Share

Panopea generosa

Geoduck-Plate
Panopea generosa (Geoduck)

By appearance the Panopea generosa otherwise known as the Pacific Geoduck (Gooey-duck) might not be the most settling thing to see, and especially if it is your first time. However, it has had a profound impact on the Klahoose First Nation over the past few years. The Klahoose First Nation is one of the first nations in B.C. to have their own tenure. With years of work and negotiation with Department of Fisheries and Oceans (DFO) to attain the tenure, Klahoose had successfully conducted its first harvest this year. The majority of the market was overseas – particularly in China and Hong Kong, where it is considered a delicacy. Although China has been the leading market thus far the Pacific Geoduck’s reputation is expanding to seafood lovers across the world for its fresh taste. Pacific Geoducks are marine bivalve mollusks native to the west coast of North America. In other words, they are a large edible salt water clams that live the majority of its life on the ocean floor mostly underwater. The Pacific Geoducks overall have a great reputation around the world because of the clean salt waters of the coast. The coast’s environment gives the species a special fresh flavour and has a variety of sweetness with a satisfying crunch as well (Underwater Harvesters Association, 2014).

Lifecycle

Pacific Geoducks are broadcast spawners and have two different sexes. Broadcasting spawing is one of the most common methods of reproduction in the sea. It is also known as mass spawning or synchronous spawning. The animals release their eggs and sperm into the water and fertilization happens externally (Paleontological Research Institution, 2012). During this time the females release anywhere from 7 to 10 million eggs. Within the first 48 hours, shelled larvae begin swimming around the spawning ground. In a few weeks’ time the geoducks develop a tiny foot at the bottom of their bodies and drop to the ocean floor. There is no specific environment where the geoducks live on the coast, so it can either be in the mud or gravel, however the appearance of the species varies with each environment in which it grows. The differences can be in colour and size (Underwater Harvesters Association, 2014).

Once they drop down to the ocean floor usually in depths of 20-50 ft below the surface, they dig into the ground and remain there for the rest of their life. Over the next few years their shell hardens and their bodies fully develop. Once full grown the shell sizes vary from 15cm (5.9 inches) to over 20cm (7.9 inches). They are the largest burrowing clams in the world with an average weight of 1.5 pounds, and some have weighed in at 15 pounds. The siphon, which is sometimes referred to as its “neck” or when loosely translated in Chinese “elephant trunk” protrudes the shell and can grow up to 1 metre long! It is called an “elephant trunk” in China because when preparing the geoduck for a dish, the siphon has two main valves that filter saltwater in and out of its body for plankton. The outside body and these valves distinctly resemble an elephant trunk. Pacific Geoducks are one of the longest living animals on the planet with a lifespan up to 140 years and the oldest recorded living species was 168 years old. Their longevity is largely due to having no serious natural predators. Another contributing factor is their ability to bury themselves extremely quickly up to 1 metre deep (Underwater Harvesters Association, 2014). Similar to counting the age of a tree their age can be roughly determined by the growth rings on their shell. The Pacific Geoduck is popularly known in Canada as the “King Clam” due to its size and prestigious reputation.

Harvesting

When a Geoduck is harvested at low tide the person who is harvesting the animal has a special pump similar to a ghost shrimp pump in his or her hand and grabs the geoduck at the top of the siphon. As the geoducks burrows down into the mud the person harvesting hangs onto the geoduck with their hand and sending the pump down with it flushing out surfaces for the geoduck to dig. As the harvestor follows the specimen they often have to stick their entire arm in the mud before the geoduck releases its grip – so they literally have to lie flat on their side before they can bring it up. After the geoducks have been taken from the mud, rubber bands are placed around the shell to it into place for transport. This done because they are quite fragile and can fall apart easily. Another method of harvesting is to have a diver go down into the water and harvest them individually in a similar manner.

When new things come into our life the best thing to do is pass the knowledge onto the next generation. The Cortes Island School’s primary class to came to see a live geoduck for themselves and even eat one! After drumming ceremony by Stanley, Randy and Rosemary and official cultural welcome by elders Rose and Marj Hanson the kids were eager to go down to the beach. The kids were not only intrigued by the geoducks and other live specimens, but were searching the beach looking for beach glass and other treasures to trade amongst each other. A successful day full of learning and fun. Thank you to everyone that helped with the field trip.

Works Cited

Paleontological Research Institution. (2012, December). Broadcast Spawning. Retrieved May 24, 2017, from Priweb: https://www.priweb.org/outreach.php?page=Edu_Prog/s_us_home/s_us_lifestyles/s_us_broadcast-spawning

Underwater Harvesters Association. (2014). Geoduck from Canada. Retrieved May 24, 2017, from geoduck.org: http://www.geoduck.org/about.html#wrap