Monday June 9, 2025
Earth.com —
Each year, more than two trillion wild and farmed fish are killed to feed humanity. Their deaths often go unnoticed. Yet beneath the surface is a simple biological fact: fish can suffer.
Rainbow trout, a species farmed and consumed across the globe, experience not just death – but a prolonged and intense form of distress when killed by air asphyxiation.
A new study published in the journal Scientific Reports shines a light on this pain and offers a pathway to reduce it.
Fish pain needs better measurement
Unlike environmental impact or public health, animal suffering lacks a universal metric. There are no equivalents to carbon footprints or life years lost. To address this, scientists developed the Welfare Footprint Framework (WFF).
This tool measures pain in minutes, allowing researchers to compare welfare outcomes across species and conditions. The research team applied this method to trout slaughter, where air exposure is still a widely used technique.