National Survey of Sea Lice (Lepeophtheirus salmonis Krøyer and Caligus elongatus Nordmann) on Fish Farms in Ireland – 2019

Abstract

Farmed stocks of Atlantic salmon in Ireland are inspected on 14 occasions throughout the year to monitor sea lice levels as part of a national programme. Sea lice are a naturally occurring parasite found on marine fish, including salmonids. They are small ecto-parasitic copepod crustaceans and there are approximately 559 species. The objectives of the National Sea Lice Monitoring Programme are:  To provide an objective measurement of infestation levels on farms.  To investigate the nature of infestations.  To provide management information to drive the implementation of control and management strategies.  To facilitate further development and refinement of this strategy. The sea lice control and management strategy has five principal components:  Separation of generations.  Annual fallowing of sites.  Early harvest of two-sea-winter fish.  Targeted treatment regimes, including synchronous treatments.  Agreed husbandry practices.