Salt as a decontamination agent to control bacterial load in Artemia salina cultures

Abstract Live food represents one of the major sources of bacterial contamination in larval culture. Since Artemia are widely used as live food, this approach has been thoroughly studied. Several techniques using antibiotics, ozone, chemical compounds, algae, and probiotics, have been tested to reduce bacterial load in Artemia . This research looked at the potential of salt to reduce bacterial contamination. Two salt treatments, consisting of 1 — a dip in a 200 g L − 1 salt solution, and 2 — a 24 h enrichment in a 60 g L − 1 salt solution, were compared to a commercial antimicrobial enrichment product (A1 DHA Selco), a mix of commercial antibacterial products and a non-antimicrobial enrichment product (AlgaMac) as well as a control (enriched with AlgaMac). All treatments induced a reduction of the bacterial count of over 99.999983%. It was expected that different enrichment products would induce variations in the nutrient profiles, but the levels of DHA were higher in the Artemia treated with either of the salt treatments, when compared to the control. The salt treatment did not affect EPA and ARA levels, neither did it affect the levels of vitamins C and E. Therefore, salt allows for a comparable or higher reduction of the bacterial load in Artemia nauplii, than that obtained with other techniques, with a limited effect on nutrient profiles. Even more, the use of salt does not limit the choice of the enrichment product used, since it can be used in combination with a non-antibacterial enrichment product. Statement of relevance Utilization of salt allows for a comparable or higher reduction of the bacterial load in Artemia nauplii than the ones obtained with more complicated or less durable techniques such as antibiotics, formaldehyde and ozone. As demonstrated in the present study, commercial enrichment products exist that allow for an achievement of similar results, but the use of salt does not limit the choice to enrichment products containing antimicrobial compounds, and produces minimal variations in the nutritional profiles of the Artemia. Therefore this new technique could be useful for all fish culture using Artemia.