Can I safely release a lake trout caught from deep water?
Usually yes — and this is a genuine anatomical gift. Lake trout are physostomous: the swim bladder connects to the esophagus by a duct, so a laker hauled up from 25 m (80 ft) can burp expanding gas out through its mouth instead of ballooning the way a physoclistous fish like a walleye does. The honest caveats: the fish must actually vent, so bring it up steadily rather than winching it; deep summer fish crossing into warm surface water take thermal stress on top of pressure change; and some fish fail to vent fully and float. Never puncture ("fizz") a lake trout — help a floater upright, move water over its gills, and let it burp and sound.
The full story
This answer is one piece of a longer lesson — setups, diagrams and the reasoning behind it.
More questions about Swim bladder & pressure
Same topic, other species
- How can crappie hover motionless in mid-water for hours? — Crappie
- Can a muskie caught deep be released safely? — Muskellunge (Muskie)
- Why do perch pulled from deep water come up bloated? — Yellow Perch
- How does a pike hover dead-still, then explode? — Northern Pike
- What happens to a walleye pulled up from deep water? — Walleye