you're reading...


Ocean plastic pollution damages bacteria that help us breathe

Reviewing: Sarker, I., Moore, L. R., Paulsen, I. T., & Tetu, S. G. (2020). Assessing the toxicity of leachates from weathered plastics on photosynthetic marine bacteria Prochlorococcus. Frontiers in Marine Science7, 777. (DOI: https://doi.org/10.3389/fmars.2020.571929)



During a walk along the beach you might see an endless display of plastic bags, bottles, and cutlery. Over 10 million tons of plastic enter the ocean every year, posing serious threats to millions of marine organisms like fish, seabirds, turtles, whales and seals. While it’s easy to see how plastic can suffocate and endanger these large animals, it might be a bit more difficult to visualize how plastic affects ocean microbes.

Plastic waste on the beach (Wikimedia Commons)

A seagull biting a plastic glove (Pixabay)








When plastic enters the ocean, a number of chemicals in plastic will dissolve in seawater just as sugar juice comes out from sugar beets immersed in water. The chemicals dissolved in water are mostly materials added during plastic production, such as polymerization solvents (what cements units of plastic together), plasticizers (which softens plastic to make it more flexible), dyes and flame-retardants (which makes plastic harder to burn). Seawater that contains these toxic materials from plastic are called “leachates”. The leachates are continually produced as plastic floats around in the ocean for hundreds and thousands of years before it degrades, posing a serious harm to microbes in the ocean.


Prochlorococcus are only about a hundredth of the width of a human hair but can produce so much oxygen! (Wikimedia Commons)

Among many billions of microbes in the ocean, phytoplankton are a specific group of microbes that photosynthesize by using energy from sunlight to take up carbon dioxide and produce oxygen, similar to plants on land. However, marine phytoplankton produce as much oxygen as all land plants do: this means that every other breath you take is coming from marine phytoplankton! But a specific type of phytoplankton called Prochlorococcus produces a tenth of the oxygen produced by all marine phytoplankton. Prochlorococcus are one of the smallest phytoplankton that are present almost everywhere in the global ocean.

Because Prochlorococcus have a big impact in the ocean, scientists looked into the effect of degraded plastic leachates on Prochlorococcus growth and photosynthetic activity in a new paper. The research team put pieces of gray plastic grocery bags and black textured plastic mats into the Lane Cove river (an estuary in Sydney) to degrade plastic in seawater for 17- and 112-days. Researchers then brought the pieces back into the laboratory leached the remaining chemicals from plastic, and exposed leachates to Prochlorococcus.


The research team found that plastic that was weathered longer (for 112 days) released less toxic leachates than plastic that was weathered shorter (for 17 days). However, even the less toxic leachates included high amounts of metals like zinc and copper that were suppressing Prochlorococcus growth. Both leachates greatly impaired Prochlorococcus photosystems, which mean that Prochlorococcus are unable to photosynthesize as efficiently as they can under normal conditions. In addition, both leachates strongly damaged Prochlorococcus cell membranes – the outer layer that protects the cell from the outer environment.


The Great Pacific Garbage Patch is a massive island of trash that traveled from land to the middle of the North Pacific Ocean. (Photograph by Ray Boland, NOAA)

While this study directly added degraded plastic leachates to Prochlorococcus, chances are that marine microbes out in the ocean wouldn’t be exposed to plastic leachates in the way they were in the laboratory, because the ocean is naturally a much more complex environment. For instance, while plastic waste is much more common in the coastal ocean, it takes several weeks or months for plastic pieces from the West Coast to travel all the way to the center of the Pacific Ocean, so microbes living out in the open ocean may be exposed to less plastic leachates. But since plastic can remain in the surface ocean for days, months or even years before it completely degrades, plastic waste can put millions of microbes at risk and disturb the whole marine ecosystem. There’s another reason to think before you grab a plastic beverage cup with a plastic lid and straw, or a takeout lunch wrapped in plastic wrap and put in a plastic bag.



One Response to “Ocean plastic pollution damages bacteria that help us breathe”

  1. JIwoon, This is an very important field of study that needs more research dedicated to determining the magnitude of the problem at finding solutions. Best wishes for success. Ray Buckley, UW/SAFS

    Posted by Ray Buckley | September 23, 2020, 1:11 pm

Post a Comment


  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 6 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 9 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 10 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 11 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com