How marine organisms degrade plastic bags 

How marine organisms degrade plastic bags 

Context: They add to spread of microplastics

A single plastic grocery bag could be shredded by marine organisms into over one million microscopic fragments, a study has found

Amphipod: Orchestiagammarellus

Marine scientists at the University of Plymouth examined the rate at which bags were broken down by the amphipod Orchestiagammarellus, which inhabits coastal areas in northern and western Europe

Main aim

Their main aim was to discover whether different types of plastic and the presence of a biofilm — a layer of organic material which accumulates over time — altered the rate at which such organisms broke down plastic debris

Four times as quickly

Through monitoring in the laboratory and on the shoreline, researchers demonstrated the bags were torn and stretched by Orchestiagammarellus, with microplastics subsequently being found in and around their faecal matter

Presence of biofilm enhanced the shredding

The type of plastic — conventional, degradable and biodegradable — had no effect on the rate of ingestion, however the presence of a biofilm meant the shredding took place around four times as quickly.