Abstract
Microplastic particles have been found in all the world’s oceans. Since their surfaces are microbially colonised, research is currently determining whether microbes are able to degrade the synthetic polymers. We show that their contribution to the biodegradation of plastics seems to be extremely limited. Also, it is unlikely that microbes specialise in plastic degradation through evolutionary adaptation. This is not only due to the great diversity and simultaneous very low bioavailability of microplastics in the oceans, but also because it is energetically disadvantageous.