Hermit Crabs 'Excited by Plastic Pollution' Amid Their Usage of Trash as Shells for Protection [Study]

Hermit crabs have been observed by scientists to be using trash or plastic waste as shells for protection and shelter. These findings are according to a new study led by experts in Poland, who found that the majority of land hermit crab species worldwide are squeezing themselves inside a variety of artificial marine waste such as plastic materials, ranging from pipes to plastic scoops, bottles, and LEGO bricks.

The 'hermit crab plastic shell' phenomenon also made its way on the internet, showing the different kinds of trash the crustaceans are using to go underneath. Bizarre as it may seem, these events are causing concerns among the scientific community since hermit crabs typically use empty mollusk shells to protect their bodies, described as fragile exoskeletons.

The said study, which utilized online data sources (including images posted online), identified hundreds of terrestrial hermit crabs that now use the plastic shells instead of natural shells to cover their exoskeletons. The Poland-based scientists reported that the phenomenon is part of an emerging novel behavior among hermit crabs in the current Anthropocene geological epoch.

Hermit Crab Plastic Shell

Researchers from the University of Warsaw in Poland documented their observations and findings about the hermit crab plastic shell events in their study. It will be published in late February 2024 in the journal Science of The Total Environment. The research paper reports the identification of 386 crabs with artificial shells, accounting for 10 of 16 land hermit crab species globally exhibiting the novel behavior.

The authors of the study posit that there are several factors that drive the behavioral shift in shell choice among the land-dwelling crustaceans, including sexual signaling, shell weight, odor cues, and pollution. The research team also acknowledged that further research is needed to determine the impact of the new behavior on hermit crab evolution.

The online data sources were extracted by the team through internet Ecology (iEcology) as a new tool in ecological research. The Poland university researchers also cited previous research literature and reports to support the framework of their paper. Regardless of the uniqueness surrounding artificial shells, scientists are certain that global plastic pollution is behind the behavioral shift among hermit crabs.

Plastic Pollution Threat

Plastic pollution is a growing environmental and ecological problem in both marine and terrestrial systems on Earth. According to the United Nations Environment Programme (UNEP), an equivalent of 2,000 garbage trucks full of plastic waste are dumped into the world's oceans, lakes, and rivers every day. Annually, 19 million to 23 million tons of plastic debris leak into aquatic ecosystems.

In this context, pollution can change natural habitats and natural processes, UNEP emphasizes. This means that the plastic pollution threat impacts living organisms, such as the case of hermit crabs and their chosen plastic shells, where the researchers describe the animals as being "excited" by the pollution.