Plastic mosquitoes could threaten animal food chains

Mosquito larvae grow in water often polluted by plastics – and they could bring this plastic into adulthood.

Researchers at the University of Reading investigated whether microplastics in the water ended up flying with mosquitoes. Published in Biology Letters Wednesday, the study showed that water pollution can lead to pollution in uncontaminated areas.

"We were expecting them to eat plastic," said Amanda Callaghan, a professor at the University of Reading and author of the study. Newsweek. Mosquito larvae can not distinguish between food and plastics at this age. "What we did not expect was that so much of the plastic went to the next stage of development."

In the lab, the team fed 150 mosquito larvae, a mixture of microplastic beads of different size and food. Mosquitoes are not able to break plastics in their stomachs. They then selected 15 random individuals to examine at the larval stage and a group other than 15 when they were adult mosquitoes capable of flying.

In each mosquito, the team found microplastics, small pieces of plastic less than 5 millimeters. Even though mosquitoes have matured, they have stopped eating plastics. The team found an average of 40 microplastic beads in each of the adults.

This could mean that when animals that live on the land, such as birds, bats or spiders, eat adult mosquitoes, these animals will also eat the plastics inside the mosquito bodies. .

"For larger animals, plastics can block their bowels. Plastics can have unpleasant chemicals stuck to the surface and concentrating on plastic, and then exposing animals to more concentrated chemicals, "said Callaghan. Plastics do not only affect the larger animals that eat mosquitoes.

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Plastic garbage on the beach of the Aegean Sea near Athens. Mosquito larvae in the water feed on plastics and bring them into adulthood. MILOS BICANSKI / GETTY IMAGES

"The problem is that they are bioaccumulative," said Callaghan. "So, the more animals there are in the food chain that contain plastics, they will be eaten by something else, which is eaten by something else, so there will be a time when there will be plastic loads quite high. " More than 8 million tons of plastic enter the ocean every year, according to the 2015 Science study, the amount of plastic in terrestrial creatures could be added.

Callaghan said that mosquitoes are unlikely to transfer microplastics to humans, as they would with infectious diseases such as malaria, unless the plastics are in the salivary glands. They did not see any traces of plastic in the mosquitoes' heads.