Shellfish are one type of invertebrate species (animals that do not have a backbone or spinal column) that has been successfully domesticated through aquaculture practice. Bivalve shellfish – meaning the animal has two shells like mussels, clams and oysters – are the predominant type of shellfish grown by Canadian aquaculture operators.

The licenced operator owns the stock that is raised, but leases an approved area from the province in which they operate. Shellfish farmers do not feed their stock. Shellfish are filter feeders that consume the nutrients they need that already exist in the water. The stock is regularly replenished, nurtured, protected from predators, monitored and harvested by the farmer when the product reaches market size.

In Canada, there are four main species of bivalve shellfish that are cultured commercially: mussels, oysters, clams and scallops. Shellfish are grown in Newfoundland and Labrador, Prince Edward Island, Nova Scotia, New Brunswick, Quebec and British Columbia. New species are being researched for their potential for wide-scale, commercial production – such as abalone, geoducks, quahogs and sea urchins – and are in the experimental stages of development.

In 2005, there was 38,300 tonnes of shellfish produced valued at $67 million.