Saving Shells

by Janine Licare, Founder and Spokesperson KSTR

The art of shell collecting dates back thousands of years.  Over time, shells have been used as currency, treasures and game pieces to different civilizations. In present times, shell collecting has led to the birth of conchologists, malacologists, among other words rarely used in the English language. The OCD reaction some might have towards picking up shells and storing them on their balcony or in vases in their living room is leading to a shortage in adequate sized homes for small sea creatures. Shells provide shelter to invertebrate animals with no mechanism of protection or self-defense.  Every so often these creatures trade homes depending on how fast they out-grow their current homes. Those beautiful shells you keep on your shelves are actually the dead carcasses of sea creatures. When clams, oysters, starfish and mollusks die, their shells wash up on the beach with the tides and are taken as a shelter to those who do not have the mechanisms to create them themselves.

The art of shell collecting and the mortgage crisis in the US are two very distinct events that don’t run too far from home. They share more similarities than Palin and McCain and resemble an issue neither one of them could solve. The economic crisis that has been affecting millions of families in the US for the past year, causing people to lose their homes, is just as much an issue for hermit crabs and similar creatures.  It has been suggested that hermit crabs are on the verge of becoming in danger of extinction due to the destruction and loss of their habitats, stemmed by shell collectors and the loss of their homes. Shells are made by the excretion of calcium around the animal. Almost all genera of hermit crabs use or “wear” empty marine gastropod shells throughout their lifespan in order to have a strong shell to withdraw into if attacked by a predator. Each individual hermit crab is forced to find another gastropod shell on a regular basis; whenever it grows too large for the one it is currently using. Since suitable intact gastropod shells are a limited resource, there is frequently a heavy competition among hermit crabs for the best available shells. The availability of empty shells depends on the relative abundance of gastropods in the right range of sizes, as well as the frequency with which shells are collected by humans in the region.

Shells are indispensable to the survival of certain species because most species of hermit crabs have long soft abdomens which naturally have no form of self-protection. They obtain protection by the adaptation of carrying around a salvaged empty seashell into which the whole crab’s body can retract. As the hermit crab grows in size, it has to find a larger shell and abandon the previous one. The shells used by hermit crabs originally come from mollusks which possess a fleshy mantle. They use this mantle to produce a shell by absorbing sodium carbonate and other ingredients from their habitat and food and secreting it in an orderly fashion to form a shell house.  It is not terrible to collect shells, just do it in moderation.  More and more shells are created as new animals are created to be used as protection, but nonetheless, you never know if the shell you pick up today could have been the perfect home for another creature tomorrow.