Fish handling and welfare is something I have become more accustomed to practice,
Everyone has their way but maybe the principles are the same.
So for bass ect , never drag them up the beach or hold by the snood with them dangling, always land them and pick them up by the tail and under the front fins, thumb in the mouth is ok if your holding the tail, but never suspend them with all the weight on their jaws, some bass anglers have a thumb in the mouth while taking a photo, horizontal , this can damage the spine when the body is bending down more than 30 degrees,
never put you fingers inside the Gill plate, that can cause damage to the gills and dease, wet you hands, the less scales lost and slim removed the better. Coz the scales and slim protect the fish not only from dease but the salt water will burn their skin if it was removed
Hounds and Ray's here is a picture which explains.
Small fish whiting and pout ect, there are many ideas why they don't swim off well after release, one is thermo shock, so I always have my t bar with me, and release them over the water, and not touching them.
If the water is rough then a bucket of sea water will do, but change regular as the fish recovering will be depleting the oxygen levels in the water.
I see so much bad handling in picture , hounds and Ray's especially , I have seen pictures of 14 lb hounds held by the back of the head to to get a selfie. They don have a rib cage to support the organs and dangling them will damage them, they swim off ok but can die later. Also never hold or drag by the tail? This can damage the spine
Remember that if your having trouble unhooking , forfeit the photo, the fish had just done a marathon and fought for its life and is very short of oxygen , so soon you get it back to the water the better, normally I like to get them in under a minute , but some say less at 40 second s
In some in well known mags, the pictures are bad and would have thought that they would have edited it, so that people can se how to handle fish, but there is not enough info on the subject.
Hope that help and sure other will add to it .
Tight lines mate