Credit: Culum Brown

A leading expert in fish behaviour argues that our fundamental understanding and assessment of animal welfare must be changed to consider fish, or risk continued catastrophic impact on their welfare, in an article published today in Animal Sentience.

Animal welfare is assessed on the basis of whether animals think and feel and therefore their potential to suffer, however how we assess animal sentience is still debated. "There is growing concern around the world about how we treat animals, particularly as part of the food production line.

In Australia we have had a massive change in attitude towards animal welfare but for some reason the momentum stopped at the water's edge," said Associate Professor Culum Brown from the Department of Biological Sciences at Macquarie University.

Scientists have definitively shown that some species of fish feel pain, but there are more than 30,000 species of fish, and so the question is whether all fish species feel pain.

While researchers can't be certain what another animal is feeling or thinking, when they are dealing with uncertainty they often use the 'precautionary principle' to determine whether an animal is sentient.

"This approach is particularly common in environmental legislation, but it can equally be applied to animal welfare through the Animal Sentience Precautionary Principle (ASPP). We know that closely related species tend to share traits through common decent. If we know sentience exists in just a few species of fish, we can use phylogenetic inference to estimate their evolutionary history and determine its likely distribution across all fishes," said Associate Professor Brown.

If this approach is used, it soon becomes apparent that all fish likely feel pain just as humans do, and one of the fundamental issues with fish welfare is the sheer number of animals involved.

"This is really common sense from a risk-assessment perspective. Each year trillions of fish are killed in commercial fishing operations – this is greater than 1000 times more than mammals. The vast majority die horribly because there are no welfare regulations. So the consequences for getting this wrong are catastrophic from a welfare perspective," said Associate Professor Brown. The implications are quite startling and highlight the need to ensure fish are universally covered by animal welfare legislation.

"I think your average person would be shocked to discover that some states in Australia don't even include fish in their definition of 'animal' in animal welfare legislation," concluded Associate Professor Brown. "That means anyone can do anything to a fish with no fear of prosecution."

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More information: Brown C. A risk assessment and phylogenetic approach: Commentary on Birch on Precautionary Principle. Animal Sentience. October 2017. Birch, J (2017) Animal sentience and the precautionary principle. Animal Sentience 16(1) Brown C. A risk assessment and phylogenetic approach: Commentary on Birch on Precautionary Principle.. October 2017. Birch, J (2017) Animal sentience and the precautionary principle. Animal Sentience 16(1) animalstudiesrepository.org/cg … 219&context=animsent