Ive gone out on 6 guided trips in the last 3 months and personally caught or was in the boat with guys who caught 7 fish rom 4 ft,80lbs -8 ft,250 lbs....I know this doesn't make me an expert but from what Ive witnessed and done myself...the smaller fish,from 3 1/2 ft - 5 ft or so can be reeled in, grabbed by the tail while supporting the head, and lifted into the boat and then released by dropping head first in a smooth motion....pretty standard.....the bigger fish are reeled in and kept beside the boat and then brought to shore....they are almost always tired enough that I honestly don't think you need to tie the tail....I think it is a measure taken to ensure that the fish doesn't get away....I have tied the tail and the rope never went tight so I don't think it harms the fish but I don't think its needed....I went sturgeon fishing for the first time 3 months ago and I've been hooked ever since...there is nothing like leaning back with all your body weight against a fish that can make you fight with all the strength in your arms and body for 45 minutes +.....they jump, run, and dive like any fighting game fish......awesome!........they've been around for so long and it would be a shame if we were the species that destroyed them......conserve and protect...cheers