[NorthJerzyG]

I remember reading in In-fisherman it's better to lift them from the gill plate than grabbing them behind the head because you are removing less protective slime that way. As long as you only hold them vertically for a few seconds they are fine but the body weight, especially on larger fish, should be supported. Also, keep them, and other fish off the floor of a carpeted boat. That caused more fish fatalities during the study than other forms of mishandling.

Last, yes, their gills are fragile. However, gently sliding your hand into the gill plate and possibly brushing up against the gills won't damage them. It's damaged gills that kill the fish, not just slightly touching the gills..........