By Mia Davidson and Jan Sattler
Numerous sea shells, naturally deposited by the tides, can be found along the shore of Laguna Beach. Shells are the hard protective coverings formed by many marine invertebrates, animals lacking a backbone. Though shells may be familiar, the animals that create them frequently are not.
One of the most impressive shells often found in Laguna is the wavy top turban shell (Megastraea undosa). The color of this spiraling shell is a reddish-brown to dark gray that erodes to a pearly white as the shell is rubbed across the sand by water movement. The heavy shell can reach up to six inches in diameter and is the largest gastropod in California. When alive, the wavy top turbans are slow moving herbivores that feed mostly on kelp and coralline algae, living on the rocks in the low intertidal zone and in depths up to 60 feet. When the snail retracts into its shell, a tear-drop shaped trap door, known as calciferous operculum, seals the opening of the shell to protect the gastropod inside. The maximum lifespan of the wavy top turban is estimated to reach 12 years. Predators include sea stars, Kellet’s Whelks, octopi, lobsters and fish.
Opportunities for shell observation are numerous along the 7.5 miles of Laguna’s coast. They are an important coastal resource that provide habitat to other living organisms and help replenish the marine environment so they need to be left where they are found. Previously collected shells should not be returned to the ocean environment because they may contain biological material that can harm the ecosystem. If anyone feels compelled to return legally collected shells, they may be dropped off at Marine Safety Headquarters on Main Beach where they will be incorporated into the tidepool education programs. Laguna Beach is either a state marine reserve or a no-take state marine conservation area, thus there is absolutely no collecting of shells permitted.
Mia Davidson and Jan Sattler are residents of Laguna Beach, year-round ocean swimmers and board members of Laguna Ocean Foundation. Its mission is to preserve and protect the beaches, intertidal zone, watersheds, and ocean waters of Laguna Beach and to educate the public about these resources. For more information, go to www.lagunaoceanfoundation.org