Wild salmonids and sea louse infestations on the west coast of Scotland: sources of infection and implications for the management of marine salmon farms†

摘要: The sea louse (Lepeophtheirus salmonis Kroyer) is a major health problem for both farmed and wild salmonids. This paper investigates epidemiology management in the salmonfarming zone of western Scotland. Based on review marine ecology salmon (Salmo salar L) trout trutta L), catch farm production statistics, best estimates were made numbers hosts present coastal waters March-June 2000. Applying data ovigerous female infections fecundity, sources risks larval transmission to modelled. Farm second spring primary host group (98% fish), while salmonids (<1%) escaped (2%) relatively insignificant. produced 97% eggs at high levels (eight lice per 78% low (one fish). Wild <1% under scenarios, but 3% 21%, respectively. All potentially cross-infect one another, are more likely infect smolts, also other salmon. Monitoring June 1998-2000 by Association West Coast Fisheries Trusts corroborated model's conclusions. Localised epizootics occurred every year coincided with presence local farms. In areas mixed-year class farms, evident spring, single-year production. least 14-40% infected lethal infestations lice. Ovigerous <0.005 fish required 2000 produce less than those emitted With industry's continued expansion, thus increased salmon, target zero will be farms minimise impacts Due limited long-term efficacy availability medicines, strategies discussed which improve control, including over large areas, alternate S1-S1/2 smolt inputs, 11-month cycles.