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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #336082

Research Project: Genetic Improvement Of Marine Fish and Shellfish

Location: National Cold Water Marine Aquaculture Center

Title: Scratching the surface: A sentinel exploration of sea louse infestations in Cobscook Bay, Maine

item FREDERICK, CATHERINE - University Of Maine
item Pietrak, Michael
item BARKER, SARAH - University Of Maine
item BRICKNELL, IAN - University Of Maine

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2017
Publication Date: 1/12/2017
Citation: Frederick, C., Pietrak, M.R., Barker, S., Bricknell, I. 2017. Scratching the surface: A sentinel exploration of sea louse infestations in Cobscook Bay, Maine. Northeast Aquaculture Conference and Exposition Meeting Abstract. p. 39-40.

Interpretive Summary:

Technical Abstract: Cobscook Bay is a tidally energetic system (tidal range ~5.7 m and tidal velocities >2 m s-1) comprised of cool waters (annual mean of 10') capable of supporting marine aquaculture. The bay has three active Atlantic salmon Salmo salar farms in close proximity to Passamaquoddy Bay and New Brunswick, Canada. A high volume of tidal exchange also passes through the narrow channels of Cobscook Bay and produces a unique hydrodynamic environment. This research focuses on establishing sea louse infection trends and explores local mechanisms of transport and infestation to better define sources of infectious pressure. It is hypothesized that the degree of water connectivity between regions and unique properties of sampled sites nurtures infestation. Sentinel cages were strategically placed in Cobscook Bay between June 2013 and June 2015. A total of 272 juvenile Atlantic salmon were deployed for seven days once a month to capture viable infectious pressure. All sites had a prevalence of 70% or greater by May, reaching 100% in late summer, which was maintained through fall of sampled years. The earliest and highest rates of nfestation were observed at Pembroke Landing (p < 0.05; Kruskal-Wallis Test), furthest from active farm sites. Temperature and salinity data were similar between sampled sites, but current velocities were significantly different. The greater levels of infestation observed at Pembroke Landing may be associated with the site’ unique water current profile, providing insight for future modeling and pest management strategies.