Atlantic Halibut

Hippoglossus hippoglossus


Fish Meal and Fish Oil

Marine ingredients such as Fishmeal (FM) and Fish Oil (FO) provide nutrients that often cannot be found in other feed materials (e.g. particular amino acids, vitamins and minerals), and they are essential constituents of many aquafeeds. FM and FO are a finite resource and are seen by the aquaculture industry as a strategic ingredient to be used efficiently and replaced where possible1.

The ratio of wild fish input (via feed) to total farmed fish output fell by more than one third between 1995 and 20072. A continuing decrease in FM and FO inclusion in aquafeeds is predicted as feed companies develop formulations which increasingly reduce the use of these marine ingredients.

Globally, the FM and FO used in aquafeeds are instead increasingly derived from fishery and aquaculture processing by-product; the utilisation of these by-products as a raw material for FM and FO production is in the region of 25%-35% and this trend will continue; it is expected to rise to 49% by 20221.

IFFO The Marine Ingredients Organisation3 (formerly known as The International Fishmeal and Fish Oil Organisation or IFFO) estimate that if aquaculture is taken as a whole, producing one tonne of fed farmed fish (excluding filter feeding species) now takes 0.22 tonnes of whole wild fish. This essentially means that for every 0.22 kg of whole wild fish used in FM production, a kilo of farmed fish is produced; in other words, for every 1 kg of wild fish used 4.5 kg of farmed fish is produced4.

Perhaps the most important mitigation measure is to ensure that products such as FM and FO used to manufacture aquafeed come from legal, reported and regulated fisheries. Such fishery products can demonstrate their sourcing adheres to the United Nation Food and Agriculture Organisation (UN FAO) “Code of Conduct for Responsible Fisheries”5, known as CCRF, through several mechanisms:

  • The Marine Stewardship Council (MSC)6 which certifies fisheries to an international standard based on FAO best-practice requirements
  • IFFO RS Global Standard for Responsible Supply (IFFO RS)7 which certifies FM and FO through a process which includes the assessment of source fisheries against a set of CCRF-based requirements
  • Information platforms such as FishSource8 or FisheryProgress9 which provide information and analysis without a certification or approval rating

Currently around 1.9 million tonnes of FM production is certified as either IFFO RS or MSC – representing about 40% of global production; most of this comes from South America, but Europe and North America are providing significant volumes, and North Africa currently has certified production. Currently there is no certified FM product produced in China and only very small quantities (less than 10,000 tonnes) are produced in the rest of Asia (and this is from by-products). Given that Asia produces around 1.5 million tonnes of FM, there is obviously considerable room for improvement in both fisheries management and certification uptake10.

Aquaculture certification schemes also require that fish products used in feeds are not on the International Union for Conservation of Nature (IUCN) red lists11 of threatened species or the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)12 lists of endangered species.

GM Feed Ingredients

The use of genetically modified (GM) vegetable ingredients in animal feedstuffs (including aquafeed) is an ongoing area of debate13. Whilst some contend that GM soy can help support current levels of aquaculture, global attitudes and consumer perceptions about the use of Genetically Modified Organisms (GMOs) vary in different parts of the world, with North American markets being far less averse than European ones. However, their use in all livestock feed is widespread, and in the EU food from animals fed on authorised GM crops is considered to be as safe as food from animals fed on non-GM crops14.

Atlantic halibut Feed

Careful management of food and feeding regimes are important to the success of Atlantic halibut aquaculture. To reduce wasting aquafeed on farms, efficient feed use can be monitored and should comply with levels set in certification standards. The indicators used can include the Feed Conversion Rate or FCR (the amount of feed an animal requires to gain a kilogram of body weight), economic feed conversion ratio (eFCR), maximum fish feed equivalence ratio (FFER), or protein efficiency ratio (PER).

Atlantic halibut have a high protein dietary requirement and are generally fed commercial pelleted aquafeeds. Marine flatfish/Atlantic halibut aquafeeds are rich in FM and FO but can also include vegetable materials (e.g. soy-based)15. Some halibut farmers, including the main UK producer16, use feeds where FM and FO are derived from fishery and aquaculture processing by-product.

Figures are available on the marine ingredient utilisation in aquafeeds for farmed marine fish. In 2015 it was estimated that for every tonne of marine fish produced in aquaculture 0.53 tonnes of whole wild fish were used. This is a significant reduction from 2000 levels which were around 1.48 tonnes of wild fish4. Farmed Atlantic halibut has an FCR of approximately 2.016 (but this value includes losses during grow-out, so actual feed use is likely be more efficient)17, and in both RAS and PAS there is generally more efficient use of feeds18. Still, these values are higher than other major farmed species such as Atlantic salmon, where typical marine ingredient inclusion levels and FCRs are lower.


  1. IFFO
  2. Naylor, R.L., et al, 2009. Feeding aquaculture in an era of finite resources. Proceedings of the National Academy of Sciences, 106 (36), p15103-15110
  3. IFFO
  4. IFFO 
  5. FAO
  6. MSC
  7. IFFO RS
  8. FishSource
  9. FisheryProgress
  10. IFFO
  11. IUCN
  12. CITES
  13. Sissener, N.H., et al, 2011. Genetically modified plants as fish feed ingredients. Canadian Journal of Fisheries and Aquatic Sciences, 2011, 68(3) p563-574
  14. FSA
  15. Berge, Gerd & Grisdale-Helland, B & J. Helland, S. 1999. Soy protein concentrate in diets for Atlantic halibut (Hippoglossus hippoglossus). Aquaculture. 178. 139-148. 10.1016/S0044-8486(99)00127-1.
  16. Gigha Halibut Pers comm.
  17. IFFO pers. comm.
  18. SARF