Nice shots 
Appologize for the bad quality of the following shots, very dark conditions with an old camera that could harly go over 400 ISO.
But maybe you can use some of these :
I did a few salmon shot back in 2008. I did not have any specific equipment and could not get one. So simply with housing, no adds.
I stayed just in the water (naked feet, was hard...) but with a small rock bridge behind me, allowing me to get some sort of camouflage.

and did manage to get a lot of shots. I'm a bit sad my camera (and skills/technique) was so bad back then, but I'd love to go back with better settings ! : )



Could even manage to get somehow close in a lake further up. It hurted.

Some are tired enough so you can get close.
For the other you either have to rush in dirty water, trying to get a shot,

or to get on the bottom and stop breathing for a few minutes. It is hard in such a cold water !

hope you can do more, it's so cool to have them close to where you live ! : )