Marine organisms help disintegrate a plastic bag into 1.75 million pieces
A study by UK’s University of Plymouth says that by tearing apart solid plastics, marinelife actually contributes to the spread of microplastics in the environment.
Ingestion and fragmentation of plastic carrier bags by the amphipod Orchestia gammarellus: Effects of plastic type and fouling load
University of Plymouth
According to marine scientists at the University of Plymouth in the UK, marine organisms are able to tear apart a single plastic bag into 1.75 million microscopic pieces.
When introduced to biofilm, the activity was found to have increased fourfold.
The research team looked at Orchestia gammarellus, a type of amphipod that grows up to about 1.8 centimeters in length. Living in a wide range of habitats such as shallow waters, the intertidal zone, and in estuaries, the amphipod can be found in Norway and Iceland, coastal waters of Europe, all the way down to southwest Africa.
When the team observed the Orchestia gammarellus shredding a plastic bag into the microscopic microplastic parts, they realized that the amphipods were contributing to the spread of microplastics within the marine environment, rather than them simply being emitted from the water supply or forming through the physical and chemical break down of larger items.
The study’s concept was to determine if different types of plastic and the presence of a biofilm (a layer of organic material which accumulates over time) could change the rate at which such organisms broke down plastic debris.
The researchers monitored shorelines and its lab, recognizing that plastic bags were stretched and then torn by the Orchestia gammarellus… and proof that the plastic was being consumed when its fecal matter contained microplastics.
The study found that it didn’t matter on the type of plastic: conventional, degradable, biodegradable… the Orchestia gammarellus tore it apart with equal voracity. Biofilm, however, was torn apart four times quicker.
Previous studies led by the university have shown that more than 700 species of marine life have been found to have encountered plastic debris, with clear evidence that ingestion and entanglement causes direct harm to many individuals.
The full study – Ingestion and fragmentation of plastic carrier bags by the amphipod Orchestia gammarellus: Effects of plastic type and fouling load by D.J. Hodgson, A.L. Bréchon, and R.C. Thompson – is published in Marine Pollution Bulletin, https://doi.org/10.1016/j.marpolbul.2017.11.057.
Image above shows a group of Orchestia gammarellus found under a rock. Image by Auguste Le Roux via Wikipedia.