A geoduck, pronounced “gooey-duck,” is an exceptionally large, edible saltwater clam known for its unusual appearance. Native to the Pacific Northwest, this bivalve mollusk stands out due to its disproportionately long siphon, which extends far beyond its shell. Recognized as the world’s largest burrowing clam.
Unique Characteristics and Habitat
The geoduck possesses distinctive physical features. Its shell typically measures 15-20 centimeters (6-8 inches) in length, yet its extensive siphon can stretch up to 1 meter (3.3 feet) or more. This large siphon, often described as an “elephant trunk,” cannot fully retract into its relatively small shell. An adult geoduck typically weighs 0.9-1.1 kilograms (2-2.5 pounds), though some can exceed 4.5 kilograms (10 pounds).
These clams thrive in soft sediments like mud, sand, or pea gravel along the Pacific Northwest coast, from Alaska to Baja California, Mexico. They burrow deep into the seabed, to depths of 0.9-1 meter (3-3.4 feet), and are found from shallow intertidal zones to subtidal waters exceeding 100 meters (300 feet). The geoduck feeds by extending its siphon to the surface, drawing in water containing phytoplankton and nutrients, and then expelling filtered water.
Harvesting and Longevity
Harvesting geoducks involves specialized techniques due to their deep burrowing nature. Divers typically use high-pressure water jets to loosen the sediment around the clam, allowing them to extract the mollusk without damaging its siphon. This precise method minimizes by-catch, distinguishing it from other fishing practices. While most geoducks are wild-harvested, there is also a growing aquaculture industry, particularly in Washington State, where clams are grown in tidal flats using net-covered tubes.
Geoducks are known for their extraordinary lifespan, making them one of the longest-living animals. Many individuals live over 100 years, with some reaching 179 years. Their longevity is attributed to deep burrowing, which protects them from most predators, and a slow metabolic rate. Shell rings can be analyzed to determine their age, similar to tree rings, providing insights into past marine conditions.
Culinary Applications and Market Value
Geoducks are a prized delicacy, particularly in Asian cuisine, including regions like China, Hong Kong, Japan, and Korea. Their unique texture is crisp and tender, especially the siphon, while the flavor is mild, sweet, and subtly briny, reminiscent of fresh seawater. It can be prepared in various ways, commonly served raw as sashimi or crudo, or lightly cooked in dishes such as stir-fries, hot pots, and soups.
The demand for geoduck has established it as a high-value seafood commodity. It often commands significant prices, with live specimens selling for $20-$150 per pound, depending on market conditions and origin. This high market value is driven by its status as a luxury item, particularly in international markets where it is viewed as a symbol of prestige. The majority of geoduck exports from the United States and Canada are sent to China and Hong Kong, highlighting its economic importance.