Scientists Find Majority of Hermit Crab Species Have Used Trash as Shells

Those who remember their nature classes from school will recall that the hermit crab is a fascinating creature. A member of the crustacean group of invertebrates, these crabs comb the ocean floor looking for a new home.

Hermit crabs scavenge, looking for discarded shells to provide shelter and protect their fragile exoskeleton. It’s a fascinating process, but the crab’s instinct could be their downfall in the face of a modern, artificial phenomenon.

Any Home Will Do

At the University of Warsaw in Poland, researchers have looked into the issue of hermit crabs using plastic and metal waste as shells. The scientists have studied around 29,000 online images of these creatures and their makeshift protection.

The findings first appeared in the Science of the Total Environment journal, suggesting that the crabs gravitate toward soda bottle caps. These account for almost 85% of those images and appear a better fit for the animal’s body.

The crabs have also used other plastic items, while some have employed metal caps and even a piece of light bulb.

Adapt to Survive

The habits of hermit crabs could be seen as a form of modern evolution. In other animal species, there have been changes to physical structure as the creatures adapt to their surroundings.

The fox is a predator in the wild, but its urban counterpart has to scavenge for its food. Urban foxes have smaller snouts and greater biting strength, which is one of many ways modern evolution works.

Similarly, the hermit crab is adapting, but will it survive, or will the trend for plastic shells spell disaster for the species?

Damage Done

Images of hermit crabs using plastic caps as makeshift shells may look comical, but the situation is not a laughing matter. That unintentional “comedy” should also be concerning, as anyone entertained by those pictures will not see them as a deterrent.

The scientists in the study declared that they were “heartbroken,” and that’s the appropriate reaction in this situation.

Speaking to BBC Radio 4’s Inside Science, Professor Marta Szulin said, “When I first saw these pictures, I felt it was heartbreaking. At the same time, I think we really need to understand the fact that we are living in a different era, and animals are making use of what’s available to them.”

Professor Szulin added that snail shells are becoming scarce, so the hermit crab is using plastic out of necessity rather than choice. She also suggested that the lighter weight involved with plastic might help smaller and weaker creatures survive.

From here, the study will go on to establish whether plastic is having a detrimental effect on the hermit crabs’ wellbeing. The pictures are shocking, and the study is concerning, but while plastic in our oceans grows, has this iconic crab found a way to adapt?

The studies continue, but at least these beautiful creatures are teaching humans a lesson in recycling. We can only hope that it isn’t to their detriment.