If you practice catch and release, the effect of gripping a fish by the mouth is maybe something many anglers haven’t considered. Is it safest to hold it vertically or horizontally? With a clamping scale?
A biologist and two veterinarians devised an experiment to see what, if any, harm was done by different ways of handling fish. Texas fisheries biologist Steven Bardin teamed up with Drs. Casey Locklear and Steven Mapel to fill in the lack of research on the best way to hold fish, according to Wired to Fish.
First, the team had to gather test samples. Using a private lake Bardin manages, they used electrofishing to gather trophy-sized bass between 2 and 6 pounds. The doctors then took x-rays of each fish being held in four positions: horizontally with a second hand for support, vertically, vertically with a fish scale, and vertically with the fish’s body weight applying downward pressure on the jaw.
The good news: none of these methods resulted in broken bones, according to the vets. They said the stress of being held by the mouth was spread among lower jaw bones, joints and soft tissue. “The weakest parts of the jaw are actually the soft tissue areas, not the bones,” said Dr. Locklear.
They did find that some fish sustained injuries with over-flexion and over-extension to the soft tissue areas. However, they don’t know the extent of the injuries or the recovery time. Fish with these injuries could swim away appearing normal. Bardin said further areas for research include whether the injury could affect a fish’s ability to forage, would the injury recur and how long the fish feels its effects.
The trio also found the size of the fish affects the likelihood of injury. Bigger isn’t be
“The jaw of the largest fish we radiographed actually made an audible ‘pop’ when it was placed into the exaggerated vertical position,” Bardin said, adding that this didn’t happen to smaller fish.
Bardin said he uses a hanging fish scale with a clip and was glad the experiment found using clips did not damage the fish’s joints. “The clips actually act as a pivot point, so as the fish move on the scale, it takes much of the pressure and force off of the jaw,” he pointed out.
In the end, the experiment revealed some tips to handle prized catches safely. Large fish require additional support with a second hand whether being held horizontally or vertically. Fish grips or hanging scales can also be used safely. Holding fish at an angle greater than 10 percent could possibly damage the jaw, and holding a fish vertically with too much pressure on the jaw is not recommended. Even if a fish is injured by a harmful grip, it may swim away normally. The extent of these injuries remains to be discovered.
Keep these tips in mind the next time you reel in a trophy bass. The healthy fish that swims away lives to be caught another day.