bacillus sp. BHET2, the bacteria were isolated in a laboratory - but they were discovered in the ocean.

[3] The bacteria are the latest example of new organisms that appear to be growing in a unique environment: the vast amounts of plastic at sea.

[4] Like the atmosphere, magnetosphere and hydrosphere, the plastisphere is a region. But it is also an ecosystem, like the Siberian steppe or coral reefs - a plasticised marine environment. The best-known concentration of seaborne plastic waste is the Great Pacific garbage patch, a sort of plastic soup spread over an area roughly twice the size of France, but plastic is everywhere.

[5] First described in a 2013 study to reter to a collective of plastic-colonising organisms, including bacteria and fungi, the term has since expanded. It now loosely encompasses larger organisms, from crabs to jellyfish, which float across oceans on marine plastics. The term was coined by Linda Amaral-Zettler, a marine microbiologist at the Royal Netherlands lnstitute for Sea Research.

[6] Although the term may be recent, the phenomenon is not. "The plastisphere has been around for as long as plastic has existed," Amaral-Zettler says.

[7] What is new is our understanding of just how complex an ecosystem the world of plastic can be. ln the plastisphere there are organisms that photosynthesise; there are predators and prey; symbionts and parasites, allowing for "a full range of interactions possible, as in other ecosystems", says Amaral-Zettler.

[8] Another unique feature of the plastisphere is that humans invented it. Every other ecosystem has evolved over millions of years. The meaning of that is not yet clear. Wright believes "it's more an issue of scale" because unlike most naturally occurring materiais, plastic is highly durable and persistent, allowing the growth and spread of attached organisms over a massive area.

[9] There are also concerns about plastic-colonising organisms that can travel around the world. Amaral-Zettler's 2013 study discovered Vibrio, a type of bacteria known to contain several species of pathogens, including some associated with gastroenteritis.

[10] For the scientists, the plastisphere's presence is a less obvious concern than its potential health dangers. Most plastic ends up in landfill, but nearly a third of it ends up in the sea. The majority sinks, but a lot does not, becoming a home for all sorts of microbes that might not otherwise have a home.

[11] "At the moment that's still very much an aclive area of research," Wright says. There are two main fields of investigation: potential pathogens in the plastisphere, and the potential for some microbes to biodegrade hydrocarbons, such as the plastic-eaters identified last month.

[12] Those are not unique to the ocean. ln 2016, scientists in Japan discovered ldeonella sakaiensis, a species of bacteria at a rubbish tip that had evolved an enzyme that enabled it to eat plastic.

[13] But another study in the sarne year found that, compared with bacteria in the surrounding waters, those in the plastisphere possessed an enriched collection of genes, suggesting that they had adapted for a "surface-attached lifestyle".

[14] Could the plastisphere evolve in such a way that bacteria would essentially eat it, or at least help us identify ways to break down our plastic waste? "l'd definitely agree that [microbes on] plastics are going to be the key place to look in the fight against plastic," says Wright.

(Adapted from: https://www.theguardian.com)

Welcome to the 'plastisphere': the synthetic ecosystem evolving at sea

[1] Plastic bottles dominate waste in the ocean, with an estimated 1m of them reaching the sea every minute. The biggest culprit is polyethylene terephthalate (Pet) bottles.

[2] Last month, a study found two bacteria capable of breaking down Pet - or, as the headlines put it, "eating plastic". Known as Thioclava sp. BHET1 and Bacillus sp. BHET2, the bacteria were isolated in a laboratory - but they were discovered in the ocean.

[3] The bacteria are the latest example of new organisms that appear to be growing in a unique environment: the vast amounts of plastic at sea.

[4] Like the atmosphere, magnetosphere and hydrosphere, the plastisphere is a region. But it is also an ecosystem, like the Siberian steppe or coral reefs - a plasticised marine environment. The best-known concentration of seaborne plastic waste is the Great Pacific garbage patch, a sort of plastic soup spread over an area roughly twice the size of France, but plastic is everywhere.

[5] First described in a 2013 study to reter to a collective of plastic-colonising organisms, including bacteria and fungi, the term has since expanded. It now loosely encompasses larger organisms, from crabs to jellyfish, which float across oceans on marine plastics. The term was coined by Linda Amaral-Zettler, a marine microbiologist at the Royal Netherlands lnstitute for Sea Research.

[6] Although the term may be recent, the phenomenon is not. "The plastisphere has been around for as long as plastic has existed," Amaral-Zettler says.

[7] What is new is our understanding of just how complex an ecosystem the world of plastic can be. ln the plastisphere there are organisms that photosynthesise; there are predators and prey; symbionts and parasites, allowing for "a full range of interactions possible, as in other ecosystems", says Amaral-Zettler.

[8] Another unique feature of the plastisphere is that humans invented it. Every other ecosystem has evolved over millions of years. The meaning of that is not yet clear. Wright believes "it's more an issue of scale" because unlike most naturally occurring materiais, plastic is highly durable and persistent, allowing the growth and spread of attached organisms over a massive area.

[9] There are also concerns about plastic-colonising organisms that can travel around the world. Amaral-Zettler's 2013 study discovered Vibrio, a type of bacteria known to contain several species of pathogens, including some associated with gastroenteritis.

[10] For the scientists, the plastisphere's presence is a less obvious concern than its potential health dangers. Most plastic ends up in landfill, but nearly a third of it ends up in the sea. The majority sinks, but a lot does not, becoming a home for all sorts of microbes that might not otherwise have a home.

[11] "At the moment that's still very much an aclive area of research," Wright says. There are two main fields of investigation: potential pathogens in the plastisphere, and the potential for some microbes to biodegrade hydrocarbons, such as the plastic-eaters identified last month.

[12] Those are not unique to the ocean. ln 2016, scientists in Japan discovered ldeonella sakaiensis, a species of bacteria at a rubbish tip that had evolved an enzyme that enabled it to eat plastic.

[13] But another study in the sarne year found that, compared with bacteria in the surrounding waters, those in the plastisphere possessed an enriched collection of genes, suggesting that they had adapted for a "surface-attached lifestyle".

[14] Could the plastisphere evolve in such a way that bacteria would essentially eat it, or at least help us identify ways to break down our plastic waste? "l'd definitely agree that [microbes on] plastics are going to be the key place to look in the fight against plastic," says Wright.

(Adapted from: https://www.theguardian.com)

Robo-penguin: how artificial birds are relaying the secrets of ocean currents

[1] lf it looks like a penguin and swims like a penguin - but it's actually a robot - then it must be the latest advance in marine sensory equipment.

[2] The Quadroin is an autonomous underwater vehicle (AUV): a 3D-printed self-propelled machine designed to mimic a penguin in order to measure the properties of oceanic eddies.

[3] It was developed by Burkard Baschek while head of Germany's lnstitute of Coastal Ocean Dynamics ai the Helmholtz Centre Hereon after he watched more than $20,000 of his equipment sink to the bottom of the Pacific Ocean.

[4] Eddies are small ocean currents that other research methods have struggled to capture. They influence all lhe animais and plants in the seas as well as the Earth's climate, driving roughly 50% of all phytoplankton production. The base of the marine food chain, phytoplankton and other marine plants such as kelp and algal plankton also produce up to 70% of atmospheric oxygen.

[5] Despite their significance, eddies are poorly understood within the scientific community because they are small; some are just 10 metres across, and they have an average lifespan of 12 hours, posing a huge challenge for ocean observations. Few detailed measurements even exist.

[6] Baschek first developed a device with about 20 sensors attached to a rope, to be towed behind a ship to measure key oceanographic variables in lhe eddies - such as temperature, salinity, pressure, chlorophyll and oxygen. But the rope would catch on rocks, fishing nets or containers - sending all the data to the seabed.

[7] "The only way to avoid such underwater dangers was to develop a device which can do these measurements without being tied to a rope," says Baschek.

[8] The solution carne from Rudolf Bannasch and his team at the Berlin-based company EvoLogics, which specialises in bionics based on natural evolution. Bannasch knew exactly what Baschek needed: a penguin.

[9] "Penguins provide a shape with optimal aerodynamic characteristics," says Bannasch. His studies in wireless underwater navigation and communication systems suggest that penguins are 20% to 30% more aerodynamic than anything designed in a laboratory, ideal for lhe high-speed measurements Baschek sought.

[10] ln April, lhe first Quadroin prototype - the name derives from "quadro", after the four propellers that move the AUV, and "penguin" - had its maiden voyage in a lake near Berlin. lt has a maximum speed of eight knots (9.2 mph) and uses the sarne sensors that used to be towed on a rope. The Quadroin, however, can float freely through the water, avoiding obstructions, to depths of 150 metres.

[11] One element in the study of eddies that has worried scientists is that they need to be measured in multiple locations simultaneously. Bannasch and his colleagues are working to create two more artificial penguins that would swim in unison and communicate with each other.

[12] "We developed the first singing underwater modems so that the Quadroins will be able to send and receive chirping signals similar to those of dolphins," says Bannasch.

[13] As for losing them to the bottom of the ocean, the artificial penguins have a final trick that also mimics their real-life counterparts: if the electronics fail and the sensors go dark, they float.

(Adapted from: https://www.theguardian.com)