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Safety in Exposed Aquaculture Operations Strategies and methods for reducing risk


Norway is the largest producer and exporter of farmed Atlantic salmon and rainbow trout worldwide. The national ripple effects are significant. New concepts are being developed and tested for fish farming in exposed locations offshore, but still the dominant fish farm technology is floating net cages in coastal areas. Hence, Norwegian fish farming face sustainability and reputational challenges due to farmed salmon escape and salmon lice. Fish farm operations are characterised by five risk dimensions: Risk to material assets, personnel, fish welfare and health, environment, and food safety.
The main objective of the PhD project is to develop knowledge and methods for improved management of safety in exposed sea-based fish farming. Fish escape has been used as the study case. The following summarises the contributions:
• A new categorisation system for fish escape event data has been developed. The registered fish escape events are reanalysed and re-categorised into i) hazardous event, ii) direct causes, iii) underlying factors, iv) coupling factors. Four main groups of hazardous events are established: Fish escape due to 1) submerged net, 2) holes in the net, 3) loss of fish, 4) structural damage without damage to the net. The fish escape data is reanalysed using the new categorisation system according to the consequence of the event (size of escape). The most frequent hazardous event is "holes in the net" and are most often caused by net chafing by equipment/structures or operational failures. Fish escape scenarios are drawn based on the reanalysis of the Fdir database with the hazardous event as the top event, direct causes at second level and contributing causes at third level. Coupling factors are illustrated as the fourth level of the scenarios. By including all events, the most frequent hazards and causes are captured regardless of consequence.
• The term "human error" is explored and specified in the context of recent fish escape accidents experienced by informants participating in an interview study. Nine organisational and human factors which influence fish escape accidents are identified. The operations associated with increased risk for fish escape are i) net and sinker tube/weight system handling, ii) delousing operations, iii) vessel-assisted operations. These operations are also associated with elevated occupational risk levels. The findings document a need for increased attention to organisational safety indicators in fish farm operations.
• There is currently no systematic evaluation of operational safety in terms of organisational conditions in the fish farming industry. The OSC method, originally developed for assessment of operational safety levels in the oil and gas industry, has been adapted and evaluated for use in the aquaculture industry. The seven organisational factors from the original OSC are relevant also for fish farm operations: Work practice, competence, procedures and documentation, communication, workload and physical environment, management, change management.
• The aquaculture industry must comply with regulatory requirements for risk assessments of fish escape, technical condition of fish farms, vessel design and operation, environmental risk, occupational risk, fish welfare and health, and food safety. The current practices differ significantly from the recommended risk assessment procedure on several points. To close the gaps, a new approach which satisfy the requirements is suggested. Risk assessments should be based on the operations carried out at the fish farm. This will provide an overview of the hazards associated with the work tasks and factors influencing the risk levels. The fish farming companies are recommended to develop risk assessment templates for the yearly updates to be adapted to each vessel or fish farm, and to ensure involvement of the workers.


Doctoral dissertation


  • Research Council of Norway (RCN) / 237790





  • Norwegian University of Science and Technology
  • SINTEF Ocean / Fisheries and New Biomarine Industry




Norges Teknisk-Naturvitenskapelige Universitet





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