Absolutely, fish can get seriously stressed by traumatic situations, and the effects can last for some time in some cases.
This is why fishing, including catch-and-release fishing, is not harmless family fun. Fish have nerves, just like cats, dogs, and humans, so they can feel pain. Hooked fish endure not only physical pain but also terror. When they're removed from their natural environment, they start to suffocate.
Yes, fish feel pain
A significant body of scientific evidence suggests that yes, fish can feel pain. Their complex nervous systems, as well as how they behave when injured, challenge long-held beliefs that fish can be treated without any real regard for their welfare.
The nociceptor then sends an electric signal to the brain, where the psychological experience of pain manifests. Fish have numerous nociceptors in their mouths and thus getting hooked is certainly a painful experience for them.
The U.S. military has seen this reaction to stress in its working dogs. Its veterinarians say that about 5 percent of those that have served in Afghanistan and Iraq suffer from “canine PTSD,” which can make some dogs aggressive, timid or unable to do their jobs.
Commonly thought of as a human response to danger, injury and loss, there is growing evidence that many animals show lasting changes in their behaviour after traumatic events.
Free-living wild animals regularly experience intensely life-threatening predator encounters and are frequently physically traumatized as a result.
Fishing Gear Hurts Wildlife
Every year, anglers leave behind a trail of tackle victims that includes millions of birds, turtles, cats, and other animals who suffer debilitating injuries after they swallow fishhooks or become entangled in fishing line.
So, Does Catch and Release Hurt the Fish? The short answer is “yes, it does.” Whether through the physical sensation of pain or a somewhat decreased chance of survival, catch and release fishing does still hurt fish.
There's nothing inherently wrong with holding a bass or other smooth-toothed fish by the lip. You have more control there than anywhere else. But you should keep that fish mostly vertical if you're holding with one hand, and support its rear end with the other hand if you want it to rest horizontally.
Fish are among the most abused animals on the planet, and while many people say fish don't feel pain, this couldn't be further from the truth. Though the scientific community has been slow to accept that fish feel pain, the vast majority of biologists and veterinarians now agree they do.
What is this? Stress! It isn't good for humans, and it definitely isn't good for fish. Stress on fish eventually result in its death.
To answer the original question, yes fish can be heart broken. There is plenty of evidence of this in clownfish. Often when a member of a long term pair dies, the other soon follows (maybe disease, though often not) or is never quite the same afterwards. This has also been seen in cichlids (specifically convicts).
Do fish heal from hook injuries? Hook wounds were detected in 100 percent of angled bass on the day of angling and were still observed on greater than 90 percent of bass seven days after capture. In May, 27 percent of hook wounds were healed within six days, but only 12 percent were healed within six days during July.
What is clear is that deeply hooked fish have much lower chances of survival than lip hooked fish. If a fish is gut hooked, you do get better survival by cutting the line rather extracting the hook, but the survival rate is still unacceptably low.
When a fish is brought up from deep water the rapid change in pressure causes the gases in the fish's body to expand. This results in a range of injuries that will most likely be fatal to the fish, and is known as barotrauma.
Summary: Catch and release does have an impact on the environment, as catch and release seemingly kills somewhere between 5%-30% of fish when solid catch and release best practices are being followed. Trout and salmon are on the higher end of mortality rates and more resilient fish are on the lower end.
So, yes, pressured fish can learn (or adapt) to avoid certain lures.
Although the shark will undoubtedly swim away as fast as possible when you release it, catch and release is harmful to sharks. Biologists have evidence of this. They have documented cases where sharks will swim away and die within a matter of minutes after fishermen release them.
A study finds that when some fish lose their chosen mates, they become more pessimistic.
First, behavioural responses to sensory stimuli must be distinguished from psychological experiences. Second, the cerebral cortex in humans is fundamental for the awareness of sensory stimuli. Third, fish lack a cerebral cortex or its homologue and hence cannot experience pain or fear.
Fish Have Feelings, Too: The Inner Lives Of Our 'Underwater Cousins' : The Salt Jonathan Balcombe, author of What A Fish Knows, says that fish have a conscious awareness — or "sentience" — that allows them to experience pain, recognize individual humans and have memory.
Just like with humans, there is no finite period for grief, as every animal responds differently to a loss. Many experts suggest that animal grief will run its course in weeks to months, but studies of other species of animals recognized grief in closely bonded wild animal communities that lasted for years.
The forms of maltreatment to which animals may be subjected have extensive parallels with the forms seen in children. Animals may be neglected or abused, physically, sexually, and emotionally.
Mammals share the same nervous system, neurochemicals, perceptions, and emotions, all of which are integrated into the experience of pain, says Marc Bekoff, evolutionary biologist and author. Whether mammals feel pain like we do is unknown, Bekoff says—but that doesn't mean they don't experience it.