Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study

Salmon louse (Lepeophtheirus salmonis) infestations pose a significant challenge to the salmonid farming industry. While most conventional water-treatment protocols primarily target lice at parasitic stages once attached to the fish, preventive measures targeting planktonic/free-living stages are sc...

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Main Authors: Elia Ciani, Marit Stormoen, Stein Ivar Antonsen, Frank Nilsen, Even Hjalmar Jørgensen, Anna Zofia Komisarczuk
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:Aquaculture Reports
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Online Access:http://www.sciencedirect.com/science/article/pii/S2352513425002807
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author Elia Ciani
Marit Stormoen
Stein Ivar Antonsen
Frank Nilsen
Even Hjalmar Jørgensen
Anna Zofia Komisarczuk
author_facet Elia Ciani
Marit Stormoen
Stein Ivar Antonsen
Frank Nilsen
Even Hjalmar Jørgensen
Anna Zofia Komisarczuk
author_sort Elia Ciani
collection DOAJ
description Salmon louse (Lepeophtheirus salmonis) infestations pose a significant challenge to the salmonid farming industry. While most conventional water-treatment protocols primarily target lice at parasitic stages once attached to the fish, preventive measures targeting planktonic/free-living stages are scarce. This study investigated the effects of fine calcium oxide (CaO) particles on salmon louse planktonic stages under controlled laboratory conditions. The study tested a range of concentrations (0.2 g/L to 0.6 g/L) exposure times (2–15 minutes) and frequency of exposures (from daily to every five days). The results indicated that the effects of CaO exposure were positively correlated with the concentration, duration, and frequency of the treatment. Exposure to CaO (10 minutes at 0.2 g/L) reduced by 60–70 % the number of nauplii reaching the copepodid stage by decreasing survivability and molting. CaO treatment (10 min at 0.6 g/L) induced up to 90 % mortality of free-living copepodids. In infection trials using copepodids that survived CaO treatment, there was a 42.1 % reduction in the number of parasitic chalimus, pre-adult, and adults on the salmon five weeks post-infection as compared to control. The LC50 for copepodids ranged between 0.54- and 0.36-g/L for an exposure time of 2–10 minutes, respectively. This laboratory study serves as an essential first step in validating the efficacy of CaO and establishes a foundation for future field trials to assess its potential as an antiparasitic treatment in aquaculture.
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spelling doaj-art-ab191c4027df4f3585b3bf9ffd72ab632025-08-20T02:57:17ZengElsevierAquaculture Reports2352-51342025-09-014310289410.1016/j.aqrep.2025.102894Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory studyElia Ciani0Marit Stormoen1Stein Ivar Antonsen2Frank Nilsen3Even Hjalmar Jørgensen4Anna Zofia Komisarczuk5Department of Production Animal clinical Sciences, Norwegian University of Life Sciences, Ås, Norway; Aquaculture Unit, Edmund Mach Foundation, San Michele all’Adige, Italy; Corresponding author at: Department of Production Animal clinical Sciences, Norwegian University of Life Sciences, Ås, NorwayDepartment of Production Animal clinical Sciences, Norwegian University of Life Sciences, Ås, NorwaySeacalx AS, Gratangen, NorwayDepartment of Biological Sciences, SLCR-Sea Lice Research Centre, University of Bergen, NorwayDepartment of Arctic and Marine Biology, The Arctic University of Norway, Tromsø, NorwayCenter for Molecular Medicine Norway, University of Oslo, NorwaySalmon louse (Lepeophtheirus salmonis) infestations pose a significant challenge to the salmonid farming industry. While most conventional water-treatment protocols primarily target lice at parasitic stages once attached to the fish, preventive measures targeting planktonic/free-living stages are scarce. This study investigated the effects of fine calcium oxide (CaO) particles on salmon louse planktonic stages under controlled laboratory conditions. The study tested a range of concentrations (0.2 g/L to 0.6 g/L) exposure times (2–15 minutes) and frequency of exposures (from daily to every five days). The results indicated that the effects of CaO exposure were positively correlated with the concentration, duration, and frequency of the treatment. Exposure to CaO (10 minutes at 0.2 g/L) reduced by 60–70 % the number of nauplii reaching the copepodid stage by decreasing survivability and molting. CaO treatment (10 min at 0.6 g/L) induced up to 90 % mortality of free-living copepodids. In infection trials using copepodids that survived CaO treatment, there was a 42.1 % reduction in the number of parasitic chalimus, pre-adult, and adults on the salmon five weeks post-infection as compared to control. The LC50 for copepodids ranged between 0.54- and 0.36-g/L for an exposure time of 2–10 minutes, respectively. This laboratory study serves as an essential first step in validating the efficacy of CaO and establishes a foundation for future field trials to assess its potential as an antiparasitic treatment in aquaculture.http://www.sciencedirect.com/science/article/pii/S2352513425002807Lepeophtheirus salmonisSalmon louseCalcium oxideAtlantic salmon
spellingShingle Elia Ciani
Marit Stormoen
Stein Ivar Antonsen
Frank Nilsen
Even Hjalmar Jørgensen
Anna Zofia Komisarczuk
Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
Aquaculture Reports
Lepeophtheirus salmonis
Salmon louse
Calcium oxide
Atlantic salmon
title Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
title_full Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
title_fullStr Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
title_full_unstemmed Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
title_short Optimization of calcium oxide treatment against salmon louse (Lepeophtheirus salmonis). A controlled laboratory study
title_sort optimization of calcium oxide treatment against salmon louse lepeophtheirus salmonis a controlled laboratory study
topic Lepeophtheirus salmonis
Salmon louse
Calcium oxide
Atlantic salmon
url http://www.sciencedirect.com/science/article/pii/S2352513425002807
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