1 Feb 2018 - Scientists have revealed for the first time that our rivers and oceans are so rife with plastic that miniscule particles are penetrating every stage of the food chain.
A new study found tiny ‘nanoplastics’ moving up through all four levels of their freshwater food chain – even penetrating the embryo wall so that they appeared in newly hatched fish.
Researchers also found that the minute particles – less than a billionth of a centimetre wide – damaged the fishes livers and made them lethargic so that they travelled shorter distances and patrolled a smaller area.
The plastic’s journey
The passage of the plastic in the study began when fragments stuck to an algae plant on the bottom rung of the food chain and ended up, via a water flea and a small fish, inside the eco-system’s top predator – the Korean dark chub.
This is an edible fish, indicating that the particles could make one further stop outside the marine ecosystem – at the dinner plate.
“Our findings clearly show that plastic particles are easily transferred through the food chain. And they strongly point to the potential health risks of nanoplastic exposure,” said Professor Youn-Joo An, of Konkuk University in Seoul.
“The presence of nanoplastics in edible fish suggests that they could also be transferred to humans through the same mechanism,” she added.
The new study, by Konkuk University in Seoul, goes much further than previous studies in determining how far plastic can travel along the food chain. Previous research has identified a single transfer between prey and predator.
It comes shortly after separate research found that tiny plastic particles are finding their way into fishes brains and giving them brain damage.
Campaigners said these studies were deeply worrying and underlined the need for dramatic action to stop the flow of plastic into the rivers and oceans – currently a rate of one truckload a minute.
“If polystyrene nanobeads can pass so easily up through the food chain and cause tissue damage and behavioural changes in fish, where do the implications end? Are we also eating nanoplastics?” said Dr David Santillo, a senior Greenpeace scientist based at Exeter University.
“This study gives us a sense of just how pervasive a problem we have created and how impossible it will be to control unless we stop the pollution at source,” he added.
What needs to be done
Dr Sue Kinsey, of the Marine Conservation Society, said: “The research shows the significant problems that plastics can cause to the wildlife in our oceans and highlights the urgent need to act now stop plastics getting into our seas.”
We need concerted action from Governments , industry and the general public to stop this tide of rubbish and need to introduce, as soon as possible, she said.
This should include policies on minimum recycled content for plastic products, taxes on hard to recycle plastics, the banning of polystyrene and black plastic, and the introduction of a deposit refund system for all drinks containers, Dr Kinsey said.