That’s what I do, at least.
I have no problem angling. In fact, in a couple days I’m getting my first fishing license in over 4 years. So I’m going to happy to finally post some fish picture. IF I catch them. ;)
Anyhow, I think angling is a great idea because I’ve been a big fisher all my life, I just hardly photographed anything I caught. I also believe that fish are undoubtingly the most understudied and under observed vertebrae Class and I will full-hearted support any who have photos.
Angling is really the only practical way of observing many types of fish. Anyone can do it with a little effort, it is relatively inexpensive, and it is legal. I live in one of the US plains states and the iNat observations for fish are woefully lacking. Swimming with a waterproof camera is not always an option, fish seen from above are usually unidentifiable to the species level, and trying to catch a fish with a dip net from the shore is almost impossible.
Even though angling for observation will cause some fish death, most of the fish in my state that can be caught with a hook and line are either stocked by the government, invasive, or very fecund and therefore the loss of a few is unlikely to have any environmental impact. I would imagine the situation is similar in many other lakes and streams in the US, and probably elsewhere.
One more thing that no one has mentioned yet is that “trophy pictures”–observation photos showing a triumphant angler with his catch–should probably be avoided on iNat. I come across them semi-frequently and they give the impression that the only reason the observation was submitted was for the vanity of the angler. In reality, any fish observation, whether it is a world record or just fry, is useful data for iNaturalist. If I can offer my opinion, I think that a simple photo that clearly shows some distinguishing marks of the fish–whether in-hand, in a net, or some other position–is all that is needed.