Aquaculture: Farming the ocean — Where science and nature meet

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From egg to plate, Atlantic salmon farmers are striving to grow their fish as naturally as possible and base their farming practices on science and research.

Peter Darnell has been farming native Blue Mussels in Mahone Bay since 1982 and his operation exemplifies the very definition of responsible aquaculture. Peter has learned over the years that to be successful as a shellfish farmer you must have clean water and you cannot exceed the carrying capacity of your leases. — Photo courtesy of the Aquaculture Association of Nova Scotia

(Originally published in the January 2012 issue of the Nova Scotia Business Journal - Aquaculture feature)

Here’s a fact about salmon farming that most people don’t know: salmon occupy less than four per cent of the space in their net pen, so they have plenty of room to mimic natural schooling patterns.

From egg to plate, Atlantic salmon farmers grow their fish as naturally as possible and base their farming practices on science and research.

“We don’t leave our farming decisions to chance,” says Pamela Parker, executive director of the Atlantic Canada Fish Farmers Association.

The science-based approach begins before a farmer even receives a permit to establish a farm. Salmon farm sites are carefully chosen where water currents naturally provide the best conditions for fish well-being and environmental sustainability. Each potential new site undergoes a detailed, site-specific environmental review and assessment under the federal Canadian Environmental Assessment Act, Navigable Waters Protection Act, and Fisheries Act, plus the provincial Aquaculture Act and the Clean Environment Act.

These reviews scrutinize everything from the farm’s potential impact on water quality, fish habitat, wild fish and shellfish populations, marine mammal and other wildlife populations, and the area’s biodiversity. This process also examines potential impacts on human health, recreational and commercial fisheries, navigation, tourism, cultural or historical heritage or current use by First Nations.

Farmed salmon grown in Atlantic Canada originate from Saint John River wild salmon. They begin their life cycle as eggs, which are collected from adult salmon broodstock and placed in temperature-controlled tanks in a freshwater hatchery.

After about one year, the salmon are moved to saltwater farm sites where they continue to grow for another 18 to 24 months in large net pens that float on the ocean. The pens rise and fall with the tide and are cleansed by the rushing tide water.

Farmed salmon eat nutrient-dense, dry pellets made mainly from small, bony fish, such as anchovies, which are unsuitable for human consumption. Essential vitamins, minerals and carotenoids, which provide salmon with vitamin A and give salmon their pink colour, are added to their diet. No dyes or growth hormones are used.

Farmers use underwater video cameras, sensors and sophisticated feed technology to monitor feed delivery to avoid overfeeding and manage waste.

“Farmers adhere to environmental policies and codes of practice developed with government, researchers and the community,” says Parker. “Those practices include routinely fallowing between crops, conducting regular maintenance, inspecting  net pens, and monitoring water conditions.”

The day-to-day operations of all Canadian aquaculture facilities are regulated by six federal agencies. Provincially, the majority of regulations are administered through aquaculture and fisheries departments and departments of environment.

Farmers conduct regular government-audited sediment testing of the ocean floor to ensure farms meet high environmental standards with results publicly available. Regulators also conduct site-specific reviews of each farm during each year of production.

“The ocean floor underneath our net pens is actually a vibrant ecosystem alive with a range of sea creatures favoured by the lobster so important to our wild fishery,” says Parker. “We’ve shown over the past 30 years we can grow salmon in their natural environment with minimal risk to wild stocks like lobster and to the marine environment. Our farm practices ensure that our industry remains sustainable — environmentally, socially and economically — for generations to come.”


Aquaculture fast facts:

• In Nova Scotia, 750 people are employed in aquaculture, generating a value of $58 million (2010 statistics).

• In 2009, finfish production alone in Nova Scotia was valued at $47.6 million and employed 271 people, including both full-time and part-time workers.

• Cooke Aquaculture Ltd.’s salmon farming expansion will add 417 new direct full-time jobs, over 795 indirect full-time jobs and a payroll of $38 million — essentially doubling the economic impact of the current aquaculture industry in Nova Scotia over the next two years.

• Atlantic Canada produces over 30 per cent of Canada’s farmed salmon.

Source: Atlantic Canada Fish Farmers Association


Sea farmer spotlight: Peter Darnell, Indian Point Marine Farms Ltd.

Peter Darnell has been farming native Blue Mussels in the beautiful waters of Mahone Bay since 1982 and his operation exemplifies the very definition of responsible aquaculture. Peter has learned over the years that to be successful as a shellfish farmer you must have clean water and you cannot exceed the carrying capacity of your leases.

Shellfish are natural filter feeders and extract their feed from the ocean without any additional food provided by the farmer. As a result, the carrying capacity of a given shellfish farm is entirely determined by the natural availability of food in the ocean.

Extensive environmental monitoring by the provincial Department of Fisheries and Aquaculture has indicated that Peter’s farms have in no way negatively impacted the environment in and around his leases even after 29 years of continuous use.

Courtesy of the Aquaculture Association of Nova Scotia

Organizations: Nova Scotia Business Journal, Cooke Aquaculture, Department of Fisheries and Aquaculture

Geographic location: Atlantic Canada, Nova Scotia, Saint John River Mahone Bay

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Recent comments

  • Dennis Reid
    January 10, 2012 - 22:26

    1. On feed, it is not right to take fish out of third world mouths and use them to make fish for first world mouths. And the supplies are dropping so much that some feed companies are taking the krill supplies from the Antarctica because bait fish supplies are dwindling. 2. The science on fish farming is ten feet high saying farms should be on land. 3. Farmed fish are grown in dense conditions and aggression and disease issues result from this. ISA, for instance has been carried around the world by fish farms after it was developed in Norway in 1984. Now an equally dangerous disease of densely packed fish HSMI is being spread from Europe. 4. There are many videos on Youtube of the ocean below farms and they show sewage. Also, the water column is infected for many miles. This needs to be cleaned. 5. There have been a lot of lobster found dead on the east coast, and the use of cypermethrin has found Cooke Aquaculture charged with using illegal lice chemicals. 6. There is lots of research out there that says farmed fish have organic chemical pollution. Just Google it. And you will find a number of seafood lists that say to avoid buying farmed salmon. 7. The feed and monitoring equipment is one reason why employment in fish farms is so low and drops once it is installed. 8. Fish farms like to claim they are under the most stringent laws in the country they are in. This is currently maintained in Canada, Norway, Scotland and Chile. As every country has different laws, this cannot be true. 9. Sustainable aquaculture is an oxymoron. And one of these days the USA is going to put countervailing duties on Canadian farmed fish because the damage to wild stocks will be seen as a subsidy. .