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State of the art

What works today — and where the gaps remain.

An evidence-based view of slaughter and stunning practice, not an emotional one. We map current methods, identify the practical gaps, and frame the questions we intend to answer.

Current methods & their strengths

  • Electrical stunning — scalable for many small/medium farmed fish.
  • Percussive stunning — effective for larger individual fish.
  • Existing standards (e.g. WOAH) give a direction of travel.
  • Ice-slurry / chilling and manual checks remain common baselines.

Where the gaps remain

  • Species-specific stunning parameters.
  • Site-specific water conductivity & electrical settings.
  • Verification of insensibility and recovery risk before killing.
  • Affordability for small / low-resource operators.
  • Field deployment on real farms and vessels.
Open research questions

We begin with questions, not assumptions.

These shape the Phase 1 problem map, the welfare-indicator framework, and the pilot design.

Welfare validation

  • Which indicators are reliable for each species?
  • How can external signs be validated against stronger measures?
  • What failure modes are most dangerous?

Engineering

  • Which sensors are robust in wet, harsh environments?
  • Can parameters be logged without modifying existing stunners?
  • Can the system work fully offline?

Adoption

  • What cost is acceptable for small farms?
  • What evidence would certifiers trust?
  • What training do operators need?

Pilot design

  • Which species should be first?
  • Which site type is easiest and highest-impact?
  • What 6-month result would justify expansion?
References

Grounded in public evidence.

Key sources informing our problem framing. Figures are used carefully and cited.

  1. 01
    Coefficient Giving — Humane Fish Slaughter RFP

    Scale of the problem and the ~0.5% reliably-stunned estimate; emphasis on verifiable, scalable, practical solutions.

  2. 02
    Fishcount — Farmed fish slaughtered each year

    Independent estimate of ~130 billion farmed finfish slaughtered in 2022 (range 86–180 billion).

  3. 03
    WOAH — Welfare aspects of stunning & killing (aquatic)

    Electrical stunning requires sufficient current, duration, and frequency; water conductivity makes site-specific parameters essential.

  4. 04
    Frontiers — Humane slaughter in Mediterranean sea bass & bream

    Among the largest developed-world finfish sectors that still do not stun most production — supporting an Italy/Mediterranean pilot.

  5. 05
    PMC — Estimating global numbers of farmed fishes killed annually

    Context on non-recommended killing methods (air asphyxiation, ice-water chilling, CO₂, exsanguination without stunning).

  6. 06
    Electrical stunning reviews & machine-vision in aquaculture

    Placeholder — add the specific reviews + EFSA species opinions once the technical-context page is finalized.