Toxic bacteria found on small pieces of plastic trash from Singapore beaches

NEO CHAI CHIN Today Online 11 Feb 19;

SINGAPORE — The small pieces of plastic trash on Singapore's shores are a hotbed for bacteria, some of which are toxic to humans, a study has found.

Researchers from the National University of Singapore (NUS) discovered more than 400 types of bacteria on 275 pieces of microplastics collected from the beaches of Changi, Sembawang and Lazarus Island between April and July last year.

The bacteria include those associated with coral bleaching (Photobacterium rosenbergii) and those that cause wound infection (Vibrio) or gastroenteritis in humans (Arcobacter).

WHAT ARE MICROPLASTICS?

Microplastics are pieces of plastic that are smaller than 5mm. While some are manufactured — products such as microbeads found in facial scrubs or cosmetics, resin pellets and synthetic fibres — others are the result of the degradation of larger items such as plastic bags.

The study, conducted by NUS Tropical Marine Science Institute senior research fellow Sandric Leong and PhD student Emily Curren, was the first to examine the bacterial community on microplastics found in tropical coastal regions.

It was published last November in the journal Science of the Total Environment.

Plastic pollution is a growing environmental problem worldwide, with more than 150 million tonnes of plastic in the ocean.

Microplastics take longer to degrade in the sea than on land, due to the lower temperatures and presence of salt.

They can be mistaken for food by marine animals such as mussels and fish, which may end up in the stomachs of humans. Studies have found microplastics in human faeces.

They may also leach toxic substances.

BACTERIA: SOME TOXIC, SOME BENEFICIAL

Of the more than 400 types of bacteria that the researchers had discovered on microplastics here and then identified through DNA sequencing, about a third are considered toxic, while about 40 per cent have useful properties, Ms Curren told reporters on Monday (Feb 11).

The latter are able to degrade marine pollutants such as hydrocarbons, for example.

There is not enough evidence to suggest if the remaining bacteria are toxic or beneficial.

But while the “beneficial” bacteria may help in the mitigation of plastic pollution and toxic pollutants, they may not necessarily be good for humans or marine life, she said.

Meanwhile, the discovery of bacteria associated with coral bleaching could have implications for coral reefs around Singapore, especially those under conservation.

The identification of bacteria toxic to humans may help in measures to prevent the spread of diseases.

The researchers found that the bacteria were able to survive two weeks even in dry and dark conditions.

PLASTICS A GOOD HABITAT — FOR BACTERIA

There may be overlaps in the bacteria found on microplastics and other items found in the sea, such as wood or metal debris, said Ms Curren.

“But mostly plastics are a very good habitat for them… because these plastics have grooves that allow bacteria to attach to and because of the sheer volume of the amount of plastic,” she said.

Styrofoam pieces were the most abundant microplastic the researchers found.

Going forward, Ms Curren hopes to investigate if microplastics aid the introduction of foreign organisms, which can disrupt local ecosystems.

She also wants to determine if microplastics help to transport toxic species that, for instance, can contribute to harmful algal blooms which can cause mass fish deaths.

Toxic bacteria found on microplastics along Singapore's coastline
Channel NewsAsia 11 Feb 19;

SINGAPORE: Toxic bacteria that can cause infections on open wounds have been found on microplastics collected from three coastal areas in Singapore.

The National University of Singapore (NUS) said on Monday (Feb 11) its marine scientists found more than 400 types of bacteria on microplastics collected from Lazarus Island, Sembawang Beach and Changi Beach between April and July last year.

During the six-month study, the scientists used DNA sequencing to examine 275 pieces of microplastics, which are pieces of plastic smaller than 5mm in size.

They found species of marine Vibrio - a major cause of wound infections in humans - as well as species of Arcobacter, which is known to cause gastroenteritis.

The team also found the bacteria Photobacterium ronsebergii, which is associated with coral bleaching and disease. The bacteria can be detrimental for the coral reefs in the southern strait of Singapore, which are under conservation.

On the positive side, the team also found species of bacteria capable of degrading plastic and cleaning up oil spills, providing "nature-friendly alternatives" in dealing with pollution from plastics and other toxic materials.

“As the microplastics we studied were collected from locations easily accessible to the public and in areas widely used for recreation, the identification of potentially pathogenic bacteria would be important in preventing the spread of diseases,” said Ms Emily Curren, a PhD student at the Tropical Marine Science Institute (TMSI) and the Department of Biological Sciences at the NUS Faculty of Science.

There are currently more than 150 million tonnes of plastics in the ocean, said NUS. Microplastics, in particular, are often mistaken as food by marine organisms, such as shrimps, mussels and fish.

"This could lead to the accumulation and subsequent transfer of marine pathogens in the food chain," said Dr Sandric Leong, research lead and Senior Research Fellow at TMSI.

"Hence, understanding the distribution of microplastics and identifying the organisms attached to them are crucial steps in managing the plastic pollution on a national and global scale,” Dr Leong added.

Source: CNA/jt(aj)


Toxic bacteria found on microplastics around Singapore's coastline
Cheryl Teh Straits Times 11 Feb 19;

SINGAPORE - Toxic bacteria capable of causing coral bleaching and wound infections in humans have been found on microplastics picked up from the Republic's coastline between April and July 2018.

Marine scientists at the National University of Singapore (NUS) found more than 400 different types of bacteria on 275 pieces of microplastics collected from three beaches - Lazarus Island, Sembawang Beach and Changi Beach.

The plastic items were smaller than 5mm each.

Using DNA sequencing, the scientists found the bacteria Photobacterium rosenbergii, often associated with coral bleaching and disease.

The research team also found species of marine Vibrio - known to be a major cause of wound infections in humans - and species of Arcobacter, a bacteria known to cause gastroenteritis.

The team consists of Dr Sandric Leong, research lead and Senior Research Fellow at the NUS Tropical Marine Science Institute, and Ms Emily Curren, a PhD student at the Institute and the Department of Biological Sciences at the NUS Faculty of Science.

"As the microplastics we studied were collected from locations easily accessible to the public and in areas widely used for recreation, the identification of potentially pathogenic bacteria is important in preventing the spread of diseases," said Ms Curren.

She added that the microplastics originated from disposable forks, spoons and straws, which can take hundreds of years to biodegrade.

These bits and pieces of plastic become "vehicles" for the toxic bacteria to thrive.

When swallowed by fish, the researchers say these harmful bacteria could find their way up the food chain - to humans.

Dr Leong said: "Microplastics form a large population of plastic pollution in marine environments.

"Marine organisms may consume bits of microplastics unintentionally and this could lead to the accumulation and subsequent transfer of marine pathogens in the food chain."

"Understanding the distribution of microplastics and identifying the organisms attached to them are crucial steps in managing plastic pollution on a national and global scale," Dr Leong added.