Identifying salmon lice transmission characteristics between Faroese salmon farms

Abstract

Sea lice infestations are an increasing challenge in the ever-growing salmon aquaculture sector and cause large economic losses. The high salmon production in a small area creates a perfect habitat for parasites. Knowledge of how salmon lice planktonic larvae disperse and spread infection between farms is of vital importance in developing treatment management plans to combat salmon lice infestations. Using a particle-tracking model forced by tidal currents, we show that Faroese aquaculture farms form a complex network. In some cases as many as 10% of the infectious salmon lice released at one farm site enter a neighboring fjord containing another farm site. Farms were characterized as emitters, receivers or isolated, and we could identify 2 clusters of farms that were largely isolated from each other. These farm characteristics are a valuable input for the development of management plans for the entire Faroese salmon industry.