The Olympia Oyster is the smallest oyster in the world and the only one native to the west coast. Once abundant from Alaska to Mexico, Olympia Oysters still inhabit that enormous range but only scattered in small numbers here and there.
A big Olympia is just 3½ inches across. Its light gray shell camouflages it in tidepools and shallow bays. As other oysters, the Olympia sucks in water and sifts out tiny plants and animals for food. Every day it filters 12 gallons, benefitting other animals and marine plants by clearing the water.
Each oyster is male or female but alternates genders during its life. Newborns soon look like tiny adults and drift until finding a hard surface to attach to for the rest of their lives. Because the preferred surface is another oyster shell, oysters can grew into huge layered colonies. These shelter many other small animals that are food for fish, crabs, and other marine creatures.
Olympia oysters taste good and grow slowly, maturing in 5 or 6 years. From the 19th century into the 20th, people harvested them more quickly than the population could replenish. And water pollution ruined oyster habitat. Companies raising oysters to sell found the Pacific oyster from Asia was bigger and faster-growing, so that's the main one farmed in the Pacific Northwest now. Work is underway to restore the native oyster, and some commercial growers raise them.
The decline of the once very common Olympia Oyster shows how important it is to follow shellfish harvest regulations and that controlling pollution is essential for the survival of all marine creatures.