Aquaculture: Scale and Stakes
Aquaculture now produces more seafood by weight than wild capture fisheries, making it the world's fastest-growing food production sector. Approximately 600 billion fish are farmed annually — more individuals than all terrestrial farmed animals combined. As fish sentience science has advanced dramatically in the 2020s, the welfare implications of aquaculture practices have attracted increasing scientific, regulatory, and consumer attention. 2025 marks a pivotal moment as new standards, technologies, and corporate commitments begin to reshape the industry.
600B
Farmed fish killed annually
90M+
Tonnes aquaculture production/yr
580+
Species under aquaculture
2025
EU aquaculture welfare guidelines
Fish Sentience: The Science in 2025
Scientific understanding of fish sentience has advanced substantially. The 2021 Cambridge Declaration update and subsequent research have strengthened the case that fish experience pain, fear, and stress in ways that matter morally.
Key Scientific Developments
- Fish possess nociceptors and opioid systems analogous to mammalian pain systems
- Brain imaging studies show fish exhibit conscious-like responses to noxious stimuli
- Fish learn to avoid conditioned stimuli causing pain — not merely reflexive
- Stress hormones (cortisol) spike during aquaculture procedures in patterns paralleling mammals
- Social stress, conspecific aggression, and predator cues cause measurable behavioral changes
- The 2023 WOAH acknowledgment of fish sentience as a working assumption was a landmark shift
Regulatory Response: The EU's 2025 aquaculture welfare guidelines — the first specific EU guidance on fish welfare — represent a regulatory recognition that fish sentience is sufficiently evidenced to justify welfare standards. Norway, the UK, and Switzerland have also updated fish welfare regulations.
Species-Specific Progress
Atlantic Salmon
Salmon welfare has received the most attention due to the industry's economic scale (Norway, Chile, Scotland, Canada). Key advances in 2025 include wider adoption of operational welfare indicators (OWIs), improved sea lice treatment protocols, and expanded use of electric stunning before slaughter.
Stunning Technology: Percussive stunning (AQUI-S) and electrical stunning systems are now used by major Norwegian and Scottish producers. RSPCA Assured and ASC (Aquaculture Stewardship Council) certification now requires effective stunning. This represents a genuine step change from earlier live chilling or asphyxiation methods.
Tilapia
Tilapia is the most widely farmed fish globally, primarily in tropical developing countries. Welfare standards are far less developed than for salmon. 2025 sees emerging certification frameworks and improved guidance on stocking density, water quality, and humane slaughter for tilapia operations in major producing countries.
Shrimp
Shrimp welfare remains highly contested — shrimp sentience evidence is weaker than for fish, but the scale (hundreds of billions annually) means even small probability of sentience creates large expected welfare impacts. Progressive retailers are incorporating shrimp welfare criteria into sourcing policies.
Carp
Carp dominate aquaculture by volume (primarily Asia). Welfare standards for carp are minimal but awareness is growing, particularly in China which produces over 70% of global carp.
Key Welfare Challenges
| Challenge | Species Affected | 2025 Status |
|---|
| Pre-slaughter stunning | Salmon, trout, sea bass | Progressing in EU/Norway/UK |
| Sea lice infestation | Salmon | Improved treatment protocols |
| Crowding/handling stress | All species | Density guidelines improving |
| Water quality management | All species | Sensor technology advancing |
| Genetic welfare issues | Salmon, carp | Emerging concern |
| Transport welfare | Live fish trade | Very limited standards |
| Shrimp eyestalk ablation | Shrimp (broodstock) | Some phaseout commitments |
Eyestalk Ablation: In shrimp farming, female broodstock are routinely blinded (eyestalk ablation) to accelerate reproduction. This painful procedure is performed without anesthesia on billions of shrimp annually. Some retailers and certification bodies have moved to prohibit it; most have not.
Certification and Standards Progress
Aquaculture certification schemes have been the primary driver of welfare improvements in the sector. In 2025, multiple schemes have updated welfare criteria.
Key Certification Bodies
- ASC (Aquaculture Stewardship Council): Updated 2024 standard includes welfare indicators and stunning requirements for salmon
- RSPCA Assured: UK-specific; most comprehensive welfare requirements for salmon and trout
- GlobalG.A.P.: Broad coverage; welfare module being strengthened
- Best Aquaculture Practices (BAP): US-oriented; welfare criteria for shrimp and finfish
- Organic certifications: Various national organic standards include welfare provisions
Retailer Commitments: Major UK, EU, and US retailers have made aquaculture welfare commitments in 2024-25, primarily for salmon. These include stunning requirements, lice threshold limits, and third-party welfare auditing. Corporate commitments have historically driven faster change than regulation in aquaculture.
Advocacy Organizations and Future Direction
Leading Advocates
Aquatic Life Institute
Fish Welfare Initiative
Compassion in World Farming
Humane Slaughter Association
RSPCA (aquaculture)
Shrimp Welfare Project
Priority Areas for 2026
- Extension of stunning requirements to sea bass, sea bream, and other farmed species
- Shrimp eyestalk ablation phaseout across major certification schemes
- China engagement: improving welfare standards for carp (>70% of global volume)
- Operational welfare indicators standardization for industry self-assessment
- Welfare requirements integrated into major import market regulations (EU, UK, US)
Aquaculture welfare represents one of the highest-leverage areas in global animal welfare improvement. The combination of scientific advances confirming fish sentience, growing regulatory attention, and increasingly engaged retail buyers creates real momentum. The challenge is ensuring welfare improvements keep pace with the sector's continued rapid expansion.