In just three weeks since its publication on 5 June 2025, our latest study in Scientific Reports has drawn attention far beyond our expectations. According to the journal’s metrics the article has already reached over 12,000 accesses and recorded an Altmetric score of 416—an exceptional level of engagement for a newly published scientific paper.

Even more surprising is the widespread and international media coverage it has received, with the study being reported across major science platforms and local news outlets in multiple countries. This response underscores a growing global interest in the welfare of aquatic animals—a subject too often overlooked in mainstream discourse.

At the heart of the paper is the application of the Welfare Footprint Framework (WFF) to quantify, in time-based terms, the distress experienced by rainbow trout when slaughtered by air asphyxiation—a method still widely used in fisheries and aquaculture. The findings are sobering: each trout endures an estimated 10 minutes of moderate to extreme pain (with a credible range of 1.9 to 21.7 minutes) during the slaughter process. Standardized per kilogram, this equates to an average of 24 minutes of significant pain per kg, with upper estimates reaching 74 minutes/kg.

One of the most promising contributions of the study lies in its cost-effectiveness modeling. We found that investment in stunning equipment—if applied effectively—could avert between one and twenty hours of moderate to extreme pain per USD of capital cost. Yet these benefits depend on reliable implementation. In practice, many commercial operations continue to face difficulties with stunning—due to equipment variability, improper positioning, or lack of procedural oversight—often reducing the expected welfare gains.
Perhaps even more critical are the pre-slaughter stressors: crowding, transport, and handling may expose fish to prolonged distress lasting hours or even days—potentially outweighing the pain and distress experienced during slaughter. Fortunately, the WFF is designed to assess these phases as well, helping identify the most impactful intervention points to reduce suffering across the entire production chain. Ongoing work is quantifying now the welfare impacts of these preslaughter phases.

The rapid and widespread interest in this study reaffirms that animal welfare matters deeply to a growing segment of the public. It also highlights the power of a scientifically grounded framework—like the Welfare Footprint Framework—to translate complex, subjective experiences into easy-to-understand and actionable data that can inform more compassionate decisions.