New guide to rainbow trout welfare launched
An operational welfare indicator (OWI) protocol for farming rainbow trout in seawater has been published by the Berlin-based Centre for Aquaculture Progress, which works to accelerate the adoption of science-based and sustainable fish welfare improvements in European aquaculture.
The OWI protocol, which can be accessed on the Centre's website as either a downloadable PDF or an online interactive version, is free and publicly available.
The protocol is for farm personnel doing routine welfare monitoring, and for certification bodies, auditors, and buyers. It is designed to align with the welfare monitoring and assessment requirements of key certifications, such as RSPCA Assured and Aquaculture Stewardship Council.
The Centre for Aquaculture Progress’s co-executive director Naomi Murn, said that as far as the Centre’s members were aware, it is the first assessment tool of its kind for farmed rainbow trout in seawater systems.
Key collaborators
The protocol was developed in close collaboration with Marco Cerqueira of the Centre of Marine Sciences of the Algarve, Portugal.
Jonatan Nilsson and Angelico Madaro at Norway’s Institute of Marine Research also provided detailed review and extensive contribution to the protocol, and the Centre for Aquaculture Progress received feedback from a number of other industry stakeholders, including individuals from certification bodies, academia, NGOs, and producers.
Operational Welfare Indicators (OWIs) are standardised assessment tools designed for routine implementation in commercial aquaculture. Unlike some other proxy measures, such as plasma cortisol concentrations, that require laboratory analysis, OWIs enable practical on-farm assessment.
The protocol includes 33 OWIs across three categories - 14 individual-based indicators, five group-based indicators, and 14 environmental indicators.
It also includes scoring systems for each indicator, split into four tiers comprising levels 0-3, and reference images and scoring guidance for practical field application.
“Rainbow trout, like other teleost fish, are animals capable of experiencing pain and stress. Ensuring their welfare during production requires systematic monitoring through OWIs,” the Centre for Aquaculture Progress states on its website.
Shared priorities
“The increasing focus on OWI implementation reflects priorities shared across the aquaculture value chain - from producers, certification bodies, and seafood buyers, to consumers, governments, and NGOs - and aligns with broader international standards for health monitoring.
“By improving welfare outcomes, producers simultaneously achieve better growth, survival, robustness, and production efficiency, while meeting regulatory requirements and evolving consumer expectations.”
The Centre for Aquaculture Progress team includes Sean Black, former senior scientific officer (aquaculture) for RSPCA Assured. Along with its OWI protocol for rainbow trout, the Centre is developing OWI guidance for sea bream and sea bass.
