THE ECONOMIC VALUE OF CLEANERFISH

Sealice is considered one of the main environmental issues challenging the sustainability of salmon farming. Regulations to limit this externality have led farmers to apply several different treatments, including mechanical, chemical and pharmaceutical treatments as well as preventative measures such as fallowing and using cleanerfish (Fig. 1). Some of the treatments may negatively affect salmon production, such as mechanical sealice removal and chemical treatment. Thus, preventative alternatives, such as cleanerfish, are increasingly used to control the sealice stock within the farm location and keep it from reaching the regulatory threshold. This paper investigates the economic value of cleanerfish by estimating the likelihood of avoiding the sealice regulation threshold.

Specifically, using an ordered logistic regression, the probability of being over the sealice limit within a month is estimated, conditional on the number of cleanerfish and other control variables. In addition, the loss in biomass related to the farms being over the limit provides a measure of revenue forgone. Results indicate the use of cleanerfish reduces the need for other palliative treatments by 4%. Moreover, salmon biomass lower when the location is over the sealice limit. This suggests farmers incur monetary losses not only related to the necessary treatments, but also in revenue forgone by the decreased biomass.

The estimates suggest a reduction of 7-20% in biomass. Thus, for a location with a standing biomass of 1261 t per month and using around 2000 cleanerfish, the value of cleanerfish in order to reduce palliative treatments and the biomass loss related to that is around 2 NOK/kg of salmon.