Illustration of Clams

Clams

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Ocean Wise Recommended

Ocean Wise

Variety

Geoduck

Panopea generosa

Method

Farmed

On-bottom culture

Location

Washington State, USA & British Columbia, Canada

Overall Rating

6.1 - 6.2 / 10

Summary

Geoduck aquaculture is an expanding aquaculture industry. Washington produced almost 673mt in 2013 worth almost $28 million, and British Columbia had $2.4 million in sales from farmed geoduck in 2014. Much data and scientific information is available on geoduck production and aquaculture, although more research exploring environmental impacts would be beneficial. There is some concern regarding the cumulative effect of the input of plastic debris and microplastics to the environment from the geoduck farming operations, as well as the long-term impact of the farms. Chemicals such as pesticides, herbicides and antibiotics are not used in geoduck aquaculture, and disease is a rare occurrence on the farms. No external feed is required as geoducks are filter feeders and graze on naturally-occurring phytoplankton for food. This means that geoduck aquaculture does not place stress on wild fish populations for a source of feed. Farmed geoducks can interact with the wild population and there is some concern that genetic differences could negatively affect the wild population. Fortunately, farmed geoduck do not deplete wild geoduck populations for a source of stock, as a single geoduck can produce tens of millions of gametes a year, and can spawn multiple times a year. Therefore only a few individuals are needed to supply the farming operation.

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Ocean Wise Recommended

Ocean Wise

Variety

Razor clam

Siliqua patula

Method

Wild

Hand harvest

Location

Washington, Oregon, Quinault Nation

Overall Rating

3.3 / 5

Summary

The landings of Pacific razor clams have been historically variable due to high exploitation rates and disease. Recently, landings have been increasing. Pacific razor clams are resilient to fishing pressure since they mature quickly. Although overfishing is not thought to be occurring in Oregon and Washington, stock status is unknown. In Quinault, stock status is moderately healthy. Stock assessments are not conducted in Washington and Oregon; however they are conducted in the Quinault Indian Nation. Management is moderately effective in Washington and Oregon, and it is highly effective in Quinault, due to the strict regulations and enforcement.

The hand harvest of Pacific razor clams consists of using shovels or hand tubes. This method can be damaging to the habitat if wave action is not sufficient to redistribute the sediment after harvest. However, minimal amounts of bycatch are caught as hand harvesting is a highly selective fishing method.

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Ocean Wise Recommended

Ocean Wise

Variety

Ocean quahog

Arctica islandica

Method

Wild

Hydraulic dredge

Location

US Atlantic

Overall Rating

3.3 / 5

Summary

Landings of the ocean quahog stock have been variable in the past. Several factors affecting the landings include shifts in the species range, fishery closures due to disease, changes in consumer demand, and increasing fuel prices. Ocean quahogs are among the slowest growing and most long-lived clam species. These life history characteristics make them particularly vulnerable to fishing pressure. Currently, the population is healthy and is not overfished. The stock is well-managed by the Mid-Atlantic Fisheries Management Council. Stock assessments are performed regularly, and regulations are set based on scientific advice. Hydraulic clam dredges are highly selective with little bycatch, but are disturbing to the habitat. They cause the suspension of sediment in the water which increases turbidity, create a trench where the dredge has passed through, change the density and composition of the substrate, reduce the organism diversity in the substrate, and temporarily leave dislodged organisms vulnerable to predation.

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Ocean Wise Recommended

Ocean Wise

Variety

Geoduck

Panopea generosa

Method

Wild

Stinger

Location

British Columbia, Washington

Overall Rating

8.7 / 5

Summary

Pacific geoduck clams (Panopea generosa) are the world’s largest species of burrowing clam and are found along the Pacific Coast of North America from Alaska to California. The two wild-caught fisheries for geoduck are primarily in Washington State and British Columbia. The market for geoduck has primarily been based in Asia, but rise in popularity of sushi in North America has spurred a rise in domestic demand.

Geoduck are harvested with hand-held water jets (stingers), which liquefy the sand directly around the geoduck into a kind of quicksand for a few minutes, during which time the harvesters are able to easily retrieve the clam. These fisheries are not overfished nor are they experiencing overfishing. There is some moderate uncertainty around the data availability for the stock status in BC, whereas the Washington stocks are considered to be healthy. Due to the targeted nature of the harvest, there is no bycatch associated with this fishery.

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  • Stinger
Ocean Wise Recommended

Ocean Wise

Variety

Hard clam

Mercenaria mercenaria

Method

Wild

Hand harvest, Hand rake

Location

Massachusetts, North Carolina, Rhode Island

Overall Rating

3.3 / 5

Summary

Hard clams represent a valuable fishery. Landings have been decreasing since the 1950’s and experienced an accelerated decline in the 2000’s. Factors such as fishing restrictions, reduced prices, and depletions due to the recreational fishery are thought to be responsible for this decline.

No stock assessments are performed for hard clams so the stuck status and fishing mortality is unknown. More scientific data is needed for a more thorough understanding of the population, but existing management has been effective. Size limits, gear restrictions, and protected spawning areas are among the measures taken to protect the stock. The hand harvest of clams consists of either using a hand rake, hoe, or shovel. This method can be damaging to the habitat if wave action is not sufficient to redistribute the sediment after harvest. However, minimal amounts of bycatch are caught as hand harvesting is a highly selective fishing method. Hand harvest methods are associated with minimal amounts of bycatch as the gear is highly selective. In the event that non-target species are caught, they can be released unharmed and live.

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Ocean Wise Recommended

Ocean Wise

Variety

Clams, (Manila, Razor & Venus Clams, Cockles, Littlenecks, Steamers, Hard Clams)

Anadara spp., Cyclina spp., Merceneria spp., Meretrix spp., Sinonvacula spp., Tapes spp., Venerupis spp.

Method

Farmed

Dredge, Hand harvest, Hand rake

Location

Worldwide

Overall Rating

8.4 / 10

Summary

Clams have become an increasingly popular seafood item, and aquaculture of clams now surpasses wild sources of clams. Global clam production has increased in the past 26 years.

Clams are filter feeders that acquire nutrients from the seawater, relying on plankton as their primary feed source. Since no feed is given to the clams as they obtain nutrients from plankton in the water, there is no fouling of the water. The aquaculture of clams has few negative impacts on the ecosystem. The successful culture of clams usually depends on the health of the habitat. Therefore there is strong incentive to implement management measures that maintain a healthy habitat. Chemicals and medication are rarely used.

Although clams are usually farmed in valuable ecosystem areas, the process usually causes minimal damage to the environment. Clams are harvested by hand, rake or dredge. While hand harvesting and rakes cause minimal habitat damage, dredges can have several negative effects on the habitat when harvesting wild clams. Dredges are not known to be significantly damaging when used to harvest farmed clams.

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Ocean Wise Recommended

Ocean Wise

Variety

Atlantic surf clam

Spisula solidissima

Method

Wild

Hydraulic dredge

Location

US Atlantic

Overall Rating

3.8 / 5

Summary

The majority of Atlantic surfclams are caught in New Jersey. Landings peaked in the early 1970’s before quickly reaching a historic low in 1979. Recent landings have been decreasing due to a more northwards expansion of the species range, and the fishery is becoming less profitable.

Atlantic surfclams are moderately resilient to fishing pressure, as they reach maturity quickly, and have a moderately long lifespan. The population status is currently moderately healthy because although biomass is above target and fishing pressure is sustainable, a few local populations have been depleted.

The stock is well-managed by the Mid-Atlantic Fisheries Management Council. Stock assessments are performed regularly, and regulations are set based on scientific advice.

Hydraulic clam dredges are highly selective with little bycatch occurring.

Hydraulic clam dredges are highly disturbing to the habitat. They cause the suspension of sediment in the water which increases turbidity, create a trench where the dredge has passed through, change the density and composition of the substrate, reduce the organism diversity in the substrate, and temporarily leave dislodged organisms vulnerable to predation.

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Ocean Wise Recommended

Ocean Wise

Variety

Hard clam

Mercenaria mercenaria

Method

Wild

Hand rake

Location

Atlantic Canada

Overall Rating

3.3 / 5

Summary

Hard clams (also called northern quahogs) are fished commercially in the Southern Gulf of St Lawrence. Although abundance is unknown, management regulates the fishery via minimum size limits and fishing seasons. Clams do not have life history characteristics that make them vulnerable to fishing pressure. Rakes are used to manually harvest the clams. The use of rakes causes minimal bycatch and low levels of habitat damage.

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Ocean Wise Recommended

Ocean Wise

Variety

Razor clam

Siliqua patula

Method

Wild

Hand harvest

Location

Alaska & British Columbia

Overall Rating

3.9 / 5

Summary

The majority of the commercial Pacific razor clam fishery in BC occurs on Haida Gwaii North Beach. Pacific razor clam populations in British Columbia are healthy and fishing levels are sustainable. In Alaska, the fishing mortality is unknown. The populations are well-managed. In BC, the maximum fishing level is set at 22% of the available clam abundance. The average catch is 245,150lbs per year. In Alaska, the maximum annual catch is set at 350,000-400,000lbs.Pacific razor clams are hand-harvested during low tide. Any bycatch can be returned alive to the habitat, and the hand harvest causes little to no damage to the beach habitat. Pacific razor clams are primarily used as bait in crab fisheries, but recently there has been an increasing interest in the clams as a food product.

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Ocean Wise Recommended

Ocean Wise

Variety

Softshell clam

Mya arenaria

Method

Wild

Hand rake

Location

Atlantic Canada

Overall Rating

3.3 / 5

Summary

Softshell clams are fished commercially in the Gulf, Maritimes, and Quebec regions. Although abundance is unknown, management regulates the fishery via minimum size limits and fishing seasons. Clams do not have life history characteristics that make them vulnerable to fishing pressure. Rakes are used to manually harvest the clams. The use of rakes causes minimal bycatch and low levels of habitat damage.

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Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Food Alliance Shellfish

Variety

Clams

Multiple Species

Method

Farmed

Various

Location

Worldwide

Eco-Certification

Food Alliance Shellfish

Summary

In 2012 Seafood Watch completed a comprehensive study of different eco-certification programs to determine if any would be equivalent to their sustainability standards. As a result of this study this aquaculture eco-certification were determined to be equivalent to an Ocean Wise recommendation. Learn more about our recommendation policy here.

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  • Various
Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Aquaculture Stewardship Council (ASC)

Variety

Clams

Multiple Species

Method

Farmed

Various

Location

Worldwide

Eco-Certification

Aquaculture Stewardship Council (ASC)

Summary

In 2012 Seafood Watch completed a comprehensive study of different eco-certification programs to determine if any would be equivalent to their sustainability standards. As a result of this study this aquaculture eco-certification were determined to be equivalent to an Ocean Wise recommendation. Learn more about our recommendation policy here.

 

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  • Various
Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Canadian Organic

Variety

Clams

Multiple Species

Method

Farmed

Various

Location

Canada

Eco-Certification

Canadian Organic

Summary

In 2012 Seafood Watch completed a comprehensive study of different eco-certification programs to determine if any would be equivalent to their sustainability standards. As a result of this study this aquaculture eco-certification were determined to be equivalent to an Ocean Wise recommendation. Learn more about our recommendation policy here.

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  • Various
Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Clams and cockle Fishery from Ria de Arousa

Variety

Short-necked clam

Ruditapes philippinarum

Method

Wild

Hand harvest

Location

Ria de Arousa - Spain

Eco-Certification

Marine Stewardship Council (MSC)
Clams and cockle Fishery from Ria de Arousa

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

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Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Clams and cockle Fishery from Ria de Arousa

Variety

Grooved carpet shell

Duditapes decussatus

Method

Wild

Hand harvest

Location

Ria de Arousa - Spain

Eco-Certification

Marine Stewardship Council (MSC)
Clams and cockle Fishery from Ria de Arousa

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

Learn more about harvest methods

Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - US Atlantic Surfclam and Ocean Quahog

Variety

Atlantic surf clam

Spisula solidissima, Arctica islandica

Method

Hydraulic dredge

Location

U.S. Atlantic off the U.S. Northeast

Eco-Certification

Marine Stewardship Council (MSC)
US Atlantic Surfclam and Ocean Quahog

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

Learn more about harvest methods

Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Clams and cockle Fishery from Ria de Arousa

Variety

Pullet carpet shell clam

Venerupis pullastra

Method

Wild

Hand harvest

Location

Ria de Arousa - Spain

Eco-Certification

Marine Stewardship Council (MSC)
Clams and cockle Fishery from Ria de Arousa

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

Learn more about harvest methods

Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Clams and cockle Fishery from Ria de Arousa

Variety

Cockle

Cerastoderma edule

Method

Wild

Hand harvest

Location

Ria de Arousa - Spain

Eco-Certification

Marine Stewardship Council (MSC)
Clams and cockle Fishery from Ria de Arousa

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

Learn more about harvest methods

Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Clearwater Seafoods Banquereau and Grandbanks Arctic surf clam

Variety

Arctic surf clam

Mactromeris polynyma

Method

Wild

Hydraulic dredge

Location

Banquereau Bank, Grand Banks

Eco-Certification

Marine Stewardship Council (MSC)
Clearwater Seafoods Banquereau and Grandbanks Arctic surf clam

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

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Ocean Wise Recommended

Ocean Wise

Eco-Certification:

Marine Stewardship Council (MSC) - Razor clam fishery from Ria de Pontevedra

Variety

Razor clam

Ensis arcuatus

Method

Wild

Diver

Location

Ria de Pontevedra - Spain

Eco-Certification

Marine Stewardship Council (MSC)
Razor clam fishery from Ria de Pontevedra

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

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Variety

Razor shell clam

Ensis directus

Method

Wild

Hydraulic dredge

Location

Netherlands

Eco-Certification

Marine Stewardship Council (MSC)
DFA Dutch North Sea ensis

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

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Variety

Short-necked clams

Paphia malabarica

Method

Wild

Diver, Hydraulic dredge

Location

Ashtamudi Estuary, Kerala, India

Eco-Certification

Marine Stewardship Council (MSC)
Ashtamudi Estuary Shor-Necked Clam Fishery

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

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Variety

Hard clam

Meretrix lyrata

Method

Wild

Hand harvest

Location

Ben Tre Province - Vietnam

Eco-Certification

Marine Stewardship Council (MSC)
Vietnam Ben Tre clam hand gathered

Summary

Ocean Wise recommends some Marine Stewardship Council (MSC) certified fisheries, but not all. Learn more about how the MSC certification was bench-marked to Ocean Wise.

Learn more about harvest methods