Salmon Farming Problems and the Need for Change

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Improving Public Awareness

Watershed Watch produced two films to increase public awareness of the problems associated with open net cage salmon farming and the need to improve the sustainability of the industry. Wild Salmon in Trouble provides an overview of how sea lice from salmon farms affect wild salmon. In the film Aquacultural Revolution, many prominent scientists and First Nation representatives speak their minds about the salmon farming industry and the numerous problems associated with it.

Aquaculture Threats

As currently practiced, salmon fish farming is a major threat to wild salmon, the world over. To help get the message across, Watershed Watch conducts education and outreach programs in an effort to raise awareness of harmful industry practices, as well as producing and sponsoring peer reviewed research to add to the science on this issue. We have also taken progressive steps to work directly with industry in an attempt to conduct collaborative research to come to agreed conclusions on the impacts of salmon farming. Unfortunately, industry and government still deny much of the peer-reviewed, published science that highlights the negative impacts of salmon farming. Watershed Watch is a founding member of the Coastal Alliance for Aquaculture Reform, and has also represented aboriginal groups such as the Musgamagw Tsawataineuk Tribal Council and the Ehattesaht Tribe in examinations of salmon farm impacts in their traditional territories.

Some of the ways open net pen salmon farming threatens wild salmon include:

Sea lice

Sea lice are small ocean parasites that feed on the skin of fish. Lice normally do not harm adult salmon; however, small numbers of lice may kill juvenile salmon. Scientists agree that the pink salmon collapse in the Broughton Archipelago in 2002 is likely related to sea lice from salmon farms. From an expected 3.6 million salmon, only 147,000 spawning fish returned.

Watershed Watch Executive Director's peer-reviewed paper estimated that 1.6 billion lice eggs were produced over a 2-week period by Broughton Archipelago salmon farms in the winter of 2004. Although sea lice are a natural part of marine ecosystems, sea lice coming from salmon farms are not and they resultantly cause severe problems for wild salmon.

What is the connection between sea lice and salmon farming?

Although sea lice occur naturally in the Northern Hemisphere, louse infestations have only recently put wild salmon populations at risk because of salmon farming. Stocking hundreds of thousands of fish in small pens makes fish farms ideal breeding grounds for lice, and drastically increases the number of lice in surrounding waters.

Fish farms are typically located in sheltered bays and inlets near rivers usually on or near the migratory routes juvenile salmon use to reach the open ocean. Salmon farms create an unnatural reservoir of sea lice that is especially detrimental to juvenile salmon heading for the ocean simply because of their small size. One or two sea lice may be enough to kill a juvenile salmon. Much higher numbers have been observed recently on juvenile pink salmon near BCs salmon farms.

Are sea lice a problem elsewhere?

The problems associated with sea lice from salmon farms are not limited to British Columbia. Major infestations of sea lice, both on wild and farmed salmon, have been reported everywhere salmon farms have been established. Salmon farmers monitor and treat farmed salmon for sea lice with pesticides that lower lice levels; however, even very low numbers of lice per farmed salmon can add up to billions of sea lice eggs being released into surrounding waters. There are also concerns and evidence that sea lice may become resistant to the current treatment of choice, a chemical called Slice, that is added to the fish feed.

The Weight of Evidence

An abundance of peer-reviewed and published science shows that:

For more information see the following Watershed Watch reports on aquaculture:

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The threat of disease transfer between wild and farmed salmon is serious. Both Bacterial Kidney Disease (BKD) and Infectious Hematopoietic Necrosis (IHN) are common throughout the salmon farming industry. BKD is a leading cause of death to farmed Chinook and coho, and a serious danger to wild pink, sockeye, and chum salmon. IHN, a virus carried by adult wild salmon without visible symptoms, is particularly dangerous both to juvenile wild sockeye and to farmed Atlantic salmon which have little natural resistance. As long as open-net pens allow constant exchange of water to the marine environment, diseases and parasites will also likely be exchanged between farmed and wild salmon.

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Escaped Farmed Salmon

Do you know there are almost no commercial fisheries for wild Atlantic salmon left because of their dwindling numbers in the wild? So if you're buying Atlantic salmon, chances are it was farmed salmon. Farmed Atlantic salmon frequently escape and have been seen in more than 80 rivers in British Columbia and are known to have spawned in the Tsitika River on northern Vancouver Island. This is a concern because escaped farmed salmon are capable of competing with wild salmon for food and habitat. For more information see Dr. John Volpe's report Super un-Natural.

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Effects on Surrounding Marine Ecosystems

Many different compounds and chemicals are used in industrial salmon farming operations. In an effort to keep farmed fish healthy, salmon farmers add drugs such as antibiotics and therapeutants to the salmon feed as needed. The chemical Slice is used to treat farmed salmon for sea lice infestations, but it may also affect non-target wild crustaceans such as crabs and may remain in the environment. Other chemicals such as antifoulants and disinfectants are also released into the environment by farms in an attempt to control unwanted organisms and diseases. Little is known about how these chemicals affect the marine ecosystems.

Farm salmon are held in flow through nets and cages which allow fish waste and excess feed to freely pass into marine waters. These wastes frequently accumulate under salmon farms and may degrade the habitat surrounding the farm.

One solution that may minimize the problems associated with open-net cage salmon farming is closed containment technology which provides a barrier between farmed salmon and the marine ecosystem.

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