This is for the tournament fishermen who wonder, “Why are my fish floating in my livewell, and why do they eventually die?”
When fishing in deep water, 20 feet or more, there is a change in water pressure that affects the swim bladder in caught fish. The decrease in pressure over-inflates the swim bladder, keeping the fish from being able to stay in an upright position and underwater. This causes a lot of stress and fatigue to fish as they use more oxygen in livewells and can build up high levels of lactic acid in their body, which will eventually lead to death.
Any time I see a fish that is not under the surface of the water, it is time to vent the fish swim bladder. To do this, I use the Ventafish Tool. It is a tool that encases a hypodermic needle that is connected to a spring for ease of use and safety.
To start, I will lay the bass flat with my left hand flat over its gill plate and my thumb on its belly. Then, with my right hand, I flatten the pectoral fin so it lays underneath the lateral line and aim off the point of the fin 2 or 3 scales back. I then insert the needle underneath the scale and through the skin at a 45-degree angle and move the needle to 90 degrees while still in the fish on push down until I hear a slight hissing sound. You can also do this while holding the fish underwater and see the bubbles coming out of the fish.
As for how long to vent a fish, it depends on the size of the fish and how deep the water is that it was caught from, but for a general rule of thumb, I give a fish one second of venting per pound of the fish weight.
A few words of caution: 1.) Fish like to flop and a small needle can easily be knocked into you 2.) when venting a fish under water, be careful not to let water into the swim bladder and 3.) a dull needle tends to cut a hole instead of a small incision, which can lead to over-venting or letting water into the swim bladder.
It is best to practice venting fish while out on the water before you are fishing a tournament.
I suggest to vent keeper-size fish and keep them in your livewell for the day to help build confidence in the procedure. In many smaller club or fruit jar tournaments, there are many fish left floating around the weigh-in site; this is a great opportunity to practice venting fish and help these doomed fish survive.
As for the claims that venting fish will kill your fish, I have vented fish in my pond several times and have caught these fish months after the process. If you are still wary of venting fish during your tournament, do it after you weigh your catch and give those fish a chance at surviving.
Written by Dustin Evans