Industrial aquaculture key terms and definitions

This factsheet is part of DeSmog’s Industrial Aquaculture Database.

Aquaculture: the practice of breeding, raising and harvesting aquatic organisms for food and other products.

Fed aquaculture: Farmed seafood which requires feed inputs, such as tilapia (omnivorous) or shrimp salmon, and sea bass (carnivorous).

Carnivorous aquaculture: Farmed seafood which requires feed composed fully or partially of animal products, such as fishmeal and fish oil. Carnivorous aquaculture includes salmon, sea bass, sea bream, trout, grouper and shrimps.

Non-fed aquaculture: Farming of species that are completely reliant on the natural food present in their captive environment, such as mussels and oysters. These systems typically do not have a direct negative impact on wild fish; however, intensive operations can have indirect effects on wild fish through habitat change and flow alteration.

Aquafeed: Feed for fed-aquaculture species which aims to provide all the nutritional requirements for the different life stages of a farmed fish. It is composed of a mix of vegetable and marine ingredients, such as soya, fishmeal and fish oil. 

Fishmeal: Ground tissue of un-decomposed whole fish, or trimmings (which are referred to as “by-products”). Takes the form of flour, pellets or granules and is considered unfit for direct human consumption, and is typically used as an ingredient for aquafeed or other animal feeds. It takes an average of four to five kilos of individual whole fish to make one kilo of fishmeal.

Fish oil: Liquid obtained through the pressing and centrifugation of cooked fish. Fish oil can be used for direct human consumption (supplements) and non-human consumption (animal feed, pesticides) and is a fishmeal by-product. It typically takes 20 kilos of whole small fish to make one litre of fish oil.

Fish In Fish Out ratio (FIFO): The ratio of farmed fish produced by farming to small pelagic fish that go into aquafeed as ingredients. When the FIFO ratio is higher than 1, a higher volume of wild-caught fish was used than the volume of farmed fish produced. 

Forage Fish: Generally small, oily fish which are typically low in trophic level and are eaten by larger fish, marine mammals and seabirds. For example, herrings, anchoveta, capelin, sardines, sardinella. Also called “small pelagic fish” or “low trophic level species”.

Reduction Fishery: A fishery that catches fish to “reduce” – i.e. process – them into fishmeal and fish oil, instead of for direct human consumption. These are generally small pelagic fish/forage fish like sardinella, herrings and anchoveta.