Estimating costs of sea lice control strategy in Norway

• Three types of treatments were used and three treatment strategies were also determined.
• Treatments were very costly and costs were very sensitive to treatment types used and timing of treatments conducted.
• Strategically treating fish at the early state was more economic than at later stage.
• Bath treatment had higher costs than wrasse and in-feed treatments.
• Wrasse is a better option economically and ecologically, but cannot generate instantaneous reduction in sea lice level.

This paper explores the costs of sea lice control strategies associated with salmon aquaculture at a farm level in Norway. Diseases can cause reduction in growth, low feed efficiency and market prices, increasing mortality rates, and expenditures on prevention and treatment measures. Aquaculture farms suffer the most direct and immediate economic losses from diseases. The goal of a control strategy is to minimize the total disease costs, including biological losses, and treatment costs while to maximize overall profit. Prevention and control strategies are required to eliminate or minimize the disease, while cost-effective disease control strategies at the fish farm level are designed to reduce the losses, and to enhance productivity and profitability. Thus, the goal can be achieved by integrating models of fish growth, sea lice dynamics and economic factors. A production function is first constructed to incorporate the effects of sea lice on production at a farm level, followed by a detailed cost analysis of several prevention and treatment strategies associated with sea lice in Norway. The results reveal that treatments are costly and treatment costs are very sensitive to treatment types used and timing of the treatment conducted. Applying treatment at an early growth stage is more economical than at a later stage.