One of the most common ethical dilemmas faced by walleye anglers is deep water fishing. Barotrauma, or internal damage done to a fish when pulled from deep water, is a very real situation that walleye anglers face across the Midwest. Fortunately, with some considerations, walleye anglers can be comfortable knowing they are making ethical decisions with their fishing methods and locations.
What is Barotrauma and When Does it Occur?
Barotrauma is when a pressure change is so rapid for a fish that internal organs, most commonly it’s swimbladder, will burst and expand due to the rapid change. This occurs when walleye are caught in deep water, and reeled to the surface and landed quickly.
Barotrauma begins to occur around 26 feet deep, but is most commonly seen in depths greater than 30 feet. While there is no set number or threshold, a good rule of thumb is the deeper the water the fish is caught, the more likely the fish is going to experience barotrauma.
How quickly a fish comes to the surface, angling technique, water temperature, and where the fish had been previously are also important factors to consider as well. For example, a fish that has been foraging in shallower water and has just moved into deeper water is less likely to experience barotrauma. A large fish that was hooked jigging, and put up considerable fight before reaching the surface also is less likely to experience barotrauma than a smaller fish that was reeled in quickly.
Again, there are no hard and fast rules when it comes to barotrauma. Every fish, and situation, is unique. This is why anglers need to consider barotrauma in their location and technique as a whole, and make ethical decisions from there.
How Do You Know When Barotrauma Has Occurred?
Fish that have experienced barotrauma will have several tell-tale signs. The most obvious sign is an exploded swimbladder, or a swimbladder and/or stomach that is visibly protruding from the fish’s gullet or throat. This is the most common sign of barotrauma.
Bulging eyeballs is another classic sign of barotrauma, as organs other than the swimbladder will also experience significant pressure changes and in turn physiological changes. This is important to consider, because this means fish may suffer serious internal damage in a number of key organs when barotrauma occurs.
How Do You Know a Fish Will Die of Barotrauma?
Depending on the severity of the barotrauma, the mortality may or may not be immediately apparent.
Fish that have experienced severe barotrauma will likely be dead, or very near dead, as soon as they enter the boat. In the same breath, these fish will likely not be able to swim away should they attempt to be released and will likely float next to the boat if a release attempt occurs.
While this is an obvious sign of mortality, just because a fish swims away doesn’t mean that it’s in the clear and going to survive. As discussed above, the extent of the impact of barotrauma may not be immediately apparent. Internal organs may have expanded and been damaged, the stress of a fight, especially in warm water, may cause delayed mortality, and other impacts not visible may lead to complications that lead to mortality in the coming hours or even days.
When Should Barotrauma Be Considered?
Barotrauma should be considered any time there is, or may be a desire, to catch and release fish.
Anglers that are looking to catch fish to keep and eat need to be less concerned about barotrauma. If the goal is to catch a limit of harvestable sized fish, then those fish are going to be harvested whether they are from shallow water and in reasonable condition or from deep water and unreleasable.
After a limit of fish is obtained, if anglers are targeting trophy caliber fish, or anglers simply want to practice catch and release is when barotrauma needs to be considered more seriously.
What is the Best Way to Avoid Barotrauma?
The best way to minimize the risk of barotrauma is to target fish in less than 30 feet of water.
For anglers using forward facing sonar, or other live imaging, this means casting to and working marks that are in less than 30 feet.
For anglers trolling crankbaits with leadcore or other line counting abilities, this means setting your baits to run in depths less than 30 feet.
For anglers bottom bouncing, jigging, or other bottom oriented presentations focusing on fishing in less than 30 feet of water.
What Matters More – Water Depth or Where a Fish is Suspended?
What matters the most is where the individual fish is in the water column, not the depth of the water as a whole.
Advancements in sonar, including but not limited to forward facing sonar, have given anglers a perspective that walleyes are not the bottom oriented fish they were perceived to be. While yes, walleyes will associate near the bottom, walleyes will also commonly be suspended as well.
This means that walleyes may suspend in relatively shallow depths over very deep depths of water. It is not unrealistic to see walleyes suspended 10, 15, or 20 feet down in water depths greater than 50 feet.
Where the individual fish is in the column is, at least in most cases, what the fish is going to be accustomed to. Could a fish in deep water race up to chase a bait higher in the column and experience barotrauma? Yes. However, the most likely factor is that the higher the fish is in the water, the more likely it is to be feeding and chasing forage and in turn baits.
What’s the Best Way to Avoid Barotrauma When Walleye Fishing?
This all leads to our most important question – how do we do our best to make ethical decisions and avoid barotrauma when targeting deep water walleyes.
The best approach is to focus on fish that are less than 30 feet deep, however you choose to fish them. By targeting fish in depths less than 30 feet, you’re more likely to be able to release your fish safely than not.
The next step is paying attention to signs of barotrauma. If your fish look healthy, are kicking off well, and not floating back to the surface you’re probably doing just fine.
If you’re seeing fish floating after you release them, are having a hard time getting them to kick off, or seeing signs of protruding when checking their gullets you may need to target shallower fish.
The fact of the matter is that mortality is going to occur in fishing. When done legally, harvest mortality is an important part of fisheries management and no angler should feel bad about keeping fish for a meal when following legal guidelines and regulations.
Deep hooks, injuries that occur in the process of landing or handling a fish, or other noncontrollable factors are also going to occur. It’s just the nature of fishing.
By targeting fish in less than 30 feet, properly handling them to the best of your abilities, and ensuring a quick and safe release is the best we can do for practicing successful catch and release.
Being mindful of all of these factors is a key part of being an ethical angler, and ensuring the sport of fishing for generations to come!
