Releasing fish with Baratrauma

[hammer4reel]

Originally Posted by bulletbob

Maybe someone can answer a question for me on this topic.. I too have seen way too many dying fish float away, feebly trying to right themselves after being cranked up from deep water.. Any device that cuts this down a lot is worthwhile.. However, I don't see this problem near as much in freshwater .. We catch lake trout while jigging as deep as 200 FOW, and the fish always swim back strong.. I have even caught perch and sunfish at 85 FOW in summer and they swam back strong... Hadn't really thought about why that may be, but this thread got me thinking about it... Even at 75 feet I have seen a lot of salt water fish go belly up on the surface unable to swim back down, but never saw it as yet in a fresh water fish caught from deep water.. Anyone know?... bob

FROM GOOGLE


Freshwater fish can experience barotrauma, especially when rapidly brought up from deep depths, but some species are less susceptible due to a physiological adaptation called a pneumatic duct which allows them to release gas from their swim bladder, effectively "burping" to adjust to pressure changes; fish lacking this duct are more prone to barotrauma when brought to the surface quickly.
Key points about freshwater fish and barotrauma:
Swim bladder function:
The swim bladder, a gas-filled organ that helps fish maintain buoyancy, is key to understanding barotrauma.
Physostomous vs. Physoclistous fish:
Fish with a pneumatic duct connecting their swim bladder to their digestive tract (physostomous) can release gas more easily and are less likely to experience barotrauma compared to fish without this duct (physoclistous).
Examples:
Fish less likely to experience barotrauma:
Trout, salmon, and pike have a pneumatic duct and can adjust their swim bladder pressure readily.
Fish more likely to experience barotrauma:
Walleye, perch, and bass lack the pneumatic duct and are more susceptible to barotrauma when brought up from deep water