@Rangervegas The more fish varieties a fishing spot offers, the lower your chance of catching a specific type.
If I were you, I'd go to a different spot where fewer fish can be caught.
Do you have Outdoor retreat?
As a test, I took a couple there, one with maxed fishing and the other zero fishing skill. They started fishing at the middle fishing spot on the eastern edge of the main camping ground.
The sim with L10 fishing caught a salmon after four sim-hours. The other sim caught a salmon 7.5 sim-hours later, soon after reaching Level 3 fishing.
They did not use bait, either.
Good luck with your catching your salmon.