Hi Lief and welcome to the Speypages
That is probably the best first question I have ever seen here on the Speypages !! Talk about owning up and being responsible, BRAVO !!
I don't think there is just one thread here describing river etiquette, there are many. If you do a "etiquette" search here, probably in the General Forum, you will see many threads come up. Ranging between "low holing" to "boat etiquette".
Same thing for fish handling, many threads will be found in the search function
My personal thoughts:
1. When approaching the river, look around before you step in. Another angler can be bankside re-rigging and planning to step back in. Crowding or low-holing is not cool.
2. I personally believe all rivers should be rotating, meaning all anglers start at the top of the run or pool and cast and step their way down through at a pace that allows for a cast and a swing to be made. No concrete shoes here !! This allows for the next angler in line to have room to step in and start his/her run through. Everybody gets to fish a run/pool this way
3. Treat other anglers with respect and dignity. In other words, treat someone as you would like to be treated.
4. Respect the environment and all it's inhabitants. We are guests in their home !!
5. Pinch your barbs. Safety for both you and the fish.
6. Keep all fish wet, focusing on the gills. Dry gills kill fish. Frozen gills kill fish. It would be like us running a marathon and then someone sticking your head underwater as you try to gasp for air.
7. Handle fish with the utmost care. Land fish in the water, do not beach fish. Sand in their gills will scar the organ and cause long term breathing issues for the fish. Landing fish in the water will protect them from bouncing on rocks. Rocks hurt fish, period. Use a net if you are alone or cannot control the fish when it is in close.
8. Share your whiskey with fellow river brothers and sisters
9. Do not let an illegal act go un-reported. Do not confront the individuals, just take note of details like license plates, boat registration numbers, time of day, description of individuals, etc.
10. Do not prolong the battle between you and the fish, be aggressive and exert appropriate pressure during the battle. Use tackle that is appropriate for the fish you are fishing for. Going to the river under-gunned is disrespectful to the fish. They deserve to be landed as quickly as possible to increase their chances for survival.
The above is my opinion. There are more thoughts and add-ons if you do a search
Again, welcome to the Speypages and enjoy your time here