1) Don’t take anything that is alive
WHY: This may seem like an obvious one, but these animals are individuals just like you and me, trying to live there lives.
2) Leave Spiral Shells
WHY: Hermit crabs depend on empty spiral shells of all sizes for their survival.
Sure, spiral shells are some of the most beautiful shells you can find. But there is another collector out there who needs them even more than you do: the hermit crab.
There are more than a thousand species of hermit crabs worldwide, and each one of them depends on empty sea shells for survival. Of course you wouldn’t take a spiral shell that already had a living hermit crab in it, but by taking empty spiral shells from the beach you are depriving those same hermit crabs of their next home. As hermit crabs grow, they must move into ever larger shells. If a hermit crab can’t find a larger shell, it will die of exposure or predation.
1) Sea grasses, corals, and anemones often use shells to anchor to the ocean floor.
2) Many creatures like to make their homes on top of dead shells, like slipper shells, barnacles, limpets, and chitons.
3) Some creatures use dead shells to camouflage themselves like sea urchins and the amazing Carrier Shells (called Xenophoridae).
4) Small fish and octopus use discarded shells for cover and shelter.
5) Other organisms burrow into dead shells to survive, including endolithic algae and sponges.
6) Pieces of old shells are used as building materials by a variety of terrestrial animals.
7) Various marine animals use shells as a building material as well. Some marine worms (pictured below) use bits of shell to construct the protective tubes in which they live.
8) Birds, crabs, and many other organisms depend on the remains of washed-up sea creatures for food.