This is a problem that has worried surfcasters for many a year. Should you use a larger hook and miss a nice gurnard for example, or use a smaller hook and catch the gurnard and then risk the the odd immature fish?

I plumbed to hit the middle ground: I use a size 4/0, fine wire wide gape hook, I get these hooks from England, and it covers both sides of the coin. I hook and land larger fish, I fail to hook up with several of the smaller takes and don't have too many problems with small snapper.

There is an interesting video on YouTube from an angler on the south coast of England. In this video he shows how he unhooks fish he wishes to return. He uses forceps through the gill covers, out the mouth, and then he takes hold of the trace. he then pulls the trace line back through the gill cover and turn the hook around so the bend is facing forward and the shank is facing toward the tail of the fish. he then gives a gentle shake of the hook and it pulls back through the mouth easily without causing a bleed.

So simple, so easy, so effective and could easily be applied to undersized snapper.

Watch this clip and you will see exactly what I mean.

https://www.youtube.com/watch?v=rj0joS8pNR4