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Identifying 'firebreaks' to fragment dispersal networks of a marine parasite

Version 2 2024-05-30, 11:36
Version 1 2019-01-23, 17:24
journal contribution
posted on 2024-05-30, 11:36 authored by Francisca Samsing, Ingrid Johnsen, Eric TremlEric Treml, Tim DempsterTim Dempster
Marine ecosystems are beset by disease outbreaks, and efficient strategies to control dispersal of pathogens are scarce. We tested whether introducing no-farming areas or 'firebreaks' could disconnect dispersal networks of a parasitic disease affecting the world's largest marine fish farming industry (∼1000 farms). Larval salmon lice (Lepeophtheirus salmonis) are released from and transported among salmon farms by ocean currents, creating inter-farm networks of louse dispersal. We used a state-of-the-art biophysical model to predict louse movement along the Norwegian coastline and network analysis to identify firebreaks to dispersal. At least one firebreak that fragmented the network into two large unconnected groups of farms was identified for all seasons. During spring, when wild salmon migrate out into the ocean, and louse levels per fish at farms must be minimised, two effective firebreaks were created by removing 13 and 21 farms (1.3% and 2.2% of all farms in the system) at ∼61°N and 67°N, respectively. We have demonstrated that dispersal models coupled with network analysis can identify no-farming zones that fragment dispersal networks. Reduced dispersal pathways should lower infection pressure at farms, slow the evolution of resistance to parasite control measures, and alleviate infection pressure on wild salmon populations.

History

Journal

International journal for parasitology

Volume

49

Pagination

277-286

Location

Amsterdam, The Netherlands

ISSN

0020-7519

eISSN

1879-0135

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2019, Australian Society for Parasitology

Issue

3-4

Publisher

Elsevier