Decontaminated fishmeal and fish oil from the Baltic Sea are promising feed sources for Arctic char (Salvelinus alpinus L.)—studies of flesh lipid quality and metabolic profile

Abstract

The Baltic Sea is one of the world's most pollution‐threatened brackish environments and limited direct consumption of fatty fish from the Baltic Sea is recommended. The use of decontaminated Baltic Sea fish raw materials as fish feed could be a strategy to recycle Baltic Sea nutrients back into food chain, while relieving pressure on aqua‐feed in the growing aquaculture industry. In this study, defatted fishmeal and semi‐purified fish oil from the Baltic Sea were used in fish feeds for Arctic char (Salvelinus alpinus L.). The effects of the Baltic Sea‐sourced fish feeds on flesh lipid quality and fish metabolomics, compared with a standard commercial feed as a control, were determined. 1H NMR‐based metabolomics studies indicated disturbances in energy metabolism and hepatic toxicity in fish fed both crude fishmeal and crude fish oil, associated with up‐regulation (IGF‐I, GHR‐I, PPARα, PPARβ1A) and down‐regulation (SREBP‐1 and FAS) of hepatic genes expression. The content of n‐3 long chain polyunsaturated fatty acids was not affected by the decontamination process. Thus, this short‐term study demonstrates that decontaminating Baltic Sea‐sourced fishmeal and fish oil reduces adverse effects in Arctic char.Practical applications: Decontaminated fish materials from the Baltic Sea were shown to be promising feed ingredients for Arctic char (Salvelinus alpinus L.) compared with untreated Baltic Sea‐sourced fish feed, which induced changes in fish physiology associated with energy metabolism and hepatotoxicity. Baltic Sea‐sourced fish materials containing high levels of long chain polyunsaturated fatty acids are valuable feed ingredients.The Baltic Sea‐sourced fishmeal (CFM and DFM) and fish oil (CFO and SPFO) were tested in fish feeds for Arctic charr (Salvelinus alpinus), compared with a commercial diet as a control. Flesh lipid quality, metabolic profile in liver and muscle and hepatic gene expression (IGF‐I, GHR‐I, SREBP‐1, etc.) were evaluated.