Science

Alarming study finds plastic ocean pollution harms bacteria that produce the oxygen we breathe

Chemicals that leach out of plastic rubbish were found to impair the growth of bacteria in the ocean responsible for producing a large volume of the oxygen in our atmosphere
Chemicals that leach out of plastic rubbish were found to impair the growth of bacteria in the ocean responsible for producing a large volume of the oxygen in our atmosphere

An important new study is raising novel concerns over the effects of plastic pollution in our oceans. For the first time researchers investigated how a common ocean bacteria, responsible for producing over 10 percent of oxygen in the atmosphere, is negatively impaired by chemicals that can leach out of plastic products.

Prochlorococcus is a tiny cyanobacterial genus that was only discovered a little over 30 years ago. This remarkable cyanobacterium is not only the smallest photosynthesizing organism on the planet, but also one of the most abundant. Some estimates suggest there are as much as three octillion Prochlorococcus in the ocean, where they not only help keep the waters healthy, but also produce a substantial volume of the oxygen we breathe.

"These tiny microorganisms are critical to the marine food web, contribute to carbon cycling and are thought to be responsible for up to 10 per cent of the total global oxygen production," says Lisa Moore, from Australia's Macquarie University and co-author on the new study. "So one in every 10 breaths of oxygen you breathe in is thanks to these little guys, yet almost nothing is known about how marine bacteria, such as Prochlorococcus respond to human pollutants."

To fill this substantial gap in scientific knowledge, the researchers took two different strains of the cyanobacteria and in laboratory conditions exposed them to chemicals known to leach out of common plastic products. The results were striking with the chemicals impairing the Prochlorococcus' growth, reducing its ability to photosynthesize, and altering the expression of a large number of its genes.

The study obviously has a number of limitations if one is trying to extrapolate these results to the general effect of plastics in the ocean. The researchers do note that their experiments do not equate to specific concentrations of plastics in the ocean, but instead they're designed to try to better understand what the impact of plastic pollution could be on this vitally important population of microorganisms in our marine systems.

"Our data shows that plastic pollution may have widespread ecosystem impacts beyond the known effects on macro-organisms, such as seabirds and turtles," says lead author on the study, Sasha Tetu. "If we truly want to understand the full impact of plastic pollution in the marine environment and find ways to mitigate it, we need to consider its impact on key microbial groups, including photosynthetic microbes."

While a great deal of activity currently circles the problem of plastics, and microplastics, in our ocean ecosystems, very little is known about what actual damage these pollutants are causing. Further study will be necessary to investigate the effects of these plastics on microorganisms in the actual ocean, but the researchers hypothesize this to potentially be a significant global issue.

The new study notes the nearly two trillion plastic pieces that make up the infamous Great Pacific Garbage Patch cross over an area where the Prochlorococcus cyanobacterium is most abundant. Alongside this, a recent study did reveal that floating plastic rubbish can leach chemicals into ambient seawater in volumes high enough to alter the activity of local microbial populations. So, although this new research was completed in laboratory environments in generally hypothetical scenarios, the problem of plastic chemicals leaching into the ocean is one that certainly needs attention.

The new study was published in the journal Communications Biology.

Source: Macquarie University

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9 comments
SimonClarke
Plastic, plastic, plastic. Yes, we know there is a major problem, yes we know it is ultra bad for the environment and for animals but we don't need to be told about it all of the time. Each of us needs to do our bit to minimise the impact but unfortunately this doesn't help get rid of any plastic that is already in our rivers or oceans.
To quote comedian Diane Spencer, Ferret or Box. Problem or solution. Vegware makes an awesome range of compostable plastics, as well as other items including palm plates, that breakdown in as little as six weeks in a compost environment, more articles should be done about what this company, and others like it, are doing.
ChiliDog
I agree. I am tired of hearing about how horrible people are to the environment. People aren't going to suddenly disappear. We are part of the planet too. So, tell me what I can do to help while not having to commit genocide or go back to living like people did in the pre-industrial age. The world population is going to continue to grow, so we need new ways of doing things and less harping on the same thing over and over and over. Give me more articles on cool stuff that I can use that is beneficial to the environment and less on how awful it is to be human.
Buzzclick
I am becoming convinced that most of the plastic in our oceans are coming from less-developed countries that have little facility in their infrastructure to handle waste, particularly plastic. It ends up in the rivers and on to the seas. I have yet to see studies that include ocean currents to find the sources, but I would certainly expect them to exist.
And why hasn't there been a concerted international effort to mitigate this situation of two trillion bits of plastic in the Great Pacific Garbage Patch? Probably because it's not profitable, and it's out-of-sight-out-of-mind. People have to speak up and make a stink till something is done.
notarichman
what i don't like about researches such as these... testing using the chemicals in higher degree than is produced by a factor of 'x' currently in the oceans. i.e. 1 part per thousand versus 1 part per billion? the leached chemicals take how long to start? how many thousands of years for the plastic bottle to disintegrate? i agree that plastic in the oceans is a bad thing, but please keep the research reasonable and the media hype also reasonable.
Infragreen
Huh. So y'all are tired of hearing about how problematic we humans are and just want to bury your heads in the sand. I completely disagree. We need to keep slamming this into everyone face until something is done.
Douglas Bennett Rogers
We used to have reusable glass pop bottles until they were stopped by lawsuits. The same people have pushed us into bottled water. Now they are pushing us into very expensive biodegradable construction.
EZ
I get tired of hearing "I'm at fault" again and again. Isn't it about time we look at the true source of such problems? How about the cold blooded morons that use the stuff to make products we need to use? In other-words--big business.
aksdad
Pssst. Pass this story along to the countries in southeast Asia and Africa that dump plastic in the ocean. The rest of the world banned dumping at sea decades ago.
amazed W1
ChilliDog is right to want more statements about what we can do, but people really might just disappear, when pollution and overconsumption of scarce resources get us all in a pincer movement, which is the reason this research cannot be ignored. It might not happen till our great grandchildren are around, and might be prevented by Mother Natures usual means of controlling excess populations, starvation, disease or wars, but that isn't much more desirable.
Also a comment for EZ, much as I also dislike global big business, in spite of the deadly advertising, they sell only what we buy, so we as individuals must behave responsibly and not buy what we don't need and/or go back to living with much more sustainable "things"..