Crappie in Shock

[Atimm693]

Since I started fishing a different lake I've noticed something strange with the Crappie that I've caught.

Probably 90% of the time that I catch and release a fish from this lake, I toss them back in the water and they just float on the surface with their mouth open, like they're in shock.

I have to grab and swim them around a little, sometimes push them down a foot or so and they'll swim off.

Today I even had one come unbuttoned near the boat, he went into shock and floated right to the surface.

Is it something to do with their swim bladder? The fish aren't that deep, 15-20 feet down in 50 fow.

None have been gill hooked or otherwise hurt.

I do not play the fish that much, have to horse them out fairly quick so they don't wrap me up in tree limbs.

It's got me a little bit puzzled, I have caught fish from similar depths before (although the water wasn't as cold) and not had them act like this.