10 - Application of biological control: use of cleaner fish

Abstract

Cleaner fish (wrasse and lumpfish) are now used as a biological control for sea lice on commercially farmed salmon in Europe and Canada. The use of cleaner fish is an environmental and efficient alternative for removal of sea lice. In order to remove lice efficiently, the cleaner fish need to be healthy and the welfare of the cleaner fish is of major importance. Farmed cleaner fish are preferred due to better disease control through vaccination and screening programs. Strict regulations for harvesting wild-caught wrasse are needed to ensure their long-term vitality. In this chapter, the current knowledge of cleaner fish management, applications, and challenges, including brood stock, hatchery, transport, and deployment, in net pens has been summarized. Furthermore, this chapter gives an overview of diseases, antibacterial treatment and vaccination, and what is known about nutrition requirement and health status. Finally, parameters useful for monitoring the health status of the cleaner fish and ethical considerations are discussed.