Plastic pollution harms oxygen-producing ocean bacteria

A research team led by ARC Discovery Early Career Researcher Award (DECRA) recipient, Dr Sasha Tetu, and including ARC Australian Laureate Fellow, Professor Ian Paulsen, has shown that a group of ocean bacteria, critical to the world’s oxygen supply, are susceptible to plastic pollution.

Researchers have estimated that plastic pollution causes more than US$13 billion in economic damage to marine ecosystems each year, and the problem is only getting worse. The amount of marine plastic pollution is estimated to be so large, and increasing so much, that it will outweigh the fish in the oceans by 2050.

This pollution poses well-known threats to animals who are injured or killed by ingesting it or by getting entangled in plastic debris. However, plastic can also leach a variety of chemical additives into marine environments, and the threat that these leachates pose to marine life has received comparatively little attention.

The research team performed laboratory experiments to show that these leached chemicals impair the growth and function of a tiny, green bacteria called Prochlorococcus, which is probably the most abundant photosynthetic organism on Earth, responsible for up to ten percent of global oxygen production.

These photosynthetic bacteria are also critical to the marine food web and contribute to carbon cycling. The implication of the discovery is that plastic pollution may have serious widespread ecosystem impacts beyond the already known effects on larger animals.

	TEN PER CENT OF THE OXYGEN WE BREATHE COMES FROM JUST ONE KIND OF BACTERIA IN THE OCEAN.

 

(Below): Dr Sasha Tetu, with PhD student, Ms Indrani Sarker. Flasks show healthy marine bacteria Prochlorococcus (green) and bleached, dead cultures following exposure to plastic leachates.