Several geoducks in water

The Most Interesting Facts About Geoduck (Gooey Duck)

A geoduck or gooey duck is a filter feeder and the largest known clam. Usually, this bivalve mollusk has a long siphon and a small shell. A geoduck is unlike other clams because adults cannot retreat into their shells if threatened. As a result, it leaves their siphon exposed to predators such as starfish, dogfish, sea otters, and crabs.

This giant clam is known as Panopea generosa. Even so, people use names such as geoduck, gooey duck, king clam, goeduck, gweduck, giant clam, and elephant-trunk clam to refer to it. In Japan, a geoduck is known as mirugai (giant clam) or mirukuigai.

These giant clams may appear unappealing to the eye. However, they are a rare and expensive delicacy in Asia. Japan, China, and Hong Kong are the largest markets for geoducks. You can buy these bivalve mollusks in seafood markets or restaurants. However, access varies across regions.

Puget Sound is home to millions of geoduck clams, both in the wild and on large commercial farms. There is also an abundant supply in Alaska, Washington, and British Columbia. In addition, Northwest Mexico and Baja California have huge stocks. Japan, New Zealand, and Patagonia also have stocks of related species. However, their geoduck clams appear smaller than those in Pacific Northwest.

Why Do Geoducks Squirt Water?

Geoducks squirt water to expel seawater and other waste, taken into the siphon to obtain nutrients. Usually, these giant clams suck water through one chamber of their long siphon and force it out once the gills filter oxygen and plankton. Squirting water allows a geoduck to draw more water into the chamber and filter more food.

A geoduck opening siphon to squirt water
Geoduck? Piddock? by pfly

Why Are Geoducks An Expensive And A Rare Treat?

The highest-grade geoduck clams cost about $25 per pound. However, the price can go down for low-grade geoducks. Geoducks can also fetch as high as $150 per pound for premium quality harvest but only in isolated cases. The same top-grade geoduck will cost 2-3 times more in a restaurant. This huge price difference leaves you with a big choice on whether to go for a home-cooked or restaurant-prepared geoduck.

Time to marketable quality

Geoducks are expensive and rare because they take a long time to grow and reach an ideal weight of about 2 pounds. They usually take six years to achieve marketable quality. The much bigger gooey ducks take more time to grow. They may require up to 15 years to reach their maximum size. At this point, they may weigh as high as 7 pounds.

Predator attack

Geoducks are also prone to predator attacks. The larval or juvenile stage appears most susceptible to these attacks. As a result, a significant percentage do not reach the market, and the fewer that reach marketable quality cost more.

High demand and low supply

There is also growing demand for geoducks globally. The high demand and government restrictions on harvesting in natural habitats have led to a supply issue. As a result, geoducks have become rare and more expensive. This development has also fueled the growth of commercial geoduck farms.

The government usually does not regulate the harvesting of farm-raised geoducks. Unlike wild geoduck stocks, geoduck farms can harvest anytime, which improves supply. However, this might affect the sustainability of farmed geoducks, as there is no follow-up on whether geoduck farms adhere to the provisions of the Endangered Species Act.

Unique Health Benefits of Geoducks

Geoducks have a high protein content. A single serving can provide about 13-15 grams of protein.

Geoducks also have a total fat content of 2 grams. Polyunsaturated and monounsaturated fatty acids make up the highest percentage of this fat. A serving of geoduck clam contains omega-3 fatty acids. However, these fats occur in higher quantities than omega-6 fatty acids. Omega-3 and omega-6 fats help boost good cholesterol levels and reduce bad cholesterol in the body. As a result, they promote heart health and help regulate blood pressure. Thus, eating geoducks can guard against hypertension and cardiovascular diseases.

Geoducks are also rich in potassium and phosphorous. Phosphorous helps build strong bones and keep teeth healthy. It also promotes muscle health and improves kidney function. By contrast, potassium helps regulate blood pressure and protects against heart disease.

Geoducks are also a good source of calcium and vitamin D. This mineral helps keep bones and muscles strong. As a result, it promotes better heart, nerve, and muscle function. Also, calcium and vitamin D help prevent cancer, hypertension, and diabetes.

Geoducks are also good sources of iron. The iron content is sufficient enough to almost meet the recommended dietary intake. This nutrient boosts red blood cell production and keeps the immune system strong.

In addition, geoduck clams contain vitamin E, niacin, riboflavin, choline, A, B6, and folate. It also supplies pantothenic acid, vitamin B12, and vitamin B6. These nutrients occur in relatively low quantities. Even so, they work together to promote good health.

How to Prepare and Eat Geoduck

The most used cooking techniques for geoduck include frying, boiling, and sauteing. However, you can serve raw geoduck meat as sashimi. Geoduck is also used in sushi. Its robust flavor, sweet taste, and crisp texture make it perfect for sushi.

Geoduck ceviche in a plate
Hamachi, geoduck ceviche by T.Tseng

Tips for Preparing and Cooking a Geoduck

  • Wash the geoduck thoroughly using tap water to remove sand and mud
  • Blanch in boiling water for about 10-20 seconds
  • Remove the geoduck clam and put it in an ice bath
  • Pull the shell out and extract the belly meat
  • Peel off the outer skin
  • Split the siphon lengthwise into two halves
  • Chop the meat into paper-thin slices
  • Serve as sashimi
  • Alternatively, stir fry briefly with olive oil, chili, lemon juice, mint, and salt.
  • If you want to lighten a dark siphon tip, rub it with sea salt and rinse
  • Preserve geoduck stomach (a large ball visible after removing the shell) for chowder
  • Avoid cooking for long periods (it makes the meat tough)

What Does a Geoduck Taste Like?

The belly meat tastes sweet with a salty or fresh sea flavor. It is also more tender and good for sushi and sashimi. However, the neck has a crunchy texture. It is also a little tough. However, cooking gooey duck for a short period and cutting it into paper-thin slices makes it easy to chew.

Are Geoduck Clams Safe to Eat?

Geoducks are safe to eat. However, there have been isolated cases of geoduck shipments contaminated with shellfish toxins. Inorganic arsenic is another contaminant that might affect the safety of geoducks. However, relevant authorities closely monitor these contaminants to ensure the harvest is safe for human consumption.