Arsenic speciation and arsenic feed-to-fish transfer in Atlantic salmon fed marine low trophic feeds based blue mussel and kelp

• Published in: Journal of Trace Elements in Medicine and Biology
• Main Authors: Silva, Marta S., Tibon, Jojo, Sartipiyarahmadi, Sahar, Remø, Sofie C., Sele, Veronika, Søfteland, Liv, Sveier, Harald, Wiech, Martin, Philip, Antony J. Prabhu, Berntssen, Marc
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Element speciation; Heavy metals; HPLC-ICP-MS; Novel feed ingredients; Safe seafood; /dk/atira/pure/sustainabledevelopmentgoals/climate_action; name=SDG 13 - Climate Action; /dk/atira/pure/sustainabledevelopmentgoals/life_below_water; name=SDG 14 - Life Below Water; Atlantic salmon
• Online Access: https://orbit.dtu.dk/en/publications/098bdaed-e230-4ffd-92ba-2efb0feefacd; https://doi.org/10.1016/j.jtemb.2023.127319; https://backend.orbit.dtu.dk/ws/files/338844352/1-s2.0-S0946672X23001955-main.pdf

Background: Aquaculture aims to reduce the environmental and climate footprints of feed production. Consequently, low trophic marine (LTM) resources such as blue mussels and kelp are potential candidates to be used as ingredients in salmon feed. It is relevant to study potential undesirables associated with their use, as well as assessing food safety by investigating their transfer from feed-to-fish. The marine biota is well known to contain relatively high levels of arsenic (As), which may be present in different organic forms depending on marine biota type and trophic position. Thus, it is important to not only obtain data on the concentrations of As, but also on the As species present in the raw materials, feed and farmed salmon when being fed novel LTM feed resources. Methods: Atlantic salmon were fed experimental diets for 70 days. A total of nine diets were prepared: four diets containing up to 4 % fermented kelp, three diets containing up to 11 % blue mussel silage, and one diet containing 12 % blue mussel meal, in addition to a standard reference diet containing 25 % fish meal. Concentrations of As and As species in feeds, faeces, liver and fillet of Atlantic salmon were determined by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography coupled to ICP-MS (HPLC-ICP-MS), respectively. Results: The use of kelp or blue mussel-based feed ingredients increased the concentration of total As, but maximum level as defined in Directive 2002/32 EC and amendments was not exceeded. The concentrations found in the experimental feeds ranged from 3.4 mg kg −1 to 4.6 mg kg −1 ww. Arsenic speciation in the feed varied based on the ingredient, with arsenobetaine dominating in all feed samples (36–60 % of the total As), while arsenosugars (5.2–8.9 % of the total As) were abundant in kelp-included feed. The intestinal uptake of total As ranged from 67 % to 83 %, but retention in fillet only ranged from 2 % to 22 % and in liver from 0.3 % to 0.6 %, depending on the marine source ...