Plastics are ruining the guts of seabirds.

This may be why her team found the opposite results in their analysis: more Individual The microplastics in the intestine, the more diversity of microorganisms, but it is higher Mass Microplastic, the difference is low. The richer a bird is, the more likely it is that those wonderful microbes will be introduced to its gut. But if the bird eats a lot of microplastics — smaller, but heavier pieces — it may have eaten fewer microbes from the outside world.

Meanwhile, particularly porous microplastics can scratch the digestive system of birds, causing damage to the microbiome. In fact, the authors of the plasticosis paper found significant damage to the guts of wild carnivores living off the coasts of Australia and New Zealand, birds that ate microplastics and macroplastics. (They also looked at plastic particles of about 1 millimeter) “Plastic, when you ingest small amounts of plastic, it changes the structure of the gut, often very, very significantly,” said the study’s author Jennifer Lavers, a pollution ecologist. At the Adrift Lab, he researches the impact of plastic on marine life.

In particular, the birds’ tubular glands, which produce mucus to act as a protective barrier for the lining of the stomach and hydrochloric acid to digest food, were severely damaged. Without these key nutrients, birds “can’t digest and absorb the proteins and other nutrients that keep us healthy and fit,” Lavers says. Therefore, you are vulnerable and exposed to other bacteria, viruses and pathogens.

Scientists call this the “nonsense effect.” Although the pieces of plastic that get inside do not kill the bird immediately, they can seriously injure it. Lavers calls it a “one-two punch of plastic,” because eating the material actually harms the birds, making them more vulnerable to the pathogens they carry.

A big caveat to today’s paper — and most microplastics research — is that most scientists aren’t analyzing the smallest plastic particles. But researchers using special equipment have recently been able to identify and quantify nanoPlastics, on a scale of millions per meter. These are many and many in the area. (Finding that there is about 11 billion pounds of plastic on the ocean floor is probably an overestimate because this team was only thinking about particles down to a third of a millimeter. And dear, so Fakelman’s team wondered how much of it could be in the digestive systems of seabirds and It cannot say how they affect the microbiome.

It can’t be good news. Nanoplastics are so small that they can penetrate and damage individual cells. Experiments on fish have shown that if you feed them nanoplastics, the particles can enter their brains and cause damage. Other animal studies have shown that nanoplastics pass through the intestinal barrier and are transported to other organs. In fact, another paper published in January even found Lavers MicroPlastic kidneys and splints on meat legs where they cause serious damage. “The damage we showed in the plasticity paper may be conservative because we didn’t encounter particles in the nanoplastic spectrum,” Lavers said. “I personally think this is very scary because the damage to the plastic sheet is very serious.”

Now, scientists are scrambling to find out whether the plastics that are ingested can endanger not just individual animals, but entire populations. “This damage at the individual level – all these different micro-effects, exposure to chemicals, exposure to changes in the microbiome, plasticosis – is it enough to reduce the population?” asks Lavers.

Scientists don’t have enough evidence to form a consensus, so the jury is still out on that. But Lavers believes in the precautionary principle. “A lot of the evidence we have now is very worrying,” she says. “I think we have to let logic prevail and make a fairly safe and conservative estimate that plastics are currently causing population declines in some species.”