Bivalve molluscs, such as snails and clams, are a very thin, so they need protection from the elements and from predators. Seafood is developed in the ocean, love the tissue will absorb the salt and the elements. They secrete calcium carbonate, which hardens the outside of the body, creating a strong backing. The zinc remains to be the seafood, but in fact, it is not a part of his living body, which is composed of the minerals, cells, unlike most of the animals of the structures). The seafood will continue to absorb the salt and marine chemicals, and to release calcium, causing it to drop even further. When a clam dies, it sheds its shell, which eventually washes ashore. Here is the idea of going to the beach.