Recently, a group of Spanish researchers described for the first time scientific observations of ants entangled in plastic fibers.
This is the first systematic and scientific description of the effects of synthetic fibers observed by multiple entomologists and expands our knowledge of the extent of microplastics and their potential impacts on living organisms and ecosystems.
It is becoming increasingly clear that plastic pollution is almost ubiquitous. Microplastics have been detected in seawater, Antarctic ice, the atmosphere, rain, plants, animals and even human organs and blood. The two most common forms of plastic are plastic particles and fibers.
Particles are more likely to enter the food web and accumulate in living organisms. The largest ones can penetrate the body of animals, and the smallest, microscopic ones, enter plant cells through the roots.
On the other hand, the fibers, although present in smaller proportions, have a more noticeable effect, especially on fauna, because they become entangled.
Tangles are most often found on the gills of fish or, more commonly, on the feet of sparrows, pigeons and other birds, especially those that live in urban areas. The same is observed in sharks, turtles and marine mammals.
Getting caught in plastic, with serious and even fatal consequences, is one of the biggest dangers associated with this type of pollution.
But just like plastic particles, there are also fibers in many different sizes. The largest can attack vertebrates, making it difficult for them to move and function, while the smallest have the same effect on insects and other invertebrates.
Ants get caught in plastic fibers
Recently, a group of Spanish researchers described for the first time scientific observations of insects, particularly ants, becoming entangled in plastic fibers.
The research team consisted of Álvaro Luna, professor at the European University of Madrid and author of “The World of Plastic”; J. Manuel Vidal-Cordero from the Doñana Biological Station (EBD-CSIC), author of the book “Las Hormigas”; and Armand Rowsell-Moreno, winner of the 2022 GBIF Young Researcher Award. The research was published in the journal Ecological Entomology.
Field work was carried out on the island of La Palma in the first half of May 2022. They collected samples from 40 different locations covering a large portion of the island’s habitat, lifted rocks or pieces of dead wood to test for the presence of ants in ant nests, and then collected the individuals as they foraged for food.
However, to prepare the sample it was necessary to collect it very carefully to avoid contamination. In the presence of microplastics, traditional insect collection methods such as: B. suction can cause loose fibers to get into the collected sample and subsequently lead to incorrect and distorted results.
In addition, any thread that sticks to the researcher’s skin or comes off his clothing jeopardizes the examination.
Therefore, the scientists used a sampling method that minimizes contact with the ants and the risk of infection.
Once they found the ant, they placed a small sample container – an Eppendorf tube – with the lid open and stopped its path directly in front of them. Most ants enter the tube alone in search of food.
The sample was then preserved in ethanol and sealed.
Ants get caught in plastic
Only 113 people were captured in 40 locations. Three of them were entangled in synthetic fibers, an initial impression that was later confirmed in two cases by laboratory analysis. At first glance, these data seem very sparse, a very small sample as the researchers admit, but they are important nonetheless.
One aspect that must be taken into account is that passive collection of ants allows only those that are alive and have sufficient mobility to be collected in the Eppendorf tube. An ant that was unable to move was not caught, so the sample may have underestimated the problem.
Entangled ants can be created accidentally when foraging for food and coming into contact with fibers. However, the authors acknowledge that they can arise from disorientation if the ant thinks it has been eaten or collected as potential building material.
Researchers cannot rule out that the effect of tangled wart ants is much more widespread than this small scientific report suggests.
After the report on this discovery in September 2023 at the VI. At the International Congress on Nature Conservation and Biodiversity in Huelva, several entomologists told the authors that they had found ants entangled in synthetic fibers, including Dr. Vidal Cordero. This was observed in previous research in southern Spain.
This study is the first scientific report of an event apparently known to mycologists.
A new way to study the effects of microplastics
Most studies on the presence of microplastics in soil have been conducted in agricultural areas. However, in this study, the ants were collected in natural environments without human influence. In particular, one of the entangled ants was caught in an area of gorse scrub, a protected species endemic to the islands of La Palma and Tenerife, one of the island’s least altered landscapes, albeit with a certain influx of tourists.
According to the authors, proximity to roads could be the source of these pollutants, which serve as a means for these materials to spread. However, research shows that plastic pollution poses a widespread threat to terrestrial ecosystems that goes far beyond what is commonly understood and, in many cases, overlooked or ignored.
Although no immediate damage to the ants was documented in the study, the possibility of long-term negative consequences for both the individuals directly affected and their entire ecosystem cannot be ruled out. These include changes in natural behavior, impacts on invertebrate health, and changes in ecosystem dynamics due to altered ecological interactions.
Scientists recognize that it is important to conduct more research to assess how often ants and other land invertebrates become entangled in plastic and to understand the ecological consequences of these encounters.
This research needs to be expanded across multiple different habitats and geographic areas to gain a comprehensive understanding of the extent and impact of plastic pollution on terrestrial ecosystems.
This article was written by Dr. J. Manuel Vidal-Cordero, co-author of the study, reviewed.
References:
- Luna, A. et al. 2024. Plastics and Insects: Records of Ants Entangled in Synthetic Fibers. Ecological Entomology, 49(1), 145-148. DOI: 10.1111/een.13284
- Rausell-Moreno, A. et al. 2023. What’s wrong with the ants on La Palma? DOI: 10.13140/RG.2.2.17957.47844
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