More info about Fish-Farm in the Höga Kusten World Heritage?
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A Balanced Opinion About Fish Farms?
I am a Biologist and a businessman. My wife is a Biologist and a Biology Teacher. We both try to be reasoned in our opinions, yet there is little that can be said that is positive about fish farms. Most discussions and scientific papers will focus on risk and damage control or the ecological impact. This is not surprising, since the intention is to produce healthy fish by an unnatural, high density rearing method. The very act of putting fish into a high population density increases the risk of generating disease, infestation and infection in both the caged fish and the local “natural” population.
Without making this text into a small book I will attempt to headline the issues of which I am aware and, in my opinion, should be considered when agreeing to the introduction of Fish Farms into a local ecology. What is important is not just that dangers exist, but that people agree the risk is worth taking. It should also be shown that the authorities giving approval have reviewed every risk, that a full risk assessment was undertaken by qualified ecologists and that the report of the assessment was made public.
Risk to indigenous wild fish
1. Sea Lice. Migrating fish risk acquiring the infective larval sea lice parasite as they pass through the areas around the cages.
2. Contamination. Transfer of infectious disease from farm fish. e.g. Infectious Salmonid Anaemia (ISA) or Infectious Pancreatic Necrosis (IPN)
3. Genetic Dilution (reduced fitness) resulting from escaped farm fish breeding with wild naturals. Currently this is of major concern in Scotland.
4. Pheromone Barrier. It is theorised that a chemical messenger can be released by caged fish which creates a “fear” marker that will frighten migrating fish from returning to their breeding streams or rivers.
Risk to other wild life.
1. Sound Repellents. To reduce the damage caused to containment nets by Seals one method is to use acoustic barriers. While this may work, it also drives away other large species from a much bigger area. Whales, Dolphin and Porpoise are all thought to be affected.
2. Chemical and Medicine Controls. Used to control or reduce disease or infestation these agents can have a harmful effect on a significant range of living organisms. Those affected can be simple single cell algae to Lobster, Crayfish or Molluscs. There is a European Directive that the fish farm must obey and the Swedish environment agency must enforce. This directive, “The Dangerous Substances Directive – 76/464/EEC” stipulates the limits of concentration of chemicals (specifically medicines) that are used by fish farms. This directive was not made without good reason.
It is very important to realise the Ullangers Fjord has almost no tidal pull. Therefore the “washing effect” of a normal tide will not occur. This could lead to the significant build-up of toxin or waste. Should this happen it would be difficult to correct.
Damage to the Sea Bed
The sea floor can be changed in numerous ways by the presence of Fish Farms. Not just directly below the cage, but in zones moving away from the area. These changes can be in the normal balance of nutrient elements (food) or natural elements (e.g. organic Nitrogen)
The significant amount of waste materials – faeces or debris – creates a sewer effect. However the actual volume of the ocean is expected to dilute this.
Rationale for Fish Farms
There is already evidence that this method of food production has poor profit margins. The economy of scale (size and number) could drive a limited development toward a much bigger one as production costs increase.
There already exist questions about the economic production of fish food to service fish farms and the components used to make up this food. How would people feel if genetically modified materials where to enter the ingredients of the fish food?
General Policy
Managed properly there is every reason to believe many of the problems above may never occur. But why take the risk in the first place? Surely not the creation of 20 or 30 jobs? The question must be asked “Is this a general shift in the attitude to responsible management of the local ecology?”
A last thought.
Incidentally, one of the reasons my wife and I have just bought a house in the High Coast is because of the outstanding beauty of the area and the World Heritage status. I am surprised this prestigious accolade would appear to mean so little to those in authority. The ecology of the area should not be so easily put at risk.
Roger Osborne
26th. September 2006