Saltwater Fish Farming

Canadian Aquaculture




General Aquaculture
Salmon Farming
Shellfish Farming

General Aquaculture

Why do we need aquaculture?

The output of the world’s wild fisheries is either steady or declining, yet the human population continues to grow. Aquaculture already supplies half the world’s seafood consumed by humans. The United Nations Food and Agriculture Organization forecasts a global seafood shortage of 50 – 80 million tonnes by 2030, and aquaculture will help meet that growing demand.

Which species are grown in Canada?

The main species grown in Canada are salmon, mussels, oysters and trout. Canada also produces steelhead, arctic char, Atlantic cod, sablefish, geoducks, Atlantic halibut, quahogs, white sturgeon, tilapia and scallops.

How much does aquaculture contribute to the Canadian economy?

Our aquaculture industry generated $969 million in direct sales in 2006, and well over $1 billion in indirect value to the rural Canadian economy. Salmon accounts for approximately 80 percent of the industry’s value.

How is aquaculture regulated in Canada?

The Canadian aquaculture industry is governed by a framework of 73 pieces of federal and provincial legislation. The location and day-to-day operations of all Canadian aquaculture facilities are regulated by six federal agencies: Fisheries and Oceans Canada, Environment Canada, Canadian Food Inspection Agency, Canadian Environmental Assessment Agency, Transport Canada, and Health Canada.

Where does aquaculture take place in Canada?

Aquaculture takes place in every Canadian province, plus the Yukon. British Columbia and New Brunswick are the top two provincial producers, while Newfoundland and Labrador ranks third.

How are predators controlled by aquaculture companies?

Most predators, which may include seals, birds of prey and raccoons, are protected by federal or provincial law. The most common control methods are barriers – such as nets, covers or building enclosures – auditory deterrents and removal. Firearms are used only as a last resort.

What kind of feed is given to farmed fish?

Different types of feeds, mainly distinguished by variations in pellet size, fat and protein content, are used according to the life stage of the fish. Many ingredients are the same as those used in the production of feed for domestic animals, and are all natural products, including oilseed meals, grain products, protein-rich meals of animal origin (fish, poultry), fish and plant oils.  Farmed shellfish rely on natural food in the water for their growth, and are not given additional food.

What is feed conversion ratio?

Feed conversion ratio (FCR) is calculated from the number of kilograms of feed used to produce one kilogram of fish. Feeding farmed fish is more efficient than feeding land-based animals, and the average FCR for farmed fish is close to 1:1.

What are pigments?

In nature, fish such as salmon get their pink colour from eating crustaceans.. Carotenoids, the most common naturally occurring pigments, are given to farmed fish to provide Vitamin A, function as antioxidants, and enhance the animals’ immune system. Carotenoids also give farmed fish, such as salmon and Arctic Char, their pink colour.

Where does fish feed come from?

According to the Food and Agriculture Organization of the United Nations, about 90 percent of global fishmeal production is from oily fish species such as anchovies, mackerel, pilchard, capelin and menhaden. These small, bony fish are generally unsuitable for human consumption. As an alternative to fishmeals, the aquaculture industry is increasingly using vegetable proteins and oils.

Are fish oils associated with dioxins and PCBs?

A Canadian Food Inspection Agency study found that dioxin, furan and PCB levels in fish oil samples do not exceed the Canadian Guidelines for Chemical Contaminants and Toxins in Fish and Fish Products. Dioxins and Furans are measured in parts-per-trillion, while PCBs are measured in parts-per-billion.  Levels in farmed fish are well below most wild fish and daily foodstuffs eaten by Canadians.

Are diseases spread from farmed to wild fish?

There is no evidence to indicate that disease outbreaks at salmon farms have resulted in any increase in diseases in wild salmon. Research indicates that farmed salmon are at a higher risk of contracting a disease from wild fish. The aquaculture industry is strictly regulated and has developed disease vaccines, alternative treatments and good production practices to further reduce the incidence and severity of disease impacts.

Are antibiotics used in fish farming?

The use of antibiotics in aquaculture is much lower than in land-based animal farming, and a strictly regulated withdrawal period ensures the active compounds are gone before the fish are sold to consumers. The Canadian Food Inspection Agency (CFIA) is responsible for monitoring food safety and conducts spot audits on farmed fish for the presence of drug residues. Antibiotics can only be used when prescribed by a veterinarian.

Q&A – Salmon Farming

Which species of salmon are farmed?

  • Atlantic salmon
  • Pacific salmon
  • Coho salmon (also called silver salmon)
  • Chinook salmon (also known as spring or king salmon)
  • Rainbow trout
  • Arctic Char
  • Brook trout

How much of Canada’s aquaculture industry is comprised of salmon farming?

Salmon is Canada’s most important farmed species, accounting for approximately 80 percent of the industry’s value.

Is farmed salmon safe?

Yes. All salmon – wild and farmed – is considered a healthy food choice with proven health benefits. According to the US Department of Agriculture, farmed Atlantic salmon has higher levels of omega-3 fatty acids than any of the five species of wild Pacific salmon. The Canadian Food Inspection Agency tests farmed salmon for contaminants, pesticides and dioxins.

Is farmed salmon a healthy nutritional choice?

Both farmed and wild salmon are high in vitamins A and D and carotenoids, which are thought to help prevent cancer. Salmon is low in saturated fat, and contains 20 percent more protein than hamburger, steak and pork loin. Salmon is also an excellent source of omega-3 and omega-6 fatty acids.

How is salmon farming regulated?

The Canadian aquaculture industry is governed by a framework of 73 pieces of federal and provincial legislation, making it one of the most strictly regulated industries in the world. Both the location and day-to-day operations of all Canadian aquaculture facilities are regulated by six federal agencies: Fisheries and Oceans Canada, Environment Canada, Canadian Food Inspection Agency, Canadian Environmental Assessment Agency, Transport Canada, and Health Canada.

Do salmon farms affect the sea floor beneath farm sites?

Aquaculture has the lightest environmental effects of any form of large-scale food production. These effects are limited largely to the ocean floor in the immediate vicinity of salmon farms, are short-term, and fully reversible. Salmon waste and uneaten food on the ocean floor can cause temporary oxygen reduction and other chemical changes as they decompose. For this reason, salmon farms are situated in deep waters over sand and silt sea bottoms with low fauna diversity. Some of the organisms that live in these soft sediments in fact thrive under salmon farms because the wastes are a source of food for them.

Are farmed salmon different from the wild salmon?

Farmed and wild salmon have the same ancestors, and are genetically very similar. Salmon farmers select fish that have demonstrated good performance in terms of health, flesh quality and growth, and use these fish as broodstock.

Do salmon escape from farms?

Escapes have been dramatically reduced since the early 1990s, and have been estimated at well below one percent in every year since 1995. A farmed salmon that escapes into the wild is poorly adapted for survival, and only small proportions of escaped salmon survive. A small number of farmed salmon interbreeding with a wild population has little impact because only small amounts of new genetic material is being added, and natural selection continues to play a role.

What feed is given to farmed salmon?

Strict raw material criteria are used to ensure a high quality feed. All of the ingredients used in both moist and dry aquaculture feed are approved for use by the Canadian Food Inspection Agency. Much of the protein used in fish feed comes from small, bony fish – such as anchovies and mackerel – which are unsuitable for human consumption. Other sources of protein include soybean meal, corn gluten meal, canola meal and wheat gluten and poultry by-products. Essential vitamins, minerals and carotenoids – which provide salmon with vitamin A and give salmon their pink colour – are added to the diet. All feed ingredients are of natural origin and of the highest quality.

Why are sea lice mentioned in relation to salmon aquaculture?              

Sea lice are naturally occurring marine crustacean (related to shrimp and crab) parasites that affect both wild and farmed fish of all types. Sea lice management is an important issue for both salmon farmers as well as the wild fishery. Although no direct cause and effect relationship between sea lice, salmon farms and wild salmon has been identified, salmon farms are monitored to ensure early detection. Sea lice treatments involve the use of approved therapeutants, such as SLICE. On average, less than five percent of farmed salmon feed contains therapeutants, and a mandatory withdrawal period ensures none is present in the final product sold to consumers.

Q&A – Shellfish Farming

What species of shellfish are farmed?

Mussels, oysters, clams and scallops are the most common species in Canadian aquaculture. We are investigating the farming of other species such as abalone, geoducks, quahogs and sea urchins

What type of health and nutritional benefits are associated with shellfish consumption?

Shellfish are healthy sources of protein, rich in vitamins and minerals, and low in fat. They are also a good source of omega-3 fatty acids.

Why are oysters and mussels the most commonly farmed species?

Oysters and mussels are in high demand and have high survival rates. Both wild and hatchery reared seed for these species are readily available.

How are farmed and wild shellfish different?

Farmed and wild shellfish have the same ancestors. There is very little difference between wild and cultured shellfish, as shellfish seed were originally harvested – and are still harvested – from the wild. On the west coast, the species of oyster that is the basis of both the wild and farmed oyster industries is an introduced species from Japan that was brought to the West Coast around 1913. The native oyster of the northwest coast is now rarely found. Both wild and farmed shellfishare filter feeders that consume phytoplankton already in the ocean.

What are the stages of shellfish farming?

There are five stages:

Seed – The farming process begins with the collection of seed stock from existing wild stocks or from hatchery sources.

Nursery – Nursery rearing of shellfish begins once the seeds have set and lasts until the juvenile shellfish are ready to be transferred to the grow-out site. Nursery rearing systems are intertidal, suspended in deep water, or built on land or floating rafts with seawater flow-through.

Growout – Once seeds are at the right size, they are removed from the nursery sites, and put into socks, tubes, trays, lantern nets, or set on long lines, in bags, on tables, on the sea floor or the beach.

Grading and Sorting – To ensure the highest survival and growth rates, it is essential to periodically sort and grade the stock into appropriate sizes. This must be done for oysters, clams or scallops especially during the juvenile stages.

Harvest – It takes anywhere from 1½ to four years for shellfish to reach harvest size. Harvesting techniques range from hand harvesting to crew-operated harvest machines, and each species of shellfish requires different farming techniques.

What are the different ways to grow shellfish?

Just as there are many species of shellfish, there are many types of shellfish culture: Tray, tube, bag and cage, raft, longline and intertidal.

Where are the shellfish farms located?

In Canada, shellfish farms are located primarily in remote areas or coastal communities in British Columbia, Newfoundland and Labrador, New Brunswick, Prince Edward Island, Nova Scotia and Québec.

Is fouling a problem on shellfish growout sites?

Yes. Shellfish farmers combat fouling by control, avoidance and prevention. Fouling organisms include barnacles, tunicates, tube worms, bryozoans, hydroids (a small branching organism related to jellyfish and sea anemones) and encrusting sponge. Fouling is avoided by using a fresh water or saline solution, pressure washing, timing production cycles, maintaining high growth rates and exposure to air.



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