Insects reared on seaweed as novel feed ingredients for Atlantic salmon (Salmo salar) : Investigating the transfer of essential nutrients and undesirable substances along the seaweed-insect-fish food chain

• Main Author: Biancarosa, Irene
• Other Authors: orcid:0000-0003-0464-9248
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Bergen 2020
• Subjects: Atlantic salmon; Salmo salar
• Online Access: https://hdl.handle.net/11250/2761076

Traditionally, major sources of protein and lipid in aquaculture fish feeds have been fish meal and fish oil. However, fish stocks used for fish meal and fish oil production are fully exploited, therefore prices of these ingredients continue to increase. In recent years, substantial progress has been made by the research community and feed producers to test novel sources of protein and lipid to replace marine feed ingredients in aquaculture. Insects have been identified as feed ingredients of great potential for farmed fish. In particular, being high in energy and protein content, they seem a good source of ingredients in compound feeds for Atlantic salmon (Salmo salar). However, insects reared on terrestrial feedstuff are not a source of the essential marine omega-3 fatty acids, which Atlantic salmon has a dietary requirement for. The AquaFly project aimed to develop novel insect feed ingredients for Atlantic salmon, contributing essential nutrients to produce robust and healthy fish. To achieve this, tailoring of the nutrient composition of the insect feed ingredients towards fish nutrient requirements was investigated through the use of seaweed as feeding substrate for the insects. Seaweeds are known to contain marine omega-3 fatty acids and essential minerals (like iodine) which are generally absent in terrestrial feedstuff for insects. At the same time, seaweeds can contain undesirable substances, especially heavy metals and arsenic, which could be transferred to the insects, therefore enter the food production chain. The focus of this PhD project, as part of AquaFly, was to evaluate the suitability and safety of the seaweed-insect-fish food production chain, by studying the transfer of both nutrients and undesirable substances along the food chain. Several species of seaweeds from Norwegian waters were screened for their chemical profile. The seaweed species studied contained both nutrients and undesirable substances (heavy metals and arsenic); the concentrations thereof were highly dependent on species ...