Low concentrations of sodium hypochlorite affect population dynamics in Gyrodactylus salaris (Malmberg, 1957): practical guidelines for the treatment of the Atlantic salmon, Salmo salar L. parasite. Issue 12 (15th January 2014)

• Record Type: Journal Article
• Authors: Hagen, A G; Hytterød, S; Olstad, K
• Is Part Of: Journal of fish diseases. Volume 37:Issue 12(2014:Dec.)
• Page Start: 1003
• Page End: 1011
• Publication Date: 2014-01-15
• Subjects: Fishes -- Diseases -- Periodicals; 639.3
• DOI: 10.1111/jfd.12218
• Languages: English
• ISSNs: 0140-7775

Abstract

<abstract abstract-type="main" id="jfd12218-abs-0001"> <title>Abstract</title> <p>Atlantic salmon, <italic>Salmo salar </italic>L. parr (age 1+), infected by the monogenean ectoparasite <italic>Gyrodactylus salaris</italic> (Malmberg, 1957), were exposed to chlorine (Cl)‐enriched water at three different concentrations: Cl<sub>low</sub> (0–5 μg Cl L<sup>−1</sup>), Cl<sub>medium</sub> (18 μg Cl L<sup>−1</sup>) and Cl<sub>high</sub> (50 μg Cl L<sup>−1</sup>). There was a negative correlation between <italic>G. salaris</italic> infections and the hypochlorite concentrations added. The parasite infection was eliminated by day 6–8 and day 2–4 in the groups Cl<sub>medium</sub> and Cl<sub>high</sub>, respectively, while inhibition of <italic>G. salaris</italic> population growth was observed in the Cl<sub>low</sub> group. An important note to this matter, however, is that the <italic>G. salaris</italic> specimens observed at day 6 in Cl<sub>medium</sub> and at day 2 in Cl<sub>high</sub> were all considered dead by subjective judgement. No mortality in the salmon parr was observed during the first 8 days of the experiment, demonstrating that Cl has a stronger effect on <italic>G. salaris</italic> than on the salmonid host. The differences in sensitivity between the parasite and the Atlantic salmon indicate that hypochlorite has a potential use as a parasiticide with a therapeutic margin. The low‐dose sensitivity may imply that Cl pollution in urban areas may pose a greater risk towards biodiversity than previously assumed.</p> </abstract>