Can Fish Actually Feel Pain?
The short answer: Yes
The long answer: It’s complicated
The question of whether fish feel pain has been debated for decades. However, the current evidence suggests that fish are capable of experiencing pain, though it may differ than the pain that humans experience.
The current debate is not whether fish react to harmful stimuli. Scientists confirmed long ago that fish can detect injury and respond to it. The more complex question is whether fish consciously experience pain rather than merely exhibiting automatic reflexes.
Pain vs Nociception
To understand this debate, it’s helpful to distinguish between two related concepts: nociception and pain.
Nociception is the nervous system’s ability to detect and react to harmful stimuli, such as extreme heat or injury. All vertebrates experience nociception.
On the other hand, pain is the subjective experience associated with injury or harm. It is not simply detecting damage to the body. It is the unpleasant feeling that motivates an animal to avoid that damage in the future.
For example, if you accidentally touch a hot stove, you will quickly pull your hand away before your brain has time to actually process the pain. That reflex is nociception. The burning sensation that follows is pain.
The challenge for scientists is that we cannot directly measure another animal’s subjective experience. Instead, we must infer it from anatomy, physiology, and behavior.
What Does the Evidence Show?
Researchers have identified nociceptors in several fish species, including rainbow trout. But the evidence extends beyond just anatomy.
Studies have found that injured fish often exhibit behavioral changes that seem to go beyond simple reflexes. These changes may include:
Reduced feeding
Altered swimming behavior
Rubbing injured body parts against surfaces
Avoidance of locations associated with negative experiences
Taken together, these findings have led many scientists to conclude that fish are capable of experiencing more than a simple reflexive response to harm.
Do Fish Feel Pain the Same Way Humans Do?
Probably not.
Fish are anatomically very different than humans. This fact has led some researchers to conclude that fish may not experience pain in the same way mammals do. Others argue that different brain structures can still allow for conscious experiences, including pain.
However, the question is not whether fish can experience suffering, as the evidence shows that fish respond negatively to negative stimuli, and actively try to avoid it. Rather, the question centers on the nature and complexity of that suffering.
But does the way they experience suffering really matter? Dogs, cats, birds, and humans all experience the world differently, yet we do not disregard their suffering simply because it differs from our own.
Why This Matters
It is estimated that each year, more than 2 trillion wild fish are caught and 124 billion fish are farmed globally.
Written out numerically, that totals 2,324,000,000,000 fish slaughtered each year.
Fish represent one of the largest groups of vertebrate animals directly affected by humans, yet discussions about animal welfare frequently focus on mammals and birds, while fish receive comparatively little attention.
However, this is beginning to change. In recent years, animal welfare organizations, researchers, and policymakers have brought increasing attention to issues such as slaughter methods, stocking densities in aquaculture, and the treatment of fish during capture and transport.
A Better Question
When people ask whether fish feel pain, they are often looking for a simple yes or no answer.
Unfortunately, we cannot step inside a fish’s mind or ask them what they are experiencing. What we can do is look at the evidence. The anatomical structures and behavior patterns observed by scientists strongly suggest that fish can experience negative states associated with injury and harm.
Perhaps the more important question is not whether fish experience pain exactly like humans do. It is whether we should take the possibility of their suffering seriously. Given the evidence available today and the vast number of fish affected, the answer to that question seems increasingly difficult to ignore.
Take Action!
According to Animal Charity Evaluators, these are a few of the organizations making the biggest impact for fish welfare. I highly recommend checking out the info on these websites and supporting their mission to bring to light the suffering these animal experience.
Together, we can create a more humane and compassionate world for everyone. Including our underwater friends.
Fish Welfare Initiative (FWI) works to reduce the suffering of farmed fishes in India, China, and the Philippines.
Aquatic Life Institute (ALI) works globally to improve the welfare of farmed and wild caught aquatic animals.
Shrimp Welfare Project (SWP) works to improve the welfare of farmed shrimps in Central and South America, Southeast Asia, and India.