Lake Independence Citizens Association

If you’ve been fishing for crappie in the deeper holes of Lake Independence, you may have seen a fish struggle to dive back down after being released. This isn’t just exhaustion — it’s often a physical condition called barotrauma.

 

What Is Barotrauma?

Think of it as “the bends” for fish. Crappies have a physoclistous swim bladder, meaning it is not connected to their throat. They can’t simply “burp” out excess air.

 

When a crappie is brought rapidly up from depths of roughly 20–30 feet or more, the drop in water pressure causes gases in the swim bladder to expand. Because the fish cannot release that gas quickly enough, the expansion can interfere with its ability to swim and maintain depth.  

 

Signs to Watch For

A fish suffering from barotrauma may show:

• The Float – The fish remains at the surface and cannot submerge.

• Distended Abdomen – The belly appears hard or bloated.

• Stomach Protrusion – In severe cases, the stomach can be pushed out through the mouth.

• Bulging Eyes – Occasionally seen in more extreme cases.  

 

Why It Matters for Lake Independence

Even if a fish initially swims away, internal stress or injury from expanded gases can lead to delayed mortality, especially when fish are caught and released repeatedly from deep water.  

 

During winter and in the heat of summer, crappies often school in deeper water. High catch-and-release activity in those depths may unintentionally increase post-release mortality if barotrauma is not considered.

 

How You Can Help

Be Depth-Aware

If you’re fishing deeper than about 25 feet, recognize that the risk of barotrauma increases. Consider keeping fish within legal limits rather than repeatedly catching and releasing fish from deep water.

 

Limit Sorting

Avoid high-volume catch-and-release or “sorting” in deeper water, as multiple pressure changes increase stress and mortality risk.

 

Reel Steadily (But Realistically)

Bringing a fish up steadily — not rapidly — may reduce stress, but it does not eliminate barotrauma risk.  

 

Use a Descending Device

If releasing a fish caught from deeper water, a weighted descending device can return it quickly to depth. The increased pressure recompresses the gases and significantly improves survival odds. (You can find many practical demonstration videos below.)  

 

Skip Improper “Fizzing”

Poking needles into fish to vent gas should only be done by experienced anglers using proper tools. Improper technique can cause infection, organ damage, and increased mortality.  

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Recommended Videos

• MN DNR Crappie Barotrauma Study (Deep Dive): Watch on YouTube
  A fascinating look at the MN DNR's research into how Lake Independence-style crappies react to being pulled from the depths.

• How to Use a Fish Descender Tool: Watch on YouTube
  A quick, practical demonstration of how to rig and use a descending device to get fish back to the bottom safely.

• Understanding the "Bends" in Fish: Watch on YouTube
  A great visual explanation of the science behind why this happens to panfish.

 

Further Reading

• MN DNR Official Barotrauma Page: Visit Website
  Comprehensive details on the biology of barotrauma and state regulations.

• Catch and Release Best Practices (MN DNR): Visit Website
  General tips for keeping the Lake Independence fishery healthy.

 

The Bottom Line

To keep Lake Independence a premier crappie destination, we need to be mindful of the physics happening beneath the surface. If they’re coming from deep water, consider keeping your legal limit and calling it a day.

 

Responsible anglers help protect the fishery for everyone.

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