“Coke on fish gills is as dumb as it sounds", Dr. Solomon David, aquatic ecologist, Nicholls State University

Northern pike  Photo by Darcy Cheek /Postmedia

"We provide the first evidence that counters the growing popularity of using carbonated beverages to stop bleeding in angling-caught fish."                     "We found no benefit or disbenefit with pouring carbonated beverages over the gills of northern pike but it is possible there are longer term impacts."  "These findings provide direct scientific evidence that the use of carbonated beverages does not curtail bleeding from gills, which is counter to anecdotal observations made by recreational anglers that use this technique. Overall, our study debunks the assertion."                                                                                                          Carleton University researchers

Research funded by Muskies Canada and by fishing guide John Anderson and undertaken by the fish ecology conservation and physiology laboratory of Carleton University, led by graduate student Alexandria Trahan, appears to have concluded that a technique to ease bleeding in injured fish that has become popular with anglers has more resemblance to an urban myth than it does a folk remedy to curtail bleeding and discomfort in fish that have sustained injury either as a result of the angler's actions or other misadventure.

And though veteran fishing guide and owner of Ottawa River Musky Factory John Anderson was partially responsible for putting the research into motion, spurred on no doubt by his belief in the healing power of carbonated liquid on fish, his commitment to the use of Diet Coke to help stop muskellunge bleeding from the mouth, throat or muscles around the gills is secure. On the basis of his own experience with the use of the technique on 18 different occasions.

While on a fishing trip four years earlier accompanied by writer and outdoorsman Gord Pyzer, the method was first brought to his attention when it was demonstrated to him. He gave due credit to the senior manager in the Ministry of Natural Resources and Forestry when he was informed by this man who makes use of spring water, supersaturated with carbon dioxide in cauterizing hook wounds in a fish's mouth, throat or gills, who swore by its efficacy.

In the event, researchers from the lab of biology professor Steven Cooke undertook a scientific study of the controversial and popular belief in the usefulness of Diet Coke as a first aid for injured fish, where advocates insist that carbon dioxide in soda drinks constricts a fish's blood vessels to halt bleeding. Critics of the method on the other hand, label it as pop science for the gullible. Those who want to catch these fish for sport, but are committed to releasing them back to the water. Salving their consciences in the belief that the remedy works. In their analysis the Carleton scientists discovered that in the first 20 minutes following the application of pop to injured gills of northern pike, nothing occurred.

Last year, led by graduate student Alexandria Traham from the lab, 145 northern pike were caught in the
Rideau River system to use as subjects where gill injuries were simulated with the use of pliers removing a one-centimetre section of gill. A carbonated beverage was then applied; Coca-Cola, Mountain Dew or carbonated lake water. Nothing was applied to a control group of fish. The experiments were conducted in May and August in assessing whether changes in water temperature might affect the outcome.

Scientists observed and recorded what happened to the bleeding of the injured fish held in a water-filled tank for 20 minutes -- finding that Mountain Dew as well as the other carbonated drinks produced no discernible effect whatever. No difference was noted, according to the researchers, between the fish in the control group and those that had been treated with a soft drink. Bleeding failed to stop sooner, and nor did the fish bleed less.

A possible explanation was put forward, researchers suggesting that when anglers lift a fish from the water to apply a soft drink to the fish wounds, air exposure induces hypoxia which in turn slows the heart rate of the fish. "The pop does work at the right place and the right time", insisted Mr. Anderson who didn't dispute the Carleton study, but felt that the researchers would have done better to avoid using sensitive gill injuries in their assessment of the value of the technique.

John Anderson of the Ottawa River Musky Factory says the Carleton research has not changed his mind about the value of Diet Coke as a way to assist muskellunge bleeding from the mouth, throat or muscles around the gills. He said he had successfully used the technique 18 times. Photo by Tony Caldwell /Postmedia

The Least Among Us?

Normal exploratory behaviour -- Troy University

"The neurochemistry [of fish] is so similar [to that of humans] that it's scary."
"[While we tend to consider fish simple organisms] ...there is a lot we don't give fish credit for."
Julian Pittman, biologist, Troy University, Alabama

Depressed fish -- Troy University

"You can tell. Depressed people are withdrawn. The same is true of fish."
"Fish perception and cognitive abilities often match or exceed other vertebrates. Fish have a high degree of behavioral plasticity and compare favorably to humans and other terrestrial vertebrates across a range of intelligence tests.”
"The big issue here is that people don't treat fish the same way as they do other animals. It's complicated, but it boils down to the fact that most people just don't understand them and can't relate to them. If you don't have that connection, you are less likely to feel any empathy."
"Each animal is unique, has an identity and a personality. Each is special [so] animals should be treated with respect, and we have a duty of care towards them that demands that we reduce pain and suffering wherever possible."
"[Give your fish a one-meter tank] with lots of plants and stuff. A goldfish bowl, for example, is the worst possible situation."
Culum Brown, Department of Biological Sciences, Macquarie University, Sydney, Australia

"One of the things we're finding, that fish are naturally curious and seek novel things out."
Victoria Braithwaite, professor of fisheries and biology, Pennsylvania State University

(BENSON KUA)

It doesn't necessarily take the observational skills of an ichthyologist to be able to discern when fish are lively and interested in what's going on around them, as opposed to behaving in a decidedly unhappy mood, uncharacteristic of healthy fish. Anyone who decides to maintain an aquarium for the pleasure of watching fish in perpetual motion, admiring their grace and beauty can surmise when fish behave in ways that don't reflect the normal that they can be dissatisfied with their lives. And since their lives are circumscribed to the dimensions of the container they're in, the quality of that aqua-centric environment and the stimulants within it can be key.

Now, new research is informing biologists about the brains and habits and emotions that fish, a species of animal that most people would attribute no reactive capacity to despite ample evidence to the contrary -- think, for example of desperate measures fish take to survive capture, struggling against the prospect of death -- that fish do indeed have emotions and react to their environment and in ways amazingly close to resembling how humans themselves perceive and react. The very idea of fish cognition represents a whole new era of animal research.

Dr. Pittman is working on the development of medications in the treatment of depression, and his observations about fish reactions can lead the way to new discoveries that will, in the final analysis, be useful for medical treatment of depression in humans. His observations also, on the other  hand, point out how needful fish too are to avoid boredom and give quality to their lives when they are in particular trapped in an environment shrunk to a size nature never meant for them, and far indeed from their usual habitat.

Fish undergo testing with a protocol named the "novel tank test", and Dr. Pittman so readily identifies their depressive state that it brings a challenge as well as enjoyment to working with them. The tank test represents a zebrafish dropped into a new tank. When five minutes elapses it is discerned to be depressed if it swims in the lower half of the tank, but if it swims instead in the upper portion of the tank, exploring its new environment this is taken to be a reliable indication that the fish is not depressed.

According to Dr. Pittman, the amount of time the fish spends at the bottom of the tank as opposed to the top, indicates the severity of its depression. The zebrafish, in reacting to its new, depressing environment will lose all interest in normal life, including food, toys and exploration, reflecting the very same disinterest that depressed people display in their lives. According to Professor Braithwaite, the issue most responsible for depression is lack of stimulants in their environment.

She studies fish intelligence and preferences. Some fish have been demonstrated to be capable of using tools,while others are able to recognize faces. Dr. Braithwaite speaks of enriching the fish environment with ample plants for nibbling and objects to swim through and around, to decrease stress and increase brain growth. As well, according to Dr. Brown, vigilance with respect to water quality is vital to ensure a stable and oxygen-rich environment.

Tippi’s happy. Edible plants coming soon. (ROBBY BERMAN) From: Big Think