Microbes Colonize Plastic Ocean Waste; Cholera Could Use It As Raft And Sail Over To The U.S.
By Rebekah Marcarelli | Jun 27, 2013 04:17 PM EDT
Scientists have found a diverse colony of microbes living on bits of plastic waste in the ocean, dubbed the "plastisphere."
The colonies of bacteria that exist on tiny pieces of plastic are barely the size of a pin. The team of scientists hope to use the plastisphere to unlock the true extent of human consumption on the oceans, according to a Woods Hole Oceanographic Institution press release.
"We're not just interested in who's there. We're interested in their function, how they're functioning in this ecosystem, how they're altering this ecosystem, and what's the ultimate fate of these particles in the ocean," said Linda Amaral-Zettler from the Marine Biological Laboratory (MBL) who worked on the study. "Are they sinking to the bottom of the ocean? Are they being ingested? If they're being ingested, what impact does that have?"
The team used scanning electron microscopy and gene sequencing techniques to identify around 1,000 types of bacteria living in the plastisphere community. The team believes there are even more microbial members of the colony that have yet to be discovered.
The species already discovered include: "plants, algae, and bacteria that manufacture their own food (autotrophs), animals and bacteria that feed on them (heterotrophs), predators that feed on these, and other organisms that establish synergistic relationships (symbionts)."
"The organisms inhabiting the plastisphere were different from those in surrounding seawater, indicating that plastic debris acts as artificial 'microbial reefs," said Tracy Mincer from Woods Hole Oceanographic Institution. "They supply a place that selects for and supports distinct microbes to settle and succeed."
Scientists found evidence suggesting the microbes actually take part in the degradation of the plastic. There were microscopic cracks and craters in the surfaces, which were most likely caused by the bacteria.
"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," said Erik Zettler from the Sea Education Association (SEA). "Now we have to figure out what they are by [genetically] sequencing them and hopefully getting them into culture so we can do experiments."
The microbes could be less friendly than they sound, the plastic acts as a raft which could transport the bacteria to other places. One plastic sample contained bacteria which causes cholera and gastrointestinal maladies.