Clams: Farmed

Manila clam, Razor clam, Blood cockle, Northern quahog, Short-necked clam, Hard clam

N/A

Several species are farmed throughout the world, with the majority of aquaculture in China, Malaysia, Thailand, Italy and Korea with some farmed clams in the United States and Canada. Manila clams and razor clams are produced in the greatest abundances, with spat collected initially from natural populations.

Formulated feed is not used in grow-out of clams, thus fishmeal and fish oil are not used. Additionally, the majority of clam spat collected from the wild in the US and Canada do not appear to pose a significant risk to wild clam stocks. Therefore, the use of marine resources ranks low for cultured clams.

Clams produced by aquaculture and consumed in the US are primarily grown domestically or imported from Canada. There is little information to suggest that escapes of cultured clams in either country have had a negative effect on the wild stocks. Thus, as with all other forms of bivalve culture the risk of wild stock detriment by escape of culture species ranks low.

There are few reports of disease outbreaks affecting wild clam populations, thus there is little evidence to suggest there is a major threat to wild clams stocks posed by the culture of clams. Clams are susceptible to disease organisms primarily in the early life stages.Natural recruitment is regulated by the ability of juvenile clams and clam spat to survive natural predators and stressors. Under hatchery conditions, spat and juveniles can be monitored closely and measures can be taken to aid in the survival of seed stock. The risk of disease transfer from cultured clams to wild clams thus ranks low.

The grow-out of clams is accomplished in the natural environment, thus there is a beneficial effect on water quality. There are few reports of disease outbreaks at clam grow-out sites, thus there is little need for antimicrobials; however, antimicrobials are sometimes used in hatcheries. If clams are dredged, harvesting presents a moderate risk of disturbing the habitat, and the activity results in temporary declines in biodiversity. However, harvesting of culture plots is less destructive than harvesting wild clams because harvest is restricted to relatively small plots. This contrasts with dredging of long expansive clam beds for spat collection or capture fishery harvests. Presently, the risk of pollution and habitat effects thus ranks low for hand-raked harvest of cultured clams, while it ranks of moderate concern for clams harvested by dredging.

In the US, the Pacific Coast Shellfish Growers Association (PCSGA)has developed Best Management Practices (BMPs)for shellfish production on the west coast. The East Coast Shellfish Growers Association (ECSGA) submitted a pre-proposal to the Northeast Regional Aquaculture Center at the US Department of Agriculture (USDA) for funding the development of shellfish BMPs but has yet to get funding approved. BMPs also have been developed for the state of Massachusetts. The US EPA regulates the use of non-pharmaceutical chemicals used in shellfish culture and again laws are strict and shellfish producers typically do not use unapproved chemicals. In Canada, the British Columbia Shellfish Growers Association also is participating in the development of BMPs for production of shellfish.

Are these clams farmed or wild?

Adults and children can safely eat more than 4 meals per month + Low contaminant levels

No.