Escapes: slipping the net
Norwegian regulators are concerned at the number of farmed fish that could be mixing with wild populations.
Fish farm escapes are becoming a far too frequent occurrence, the Norwegian government and industry authorities believe.
Last year, according to the Directorate of Fisheries, more than 93,256 salmon got out of various facilities – and that figure doesn’t include incidents at trout and cod farms.
Not since the black year of 2019, when the total was three times last year’s figure, has the number been so high.
The situation is looking no better this year with 27,000 fully mature salmon bursting out of a Mowi facility during a winter storm in February. Admittedly, the weather played a huge part in what could later turn out to be a very expensive incident.
So, less than two months into 2025 the figure is more than a quarter of last year’s total.
Even allowing for the size of Norway’s aquaculture industry, neighbouring salmon farming countries, such as Iceland, Scotland and the Faroe Islands, do not seem to have quite the same problem.
So is it hubris, carelessness or simply lack of concern? Hardly: fish escape for many reasons with storms, technical issues, vessel propellers damaging the nets and poor maintenance and equipment among them. Sometimes it can be simply down to bad luck.
The Directorate says its figures are uncertain because it is the companies themselves who are responsible for reporting estimates of how many have got free.
It also says that every year escaped fish appear that cannot be linked to an officially reported incident, but are discovered through reports from the public.
“There is therefore reason to believe that the number of incidents is somewhat higher than what is being reported,” it adds.
‘Zero vision’
Norway’s fish farmers insist they have a clear zero vision for salmon escapes, but they are still a very long way from getting close to that target.
They also say the operational goal is to reach a level where escaped salmon do not negatively affect wild fish.
This means that the number of escapes and the extent of individual cases should be reduced to a minimum.
This is an important goal for both the industry and the management. A number of measures, supported by considerable resources, have been taken to achieve this target.
Sporting groups are quick to blame salmon companies for the very serious decline in wild salmon numbers in many parts of Norway though they conveniently ignore the fact that numbers are down in areas where there is no salmon farming.
However, there is no doubting that escapes can and do pose a threat to wild salmon.
It is not that the industry is standing idly by as several measures at great cost are in place to try to get close to the zero target goal.
Measures include the introduction of new traps to protect wild salmon after experts warned they could become endangered as a result of contact with their farmed counterparts.
The Norwegian Climate and Environment Ministry has pledged 15m NOK to install river traps in the country’s northernmost region of Finnmark, as well as to enclosing all coastal fish farms by 2030.
Also artificial intelligence systems that will help to prevent salmon escaping from farms in even the roughest sea conditions are currently being developed by SINTEF, in collaboration with the research centre SFI Exposed. The project is using deep learning to develop and improve systems that can identify irregularities in salmon cage nets. This is done by feeding a digital neural network with images showing the building blocks of an intact net. These images enable the programme to react when it observes something out of the ordinary, such as a hole.
Frequent inspections of sea cage nets are being increased, along with greater use of alerts when very bad weather is expected.
Meanwhile, the Norwegian government recently gave notice that it intends to introduce stricter technical requirements for the escape-proof design and operation of fish farms.
The industry says avoiding a possible negative effect on native wild fish populations in salmon rivers through escaped salmon spawning together with wild salmon is the most important reason why so many resources have been invested in preventing escapes over the past 10-15 years.
The public information organisation laksefakta.no says it is also the reason why escape prevention, including regular inspections, must be a daily focus of all operations at the fish farms.
It points out that every salmon that escapes is a major economic loss for the industry, and affects the industry’s reputation and framework conditions.
The Aquaculture Operation Regulations require that those responsible for the fish farming facilities must have the necessary knowledge to prevent, detect and limit the escape of fish.
It continues: “An updated emergency plan must be available at all times, which must also include an overview of how escapes can be detected, limited and the recapture of escaped fish made more efficient.
“There is also a requirement that a risk assessment be carried out with the aim of minimising the risk of escapes. This must also form the basis for systematic measures. The mesh size in the net bag must be adapted to the size of the fish so that it cannot escape, and nets must be checked both before and regularly during operation.
“In 2013, a technical standard for land-based aquaculture facilities for fish was also published, with requirements for risk analysis, design, construction, operation, etc.”
The regulations define figures and thresholds for when the level of escaped salmon in a river is so high that measures must be implemented or considered to be implemented. And it is the board of OURO, the aquaculture industry’s association tasked with reducing escape numbers, that will make these assessments and plan measures.
Participation in the association is mandatory, replacing an older voluntary scheme.
Laksefakta argues that other important measures to prevent escapes should include:
- Training and exchange of experience. Courses in escape prevention have been conducted every year since 2008. Both industry players, the administration and researchers contribute.
- There is a high demand and participation in these courses.
- Innovation and improvement of equipment.
- Ensuring that mooring and equipment are adapted to the conditions at the sea location, and that different items of equipment at the facility are well adapted to each other.
- Preparation of best practice guides.
It maintains there will be a need for increased research efforts in the future to clarify to what extent, and at what levels, escaped salmon affect wild salmon.
All activity will have an impact, but it will be important to know whether and, if so, to what extent the survival and ability of salmon to develop in the wild is actually changed or affected by escaped salmon.
The industry vision of zero escapes is probably too much to expect, given the uncertainties around rough weather and human error.
But 93,000 on the run is far too high, suggesting a lot more care and attention is required.
For more salmon news see Sector Focus at www.fishfarmermagazine.com/salmon
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