Meeting Abstract
Hermit crabs use a variety of found objects (bamboo, shells, plastic) as housing. Humans are discarding more materials that are finding their way into our waterways. On Cayos Cochinos, land hermit crabs (Coenobita clypeatus) commonly incorporate plastic objects into their “shell supply” chain. Over the past 15 years, our research has shown that there is an increase in use of plastic (wine bottle plugs, PVC pieces, furniture knobs, bottles) as well as other materials (empty shotgun shells, glass fuse covers, glass bottles) into their resource pools. Larger shells on this island are not found frequently as shell accumulation sites. Hermit crabs may be using these alternative resources as a substitute for larger shells, in particular. However, we have noted that hermit crabs of all sizes have been collected using found objects from human (foh)sources into the shell pool. Despite augmenting shells on the island, we have found that 1) there has not been an significant increase in population size and 2) there has not been a decrease in use of found objects from humans. When provided shells at accumulation sites, crabs readily switch from their foh into shells, suggesting that shells remain a scarce resource for these land crabs and that shells are preferred over the fohs. Crabs in fohs do produce clutches, as noted for a few crabs over the past couple of years. However, the overall impact of using fohs is still under investigation.
