Fish eat plastic in the ocean because it smells like food, scientists discover


Fish eat plastic in the ocean because it smells like food, scientists discover

The reason why fish eat plastic when it is dumped in the ocean has been discovered by scientists.

Tests on anchovies show that when plastic is mixed with salt water and begins to disintegrate it releases an odour which is similar to krill.

The enticing smell sets of foraging and feeding behaviour in fish, causing them to eat the debris, believing it is food.

Previously scientists thought that fish were ingesting tiny particles of plastic by accident when they were hoovering up floating pieces of plankton or krill. But the new study suggests the problem is even more serious, because fish are actually attracted to the plastic.
Writing in the Proceedings of the Royal Society B, first author Dr Matthew Savoca of the University of California and the US government’s National Oceanic and Atmospheric Administration, said: “These results demonstrate that odours associated with plastic debris stimulate a behavioural response consistent with foraging in captive anchovy schools.

“As when foraging, the anchovy responded to the medium and high concentrations of biofouled plastic odour. Similar results were seen in response to all concentrations of food odour, thus indicating anchovy use odours to initiate foraging behaviours.


“This is the first behavioural evidence that plastic debris may be chemically attractive to marine consumers. These chemical cues may lure consumers, such as anchovy, into regions of high plastic density and activate foraging behaviours.”

“These findings have considerable implications for aquatic food webs and possibly human health.”
To come to the conclusion scientists concocted a watery mixture of krill, and a second solution of broken down plastic. They then added it to a tank of anchovies to see their reaction. High levels of plastic set off the same foraging behaviour as krill, although smaller amounts were ignored by the animals.

Experts have calculated that by 2050 the world’s oceans will contain more plastics than fish, by weight.

A recent study estimated that nine in 10 of the world’s seabirds now have pieces of plastic in their guts, mainly through eating fish which have ingested plastic.

A recent study by the University of Ghent in Belgium found human seafood eaters ingest up to 11,000 tiny pieces of plastic every year with dozens of particles becoming embedded in tissues.

If current trends continue, by the end of the century people who regularly eat seafood could be consuming 780,000 pieces of plastic a year, absorbing 4,000 of them from their digestive systems.


There are more than five trillion pieces of microplastic in the world's oceans and the equivalent of one rubbish truck of plastic waste is being added to the sea every minute.
By 2050 that will increase to four trucks every minute.

Speaking at the launch of a new campaign by Sky Ocean Rescue to encourage people to recycle more plastic British explorer Sir Ranulph Fiennes said: “I’ve explored some of the most remote and vast points of the world and yet still witnessed the reach of ocean pollution.


“Between 1979 and 1982 my team completed the first surface circumpolar navigation of Earth and during both the Atlantic and the Pacific voyages we witnessed the amount of pollution, much of which was plastic and that was just on the surface. 

“It is vital that we all take action to protect our oceans and we must act now before the scale of this problem heightens further. Simple changes to everyday life are easy to do and give us the chance to prevent further damage.


“We all use plastic but we have to think beyond ourselves and save our beautiful and important seas. I’m pledging my support and hope others will follow.”

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