Sea lice control II: evaluation of a photomechanical device as an alternate sea lice control strategy

摘要

Sea lice (Lepeophtheirus salmonis) mobile stages were caught using a light trap in cages holding Atlantic salmon (Salmo salar) in Maine, USA, in 1997. The abundance of the sea lice was determined through calculation. Seasonal changes were shown withan increase in abundance as the temperature increased toward the end of the season. Analysis of manual lice-count data indicated variations in lice abundance between cages with and without deployed light traps. Analysis indicated that these variations were in larval presence (P=0.006) and presence of gravid females (P=0.015), but not in abundance of in pre-adults (P=0.172). Cage net condition also affected the abundance and infection intensity of sea lice on Atlantic salmon within aquaculture cages. Abundance of larvae were affected by net condition (P=0.01), as were abundance of pre-adults on salmon (P=0.04). The infection intensity of gravid females, however, did not vary with net condition (P=0.74). Other species of zooplankton, such as American lobster (Homarus americanus) larvae and various Brachipod larvae, were also collected with the light trap. It is concluded that the light trap could provide an alternate method of lice control in aquaculture cages.