Assessing sea lice management strategies for the Norwegian salmon industry
Summary
Norwegian salmon farming has experienced rapid growth in the last few decades, and has turned into a billion-dollar industry. The Norwegian government aims to support further growth with the goal to quintuple value creation from aquaculture by 2050. Before this goal can be achieved, however, several challenges that hamper growth need to be overcome. The growing sea lice pressure is commonly perceived as the single most important challenge. Sea lice are parasites affecting salmon by feeding on its skin and blood and the economic impact they have on the industry is massive. The impact of lice is predominantly a consequence of the high density of salmon kept on farms, which allows the lice to accumulate and multiply more easily.
The Norwegian government has been regulating the growth of the salmon industry by utilizing a Maximum Allowable Biomass system and a Traffic Light System, which is specifically designed to reduce sea lice levels. The functioning of these systems is heavily debated. The industry itself also responded to the sea lice challenge by implementing different strategies to control sea lice levels but so far these have not yet proved to provide long-term solutions. Furthermore, methods that are currently used, come with numerous concerns related to fish welfare and environmental sustainability.
This study aims to assess the sea lice management strategies and associated delousing methods and cage technologies that are currently used and explored to reduce the sea lice pressure while taking into account multiple indicators. Multi-Criteria-Mapping was used to let stakeholders appraise the most common delousing methods. This is a mixed-method, software-assisted tool that allows participants to assign scores to several options, delousing methods in this case, for a number of self-defined criteria.
A total of seven participants scored the initial list of eight options and three of them proposed an additional option. It became clear that every method has its flaws and that there is no one-size-fits-all solution. It is location-dependent whether a certain method or cage technology works best, for which criteria need to be developed. The sea lice problem calls for a novel approach, in which prevention is chosen over cure. Innovative technologies like depth-based interventions, land-based farming and genetic editing might provide better long-term preventative solutions. Next to that, big data is believed to have enormous potential for managing farms in general. To support these solutions, proper coordination by the Norwegian government is pivotal.