Scientists Find Microbes Thriving in Ocean Plastisphere
Posted on June 27, 2013
Scientists have discovered microbes colonizing and thriving on flecks of plastic that have polluted the oceans. The scientists are calling the floating plastic communities the plastisphere. They say it represents a novel ecological habitat and raises numerous questions, such as how will it change the overall ocean ecosystem and could pathogens be transported to new locations thanks to the plastiphere?
The study was published here in Environmental Science & Technology. The team of scientists - Erik Zettler from Sea Education Association (SEA), Tracy Mincer from Woods Hole Oceanographic Institution (WHOI), and Linda Amaral-Zettler from the Marine Biological Laboratory (MBL) - analyzed tiny marine plastic debris that was skimmed from the sea surface at several locations in the North Atlantic Ocean.
The scientists found at least 1000 different types of bacterial cells on the plastic samples, including many individual species yet to be identified. The plastic debris represents a new mode of transportation, acting as rafts that can convey harmful microbes, including disease-causing pathogens and harmful algal species. One plastic sample was dominated by members of the genus Vibrio, which includes bacteria that cause cholera and gastrointestinal maladies.
Micner said in a statement, "The organisms inhabiting the plastisphere were different from those in surrounding seawater, indicating that plastic debris acts as artificial microbial reefs. They supply a place that selects for and supports distinct microbes to settle and succeed."
On the plus side, the scientists also found evidence some of the microbes may play a role in degrading plastics. They saw microscopic cracks and pits in the plastic surfaces that may have been created by microbes embedded in them.
Zettler, who added that undergraduate students participating in SEA Semester cruises collected and processed the samples, says, "When we first saw the 'pit formers' we were very excited, especially when they showed up on multiple pieces of plastic of different types of resins. Now we have to figure out what they are by [genetically] sequencing them and hopefully getting them into culture so we can do experiments."