A new study says tourists who are taking seemingly abandoned seashells home from vacation are harming natural habitats and damaging the natural ecosystem.
Researchers from the U.S. and Spain said 70% of mollusk shells disappeared from beaches on the Mediterranean coast of Spain in July and August, up 10% from the 60% decrease seen in other months. The shells are not particularly nice to look at and were not uncommon, but are likely just picked up by shell collectors, the study said.
"It's too early to tell whether this depletion is substantial enough to trigger major environmental changes. However, our results suggest that we should not ignore this issue," researcher Michal Kowalewski said in a release about the study, which was published in the journal PLOS ONE.
Geerat Vermeij, a mollusk shell expert who was not involved in the study, said the shells are of prime importance to hermit crabs, and many small organisms tend to settle on dead shells.