Production, mortality, and infectivity of planktonic larval sea lice, Lepeophtheirus salmonis (Kroyer, 1837): current knowledge and implications for epidemiological modelling

Current sea louse models attempt to estimate louse burdens on wild and cultured salmon by predicting the production and distribution of lice larvae and estimating the risk of transmission. While physical characteristics of water bodies and weather can be accurately modelled, many aspects of sea lice biology require further parameterization. The aims of this review are (i) to describe current knowledge regarding the production, mortality, and infectivity of planktonic sea lice larvae and (ii) to identify gaps in knowledge and suggest research approaches to filling them. Several major gaps are identified, and those likely to have the greatest impact on infection levels are (i) egg production, viability and hatching success, (ii) predation in plankton and (iii) copepodid infectivity profiles. A key problem identified in current parameter estimates is that they originate from a number of sources and have been determined using a variety of experimental approaches. This is a barrier to the provision of best or consensus estimates for use in modelling. Additional and more consistent data collection and experimentation will help to fill these gaps. Furthermore, coordinated international efforts are required to generate a more complete picture of sea louse infections across all regions experiencing problems with sea lice.