i suspect you were fishing in the project area. maybe the person had his sunday shoes on and didn't want to come find you on the 1.2 miles of DLHA stream.
you are allowed to fish these waters agreed. some have concerns about the high water temps and trout. once temps get over a certain temp. (pa fish commision has a sight about this) mortality rate will increase if they are not handled properly during these conditions. looks like he was just giving you a heads up not knowing who you are or your abilities.
i see no harm and i wouldn't of been angry if someone left this on my vehicle during these hot days and water temps. i would have been targeting for the bass and perch in that creek and not the trout anyhow if it were me.
after reredaing the note and seeing he said "don't fish" i would say that is a little harsh.
an article i came across
I have seen several large trout in the last few weeks caught and released only to watch them float by me down river dead as a door nail. Below are five tips you can use to help trout survive the summer.
- Fish early or late in the day when the water is cooler. The warmer the water the tougher the time that the trout have to survive (also the less they feed). Once the water temps hit 68 degrees most trout that are caught will die from the stress.
- Fish heavier rods and tippets so that fish can be landed quickly (I personally use a 5wt). I know that it is fun to fish a 3 weight, but once you fight a nice trout for 10 minutes in 64 degree water, he is as dead as if you had taken him home with you, even if he swims off when you release him he will often die in the next couple of hours. If you have a large fish on and have fought him a while and see that it is going to take longer to land him, break him off so that he can live to fight another day.
- Spend as much time reviving the fish as you spent fighting the fish. Hold the fish in the current with his head in the moving the water until he swims off on his own. Do not release the fish in the slow stagnant water, there is little to no oxygen in the slow water in the summer time.
- Use barbless flies, not only do they come out of you better, but you do not have to struggle with the fish as long to get the hook out. If you are struggling to get the fly out, clip your line and release the fish, he will get rid of the fly.
- Avoid prolonged hero shots, we all want a picture with us with that trophy trout, but we all would like to see him swim off after the battle is done. So keep the fish in the moving water until the camera person is focused and ready, lift the fish quickly for one photo and then release it as described above.