I picked up a couple of dozen flies yesterday and while looking through the guy's assortment, this came to mind.
Salmon flies look nothing like any bugs around here. Matter of fact, it's my understanding (and I "DO" stand to be corrected) that salmon don't feed while in the rivers. It's also my understanding that the fish will only strike at a fly because it's annoying to the salmon.
So, if my 2 points of understanding are correct, why is it commonly stated that a certain fly is good in one river while people swear by a different fly on another river. I don't believe it has anything to do with the person fishing because I've heard accomplished fishermen (both genders included here) say a certain Cossaboom works well on one river while nothing but a White Lightning will work on the river a few miles away.
Your first point of understanding is correct, i.e., atlantic salmon don't feed when returning to the river to spawn. Your second point of understanding is as good a guess as anyone's. There are as many theories as to why atlantics strike a fly at this time as, I think, there are fisherman.
Regarding fly color: the Miramichi, for example, is considered a "green" fly river. Of course, other colors work too. There's quite a difference between the flies fished on the Gaspe' rivers and those fished on the Miramichi system.
Tradition probably has as much to do with it all as anything. For the last couple years, it looks like the white-tailed green machine is THE fly for the Miramichi. Why? Well, one pretty good answer is that everyone is fishing it. If its the fly that's in the water, its gonna be the one that hooks the fish.
Gary is much more current than I on Atlantic fishing. With pacific salmon the closer you are to the salt and the fresher the fish to the river both present the best chance for a good solid grab with little hesitation. I can only theorize that when they first hit the fresh water the instinct to grab a fast moving prey item is stronger than when they have been in the rivers for weeks on end.
Here when fish are fresh they respond to a fast moving fly and I can only guess at why this is. As for color, now you are into no-man's land. The arguments and opinions regarding color vary in as great of numbers as do salmon fly patterns. We call them flies because they are materials bound to a hook with silk or nylon thread. That's about as close as they get to being "flies". As long as you never stoop to using those plastic beads that look like fish eggs I guess whatever you put on a hook can be called a fly
I know that a lot of theories from Atlantic salmon fishing applies to steelhead fishing, but I really know nothing about Atlantic salmon.
But, based on my experience with steelhead, it has more to do with day to day conditions, but some rivers around here are known for specific colors or flies. The Sandy river has fish that like large flies in general, whereas on the Clackamas, smaller marabou flies can be more effective. But, if Atlantics are anything like steelhead, I do know that they'll hit just about anything if presented properly (i.e. right in their face). I know someone who has caught a summer steelhead with a chips-ahoy fished on the surface (though he wasn't a fly fisherman, lol).
This is the billion dollar question here. Ill throw in my two cents but it might turn into a nickel's worth.
I cant speak for Atlantic salmon, or even the nuances of salmon fishing in the lower 48. Ill only base my post on things I have experienced personally or have seen with my eyes. I have read a bunch of things that have and have not worked.
All of the salmon fishing I have done have been with streamers. Being adaptable to the conditions, location, and target species are key to it all. Some places in AK somewhat handcuff the fisherman with fly regulation such as the Russian River that does not allow weighted flies and a small gap limit 3/8" if I am not mistaken. Otherwise it is nearly universal that the patterns I tie are weighted, with bigger gapped hooks with flash.
In my experience there is less variablitity between watershed patterns that work as there are commonality between target species. Meaning a pattern I tie for one species will often work on most watersheds but will not work for another species in the same watershed. Ill give a breakdown and some theories per species below.
I think there are a few different reasons that salmon will bite a fly or any lure in freshwater when in theory they are not feeding.
Natural instinct to attack salt water prey: This is why kings/silvers and pinks can be caught on flashy baitfish patterns. Using a wounded type retrieve helps in this. As Ard mentioned, there is still that instinct especially in fresh chrome fish.
Annoyance: This is especially true when a fly is bonked off a fish's head or nose. Common in thick schools of fish and especially among reds. Ill talk about flossing below...
Bed/Redd/Roe protection: I have a theory that salmon are protective of roe, even if it is not thier own. This is why it is common and very effective to catch salmon using roe as bait. The theory being that they are holding the eggs in thier mouth to be buried in the nearest bed. I have caught many a silver on an egg sucking leech because I think they are attempting to attack something that is feeding on roe.
Flossing: This is especially true for red salmon when they are upstream in transit to the spawning grounds. They are packed in schools and migrating quickly. They are maddeningly focused only on the migration so it boils down to the skill of the fisherman to floss that fly through the mouth of fish. Then strip the hook through, and it is not a true strike, but also not simply snagging either.
So a breakdown on my experience on what works for each of the big four species. As much as I love eating chum/dog salmon they arent easily found in a fly fishing spot I only know of a few places and those are out in Bristol Bay of western Alaska fame. The tactics used for silvers and reds will hold true though.
King/Chinook: I use a bigger hook from 2/0 to 2. I have found that green/chartreuse work well. It seems that either big gawdy maribou and bunny strip flies work well with flash. A stinger hook helps where it is allowed by regulation. Flash, but not to much helps a bunch. Also pink is a secondary for a base color. But do not overlook blue and or purple with some yellow built in. If you can get something that vibrates it helps.
Silver/Coho: Pink is everything, others just help. Flash is also important. I am generally using some sort of pink baitfish imitation with lots of flash. Green ESLs in big sizes work well also.
Pinks/Humpies: size 2-6 and nearly anything dragged in front. They are small salmon but very aggressive. Known to chase and bite a piece of yarn on a hook. I like using a basic esatz wrapped shank and marabou tail on a size 4 hook. Pink and green work best.
Reds/Sockeye: This is the most challenging. At sea they are fairly omnivorous. They feed on some krill and shrimp but also a lot of algae. Which is why I think they are the best tasting. So the baitfish imitations that work so well for other salmon are more or less not applicable here. This is where you get into annoyance/aggressive strikes but also flossing. I have been lucky and priveleged enough to fish the massive and incomprehensible until you have seen them Bristol Bay salmon runs. That number in the hundreds of thousands per day. The migration is nothing short of a magical gift of nature and unfortunately has been wiped out in most other places by humans. There are threats of this now with Pebble Mine but there are other threads to that. Also keep in mind that the famous footage you see of big brown bears catching leaping salmon from
falls, that these are sockeye salmon.
Personally I think sparsely tied flies, like Mickey Finns, Blondes, and the standard Coho flies are good. Where allowable add lead wire to the shank. I think that orange works well, as does red. Secondary to that will be the greeen/chartruese then purple and any lighter contrast color is killer. In my opinion, it helps most when enough color and flash is added that the fisher can see the fly and direct it to right in front of the fish to entice strike or pull the fly through the mouth.
I am sure that anyone reading this will have all sort of objections or other ideas and so be it, but this is what has worked for me and I am not ashamed of the success I have had with exactly what is described above.
No objections here Bud, that was a well thought out and thorough reply. How bout them Kings, did you find any?
Not yet, hitting the Deshka this weekend. I was down at Ship on saturday and snapped my 10wt when I was double hauling and caught my fly on one of the utility pole guy wires. Shipped it back for warranty replacement. Good thing I have a backup.
Deshka numbers are picking up and I know some folks who have landed decent fish. I will let you know how it goes.