Macquarie University researchers discovered that just one kind of bacteria in the ocean that help people breathe oxygen is prone to plastic pollution. This kind of bacteria produces ten percent of the oxygen that help people breathe. Results of this study is published in Communications Biology.

"We found that exposure to chemicals leaching from plastic pollution interfered with the growth, photosynthesis and oxygen production of Prochlorococcus, the ocean's most abundant photosynthetic bacteria," says lead author and Macquarie University researcher Dr. Sasha Tetu.

"Now we'd like to explore if plastic pollution is having the same impact on these microbes in the ocean."

It is estimated that more than US13 billion damage to the economy to marine ecosystems annually is caused by plastic pollution. There will be a pressing problem with the prediction that marine plastic pollution will have a greater number than fish by 2050.

"This pollution can leach a variety of chemical additives into marine environments, but unlike the threats posed by animals ingesting or getting entangled in plastic debris the threat these leachates pose to marine life has received relatively little attention," says Dr Lisa Moore, a co-author on the paper.

The researchers were the first to conduct a study on determining the effects of these chemicals in the ocean's photosynthetic marine bacteria.

The green bacteria Prochlorococcus was the subject of the investigation. They contribute largely when it comes to the production of carbohydrate and oxygen in the oxygen through photosynthesis.

"These tiny microorganisms are critical to the marine food web, contribute to carbon cycling and are thought to be responsible for up to 10 percent of the total global oxygen production," says Lisa, explaining the fundamental importance of these microbes to ocean health.

"So one in every ten 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."

"In the lab, the team exposed two strains of Prochlorococcus found at different depths in the ocean to chemicals leached from two common plastic products--grey plastic grocery bags (made from high-density polyethylene) and PVC matting. They found that exposure to these chemicals impaired the growth and function of these microbes--including the amount of oxygen they produce--as well as altering the expression of a large number of their genes," according to Eureka Alert. 

"Our data shows that plastic pollution may have widespread ecosystem impacts beyond the known effects on micro-organisms, such as seabirds and turtles," says Sasha.

"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."