Amoeba gill disease in Atlantic salmon : a review of literature

Abstract

Hydrogen peroxide in sea water, at the concentrations tested in this study, did not appear to clear lesions of amoebae and other cellular debris as effectively as fresh water, although alterations to normal morphology of lesion-associated amoebae were noted. H2O2 is recognized as having a narrow safety margin which is influenced markedly by temperature (Thomassen 1993; Bruno & Raynard 1994; Cameron 1994a; Crosbie et al. 2012). The present study noted little difference in the toxicity of the chosen in vivo concentration between the two temperatures tested; however, the overall morbidity of 6.5–7.1% (up to 7 days post-treatment) would be commercially unacceptable. It was unclear whether mortality post-treatment was a direct or synergistic result of H2O2 exposure. Fish size, fish condition, AGD severity, stress and osmoregulatory capacity may all have potentially impacted upon observed mortalities.