n-3 Oil sources for use in aquaculture – alternatives to the unsustainable harvest of wild fish

Abstract

The present review examines renewable sources of oils with n-3 long-chain ( ≥ C20) PUFA (n-3 LC-PUFA) as alternatives to oil from wild-caught fish in aquafeeds. Due to the increased demand for and price of wild-caught marine sources of n-3 LC-PUFA-rich oil, their effective and sustainable replacement in aquafeeds is an industry priority, especially because dietary n-3 LC-PUFA from eating fish are known to have health benefits in human beings. The benefits and challenges involved in changing dietary oil in aquaculture are highlighted and four major potential sources of n-3 LC-PUFA for aquafeeds, other than fish oil, are compared. These sources of oil, which contain n-3 LC-PUFA, specifically EPA (20 : 5n-3) and DHA (22 : 6n-3) or precursors to these key essential fatty acids, are: (1) other marine sources of oil; (2) vegetable oils that contain biosynthetic precursors, such as stearidonic acid, which may be used by fish to produce n-3 LC-PUFA; (3) single-cell oil sources of n-3 LC-PUFA; (4) vegetable oils derived from oil-seed crops that have undergone genetic modification to contain n-3 LC-PUFA. The review focuses on Atlantic salmon (Salmo salar L.), because it is the main intensively cultured finfish species and it both uses and stores large amounts of oil, in particular n-3 LC-PUFA, in the flesh.

Feeding aquaculture in an era of finite resources

“…One additional concern about the use of seafood processing wastes is that contaminants in the oil (PCBs, dioxins) of seafood by-products have the potential to bioaccumulate in farmed fish (3). The need to monitor this highly variable source of feed can act as an investment disincentive to feed producers.…”

Comparative evaluation of starting traditional and fermented mixed fodders for juveniles of pacific salmon

“…Согласно литературным данным (Бахарева, 2005;Miller, 2007;Остроумова, 2012;Пономарев и др., 2013), лососи употребляют жир прежде всего как источник энергии. Рыбные жиры вносятся в корма в качестве источника полиненасыщенных жирных кислот, в частности семейства омега-3, таких как эйкозапентаеновая (ЭПК) и докоза-гексаеновая (ДГК) кислоты, которые используются для обеспечения здорового роста.…”

Ácidos Graxos Poli-insaturados Ômega-3: saúde cardiovascular e sustentabilidade ambiental

“…A proporção de n-3 PUFA na ração depende do perfil alimentar dos peixes, ou seja, se são herbívoros, onívoros ou carnívoros. Os peixes carnívoros, como o salmão, necessitam de ração com maior concentração de n-3 PUFA quando comparados aos herbívoros [23,27] , o que pressiona ainda mais as reservas naturais de pequenos peixes. Assim, a não ser que haja uma dissociação entre a exploração das reservas de peixes e a aquicultura, especialmente por meio do desenvolvimento de fontes alternativas que mantenham o valor para a saúde humana dos peixes produzidos pela aquicultura, provavelmente essa alternativa não será suficiente para manter o fornecimento sustentável para o consumo humano.…”

“…Uma possível solução seria a mudança na composição da ração com substituição do óleo de pequenos peixes por óleo de microalgas. Isso possibilitaria uma contaminação mínima, além das algas constituírem fonte primária de n-3 PUFA na cadeia alimentar marinha [26,27] , o que poderia contribuir para a conservação da biodiversidade e preservação das reservas de peixes selvagens.…”