New report points to animal welfare risks in pole-and-line tuna fisheries

The study, conducted through video material from the main capture countries, focuses on the treatment of several small and large tuna species. It found that although the pole-and-line method targets individual fish and avoids bycatch, many tuna suffer from long exposure to heat and air, are injured by hard deck surfaces and are often not properly stunned before slaughter.

Carefish/catch said observations onboard established that many fish were left to die slowly, asphyxiating without effective stunning or killing. It added that while some animals were hit with a stick, the method was often imprecise or repeated, and often lacked a follow-up step like bleeding.

The report identifies two key welfare challenges: First, prolonged air exposure, whereby if not immediately stunned, fish are exposed to air on deck for hours, crushed under others. And second, there’s often insufficient stunning methods, with large tuna sometimes stunned with a wooden club – a method that was found to be imprecise. Additionally, the high throughput makes individual stunning challenging, especially for small tunas.

“There’s a common belief that traditional methods are automatically better for animal welfare, but this study shows that even low-impact fisheries need to improve,” said Fausta Borsani from the Carefish/catch Consortium. “Simple changes like proper stunning and immediate bleeding can make a huge difference, both for the animals and for product quality.”

The report makes a number of practical recommendations, including:

• Standardise and train crews in effective stunning and killing procedures
• Introduce better tools for ethical slaughter, such as percussive stunning followed by bleeding or post-stunning ice treatment
• Reduce the time tunas spend out of water before being killed
• Keep the deck moist and cushioned to avoid physical damage
• Include welfare guidelines in fisheries certifications and improvement projects