Especially when fishing where the banks are high, or it's impossible to get in the water, for instance if it's too deep. And even if you net a fish, you still don't have to lift it out of the water!
Some fish are extremely sensive to being handled - fresh salmon and sea trout, for instance, and even sea trout in the salt. Loose scales that rattle off even with the slightest touch decreases the trout's chances of survival after unhooking.
I carry a so-called "landing glove" made by Orvis. It's a great lille mesh glove that is easy to slip on, and it gives a great hold on the tail of a trout. But I only use if I'm certain I want to kill and keep the fish (which is rare, but happens). Generally, my rule of thumb is that if something gives you a better hold of fish, it's harmful to the fish. Check out this video of a char in a tank after it was handles with a woolen glove. I know a tank environment is different to a wild environment, but I think it's not necessarily more conducive to the growth of fungi. The video can be found here. There is no doubt that the mesh glove is less harmful, but - a better hold means harm to the slime layer - I'm fairly certain of that.
I've also gotten a new net that I'll be using in the pontoon boat and I think even in the rivers on high banks. It's a McLean (so great quality) and the gadget factor is high, since the net, with a push of a button, doubles in length. I think (I know) that'll come in handy with landing a big fish. There's no hassle unfolding the net - it just flips open and - ZAP - it's long. I love it! It'll be interesting to see hoe it holds up in the salt - maybe it needs a healty dose of WD40 or something similar in the spring mechanism before I take it out. The net's even rubber coated, so it should be as good to the fish as it can be.
Consider carrying a net if you don't already. Even if you want to keep the catch, the chances of landing it is much higher with a net.
Have a great weekend!