Estimation of spatiotemporal transmission dynamics and analysis of management scenarios for sea lice of farmed and wild salmon

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 77; no. 1; pp. 55 - 68
• Main Authors: Peacock, Stephanie J, Krkošek, Martin, Bateman, Andrew W, Lewis, Mark A
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 2020; Canadian Science Publishing NRC Research Press
• Subjects: Analysis; Aquaculture; Aquaculture industry; Archipelagoes; Crustaceans; Disease transmission; Dynamics; Ectoparasites; Epidemics; Estimates; Farms; Fish culture; Fish migration; Infectious diseases; Infestation; Juveniles; Lepeophtheirus salmonis; Lepeoptheirus; Lice; Management; Mariculture; Marine; Migrations; Mortality; Natural populations; Oncorhynchus gorbuscha; Oncorhynchus keta; Outbreaks; Parameters; Parasites; Parasitism; Pest outbreaks; Restocking; Salmo salar; Salmon; Salmon culture; Salmoniformes; Seafood industry; Spatial variations; Studies; Surveys; Sustainability; Temporal variations; Time series; Wildlife; Canada; United Kingdom; British Columbia; INE, Canada, British Columbia, Broughton Archipelago
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/cjfas-2019-0036

Parasite transmission between farmed and wild salmon affects the sustainability of salmon aquaculture in Pacific Canada. Understanding and managing parasites in aquaculture is challenged by spatial and temporal variation in transmission dynamics. We developed a mechanistic model that connects sea louse (Lepeoptheirus salmonis) outbreak and control on farmed salmon (Salmo salar) to spatiotemporal dynamics of sea lice on migrating wild juvenile salmon (Oncorhynchus keta and Oncorhynchus gorbuscha). We fitted the model to time series of sea lice on farmed salmon and spatial surveys of juvenile wild salmon in the Broughton Archipelago. We used the parameterized model to evaluate alternative management scenarios based on the resulting sea louse infestations and predicted mortality of wild salmon. Early and coordinated management of sea lice on salmon farms was most effective for controlling outbreaks in wild salmon, while uncoordinated treatments led to a resurgence of sea lice on salmon farms during the juvenile salmon migration. This study highlights the importance of incorporating spatiotemporal variability when considering infectious disease dynamics shared by farmed and wild hosts, particularly when migratory wildlife are involved.