Trout, Rainbow

Oncorhynchus mykiss

Method of production — Farmed
Production country — UK
Production method — Freshwater pond without recirculation
Picture of Trout, Rainbow

Sustainability rating two info

Sustainability overview

Trout farming was introduced into the UK in the 1950’s, and now there are over 300 trout farms. Rainbow trout is the most popular farmed species of trout, with most of production occurring in a variety of enclosures in freshwater. Farming of trout in ponds and raceways allows for greater control so there are generally fewer impacts to the surrounding environment that in open net pen production. For example the effects of effluent discharge are limited due to sedimentation and treatment practices in place. Trout are carnivorous species that are reliant on fishmeal and fish oil from wild capture fisheries to make their feed. Rainbow trout farmed in freshwater is a good choice.

Feed Resources

Criterion Score: 0 info

Trout is a feed species that relies on commercial pelleted feed. The ingredients used to make the feed are traceable and responsibly, if not sustainably sourced. Feed formulations have changed and continue to do so resulting in less wild fish being included in feeds. These marine proteins and oils are being replaced with vegetable alternatives such as soy and rapeseed oil. The amount varies between countries and feed formulations but the average feed still includes a significant amount of fishmeal and fish oil, MCS would like to see this fisheries supplying the feed being certified as sustainably managed.

Environmental Impacts

Criterion Score: 1 info

As trout farms in this assessment are located adjacent to a freshwater river which supplies water to the production ponds and raceways freshwater depletion is not an issue as the systems are a flow through set up then return water to source. There is no mention within the Quality Trout standard of habitat protection prior to pond construction, therefore there is uncertainty regarding habitat impacts.

Fish Health and Welfare

Criterion Score: 1 info

Quality Trout standards cover both fish welfare and slaughter. A Veterinary Health Plan is required which covers transport and staff are required to be trained in welfare practices.


Criterion Score: 4 info

The management of trout farming in freshwater spans 3 production countries - Scotland, England and Wales, each with their own regulatory bodies. With regards to spatial planning, each country implements their own River Basin Management plans, this are river specific and do not cover all of the rivers that are utilised for trout farming at present.

Production method

Freshwater pond without recirculation

Rainbow trout is the most widely farmed trout species in the UK, It is farmed in freshwater ponds and raceways adjacent to a good water supply such as a river.


Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Anchovy, anchovies
Arctic char
Herring or sild
Horse Mackerel, Scad
Kingfish, yellowtail
Salmon, Atlantic (Farmed)
Salmon, Chum, Keta, Calico or Dog salmon
Salmon, Pink, Spring , humpback
Salmon, Sockeye , Red Salmon, Bluebacks, Redfish
Trout, Rainbow
Tuna, albacore
Tuna, skipjack
Tuna, yellowfin


A member of the salmonid family, rainbow trout are native to western North America and range from Alaska to Mexico. They can grow up to 120cm in length and live to an average age of 11 years. They prefer freshwater and require fast flowing water to breed


Quality Trout. UK standard issue. 5.6 1 11 2017. Available online at: Accessed 18/06/2019

FAO Cultured Rainbow trout factsheet. Available online at: Accessed 18/06/2019

FEFAC Soy sourcing guidelines. 2015. Available online at: Accessed 18/06/2019

Small scale trout farming. FAO. Available online at: Accessed 18/06/2019

Tacon. A, G, J & Metian, M. 2008. Global overview on the use of fish meal and fish oil in industrially compounded aquafeeds: Trends and future prospects. Aquaculture Volume 285, Issues 1-4, 7 December 2008, Pages 146-158

FAO. Aquaculture Feed and Fertilizer Resources Information System. Available online at: Accessed 18/06/2016

Scottish Fish Farm Production Survey. Scottish Government.2017. Available online at: Accessed 20/06/2019

River Basin Management Plans: 2015.UK government. Available online at: Accessed 24/06/2019

COUNCIL DIRECTIVE 92/43/EEC (1) of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. Council Directive 2006/66/EC . EUR Lex. Available online at : Accessed 24/06/2019

Council Regulation (EC) No 708/2007 of 11 June 2007 concerning use of alien and locally absent species in aquaculture. EUR Lex. Available online at: Accessed 24/06/2019