Open Cage Salmon Farms have a negative impact on the environment, tourism, local fishermen and wild salmon. Also Farmed Salmon are not as good for your health as wild fish.



Uneaten feed and fish faeces associated with salmon farms can smother the sea floor beneath the farms, generating bacteria that consume oxygen vital to shellfish and other bottom-dwelling sea creatures.
Chemicals used in aquaculture include medicinal treatments, anti-fungal agents, pesticides, anaesthetics and especially anti-parasitic treatments (e.g. sea lice treatments). Discharges can have unintended consequences for marine organisms and human health. Antibiotics in particular have created antibiotic resistant strains of bacteria. Pollutants damage wild species that live in the marine ecosystem.

SBB have asked the Department of Agriculture Fisheries and Food (DAFF) for details of chemicals used in Bantry Bay and Kenmare Bay. The reply from DAFF stated that this data was held by the operators – Marine Harvest. Marine Harvest will not release this data which makes us wonder what have they got to hide?


The proposed salmon farm will generate high levels of waste. The nutrients in this waste are equivalent to sewage produced by a town 10 times the size of Bantry. In the summer Bantry Bay can have very poor water circulation and the nutrient enrichment (eutrophication) increases the risk of algal blooms.


It is estimated that the marine leisure sector supports 14,500 jobs, [compared to the 250 employed by Marine Harvest nationally] but that there is considerable potential to increase this, which could be important throughout the County (East and West Cork in particular). Both the North and West Cork Strategic Plan and the Cork Area Strategic Plan emphasise the potential for development of marine leisure. Both the Glengarriff Local Area Plan and the Adrigole Local Area Plan emphasise the importance of marine tourism and the national importance of the landscape in the area.

Angling makes a huge contribution to the tourist industry. The contribution to the economy of one wild salmon caught by an angling tourist is estimated to be €423. However the overall trend, over and over again around the world, is that salmon farming seems to have a negative impact on wild salmon. The mortality from farming that we find is really large in many cases—more than 50 percent reductions every year. That is not sustainable for any populations.

Read more about the impact on tourism

Local Fishermen

The fish farm is in traditional fishing grounds for local fishermen. There are already large areas of mussel lines in Bantry Bay. The fishermen do not want to lose any more fishing areas.

Due to toxic algae shellfish areas are frequently closed – sometimes for months. The nutrients from the fish farm may make the situation even worse. Closures are published on the Marine Institute Website.

Wild Salmon

Open cage salmon farms can have a big impact on wild salmon. The main concerns relate to sea lice, diseases and escapees breeding with wild salmon.

Sea Lice
The salmon louse lives on the fish’s mucus, skin and blood. A salmon smolt with more than 10-15 salmon lice is so weakened that it is not likely to survive. Harm occurs at lower infestation rates. Bite injuries from lice on the fish give pathogens a better foothold and can cause disease in the fish. In addition to the bite injuries, low nonlethal infestations will induce stress responses in the fish. Fish under stress have problems with their salt balance, reduced immunity and are more at risk of infections.Before fish farming activities began winter was a bottleneck for the salmon louse due to the low number of hosts at that time. The explosive growth of salmonid farming changed this situation drastically. Today there are large quantities of salmonids in the sea all year round. This makes it possible to sustain a large population of salmon lice and high infestation pressure all year.

Disesases which affect farmed salmon include

Ameobic Gill disease
Heart disease
Bone deformities

Escaped farmed salmon can compete with wild fish and interbreed with local wild stocks of the same population .
Research shows that the genetic future of wild populations receiving intrusions of farmed salmon is likely to be one of lower genetic variability, lower fitness, and higher vulnerability to environmental change. Escaped farmed salmon make up a larger proportion of catches and spawning stocks in Norway than in other countries, but escaped farmed salmon also occur, in Scotland, Ireland, Iceland, eastern Canada, and the US. In the North Atlantic, 20-40% of the salmon caught during experimental fishing in the open ocean north of the Faroe Is- lands during the mid-1990s were of farmed origin.

Protected species.

A number of protected species will be affected by the proposed Salmon Farm . For example:

  • Seals so popular with tourists and locals alike, are scared away from fish farms and even culled (shot). Seals have abandoned Ballycrovanne Harbour which is near a Marine Harvest Salmon farm.
  • The rare Arctic Tern disappeared from Roancarrig Beg adjacent to an existing fish farm. The tern is found near the proposed site. Dolphins and porpoises frequent the Bay and may also be scared away.
  • Wild Salmon populations are likely to be reduced and so will the fresh water pearl mussel which depends upon salmon for part of its life cycle.
  • Sustainablity

    Salmon are piscivores and need to eat fish to bulk up fast and remain healthy. Fish feed contains fish oil and fish meal. To make 1 kg of fishmeal and 0.5 kg of fish oil you need 5 kg of fish. The production of fish oil and meal is polluting and energy intensive. Although some fish feed uses meal and oil produced from inedible parts of the fish discareded during processing a large amount comes from fish such as anchovies and sardines, caught specifically to make fish meal . This is unsustainable.

    Food Quality

    Farmed salmon is nutritionally less valuable than wild salmon as its flesh has an increased fat content but less of the beneficial fat omega 3. Pollutants such as PCBs and dioxins make their way into the ocean and are absorbed by marine life. The pollutants accumulate in fat and is concentrated in the fish oil used for the salmon feed. Scientists are trying to determine the extent of the contamination in salmon and what levels are safe for human consumption.

    One study found levels of dioxins, chlorinated pesticides, cancer-causing PCBs and other toxins up to ten times greater in farmed salmon than in wild Pacific salmon. Scientists from Cornell University have concluded that “…consumers should not eat farmed fish from Scotland, Norway and eastern Canada more than 3 times a year” (Lang SS (2005)

    Fish feed contains Artificial Antioxidants ,in particular ethoxyquin (EQ), which are required to prevent the fish meal and oil in the feed going rancid. The antioxidants are carried over to fish fillets.  In order to protect public health Maximum Residue Limits (MRLs) have been established for several food additives by risk assessment bodies. As yet, the EU has not set MRLs for the five synthetic antioxidants that are authorised for use in animal feeds including EQ. In the EU EQ is not permitted for an additive for human food.

    A Marine Harvest spokesperson is quoted in the Southern Star article: ‘The “Produced in Ireland” guarantee is also a significant contributor to the success of our sales across sophisticated European markets’. However, a ‘sophisticated’ public will not eat farmed salmon – many chefs and seafood lovers snub farmed salmon as inferior to wild salmon – but will look for a healthier, safer, sustainable alternative.

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    2 thoughts on “Impacts

    1. I only wish people could see what this type of farming does, and how much damage it will do to an already badly damaged Bantry Bay.

    2. A further note as regards siting. There was an article in the Norwegian newspaper Altaposten dated 19.07.2007 including an interview with John Fredriksen as he was on a fishing trip in the Alta river in Norway. Fredriksen, who has a major interest in the fish farming company Marine Harvest (his daughter Cecilie is sitting on the board of directors, see:, is quoted as saying: “Environmental changes will result in the aquaculture industry having to move northwards.The temperature increase will force this trend” – so why try to farm a cold water fish like salmon in the warm waters of Ireland?

      Also, cold-water salmon oil is rich in alpha- linolenic acid (ALA), eicosapentanoic (EPA) and docosahexanoic (DHA). These are all fatty acids that are essential for the functions of the human body. Early Arctic explorers noted that the Eskimos, despite their consumption of high-fat and high-cholesterol foods, had a very low incidence of heart disease because their diets were rich in omega-3 fatty acids. Fish are the primary source of omega-3 fatty acids, but not all fish are created equal: the healthiest fish, with the most omega-3 fatty acids, live in cold water. Added to that, substituting vegetable proteins for animal proteins in the farmed salmon diet to reduce overfishing will also result in lower levels of the highly valued omega-3 fatty acid content in the farmed product.

      Wouldn’t a more northerly location for farming salmon be more suitable? Aren’t there other fish that could more profitably (and with less stress to the fish) be farmed on the south west coast of Ireland??

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