Turbot

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 - both are seen by the aquaculture industry as a strategic ingredient¹ to be used efficiently and replaced where possible.

Globally the FM and FO used in aquafeeds is 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 2022^{1, 2, 3}.

IFFO The Marine Ingredients Organisation, formerly the International Fishmeal and Fish Oil Organisation or IFFO)⁴, estimates that on average producing 1 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 and FO 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 produced⁵.

Perhaps the most important mitigation measure is to ensure that marine products such as FM and FO used to manufacture aquafeed come from legal, reported and regulated fisheries. Such fishery products can demonstrate that their sourcing adheres to the United nations and Agriculture Organisation (UN FAO) “Code of Conduct for Responsible Fisheries”⁶, known as CCRF, through several mechanisms:

• The Marine Stewardship Council (MSC)⁷ which certifies fisheries to an international standard based on FAO best-practice requirements
• IFFO RS Global Standard for Responsible Supply (IFFO RS)⁸ 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 FishSource⁹ or FisheryProgress¹⁰ 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 also provide 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) produced in the rest of Asia (and this is from by-products). Given that Asia as a whole produces around 1.5 million tonnes of FM there is considerable room for improvement, both in the area of fisheries management and in FM certification uptake². 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 area of on-going 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.

Turbot Feed

Careful management of food and feeding regimes are important to the success of 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).

Turbot have a high protein dietary requirement and are generally fed commercial pelleted aquafeeds. Marine flatfish/turbot aquafeeds are high in FM and FO, but also include vegetable materials (e.g. soy-based)¹⁵ that are increasingly substituting ingredients FM and FO.

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 fish⁵. Farmed turbot has an FCR of 1.8 (but this value includes losses during grow-out so actual feed use is likely be more efficient)¹⁶, and in RAS and PAS there is generally more efficient use of feed¹⁷. Still, these values are higher than other major farmed species such as Atlantic salmon, where typical marine ingredient inclusion levels and FCRs are lower.