Salmon behaviour in salt- and fresh-water is remarkably different. In saltwater salmon are actively searching out food and eating. In the period before moving into freshwater for spawning they gorge. That is why coho gain a pound a week as they move through the summer.
If you are miles offshore of, say, Ucluelet, in the summer, you can witness, on a calm day a true wonder of nature. All around the boat, for miles coho will be jumping from the water. In this crazy period, you can whack a flasher on the water beside the boat and a dozen coho will streak in to be the first to the possibility of food. I have seen them whack the flasher and refuse to let go.
While there is a difference between feeder and mature chinook bite and relation to structure, they are always found in a relation with structure. Not so the other species, which tend to swim as schools in a layer of water rather than chinook that tend to be found in the same spot, not because they school, but because they always have a relation with structure, and thus a ‘school’ is a composite of individual fish that are in the same area with identical behaviour.
While we associate daybreak in summer with the best bite, particularly for chinook, tide changes – before a high tide and after a low – also produce bites in the rest of the day. In that period before moving into fresh water, as bite reflex begins to wane, and because salmon tend not to feed at night, that is why daybreak produces the best bite. The salmon, chinook, having not eaten for many hours, are at their ‘hungriest’ first thing in the morning.
Chum are the real exception to other species, in their response to atmospheric pressure. The other four species tend to stop biting as the morning wears on, particularly on sunny days – meaning high pressure days. Chum bite index is highest on sunny days. Try Brown’s Bay on the flood in sun, for example.
Chinook behaviour changes as much as 100 miles from home with the eating reflex declining and them tending to move on shore and follow structure while the other species are found most predictably in tidelines that may be as much as ten miles off shore, for example, in Juan de Fuca Strait.
Chinook have the odd behavioural trait that they will inhabit surf line rock piles a long way from home and then migrate back into offshore waters to move south and east to home. Langara Island in Haida Gwaii, as we now call it, has several behavioural differences. Off Lacy Island on the west side, the chinook are coming on-shore for the first time and can be taken in 250 feet water in a middle layer, as in not structure related.
On Cohoe Point and Andrews on the east side, chinook may be taken a stone’s throw from shore on power-mooched cut plugs. Then, on the flood, a tide line forms off these two points at a 45 degree angle to land, and the chinook will move offshore and continuer migrating south. The same occurs off Vancouver Island. Kain’s Island in Quatsino is a surf line rock pile fishery, with the rat’s Nose, off Ucluelet, some 25 kms off shore, but structure nonetheless, and on the rocks at Wya.
Sooner or later, all salmon come to their estuaries, where behaviour changes again. Over successive tides, salmon are prepared for freshwater that they need time to adjust to breathe the oxygen in water that has very little ionic pressure, unlike the salt ocean they have been breathing in since smoltification some years ago.
When salmon begin to move into freshwater, their behaviour changes a great deal. From freely moving in the water column, they sink to the bottom and stay there. I call this committing to freshwater. In some estuaries, you can, at high tide be presented with the same species but with remarkably different behaviour. Those fish that come in with the tide are in the top layer, perhaps still eating, while those that committed on previous high tides are on the bottom in a school that is not moving, but waiting to move forward into a river proper. All time after that, you will be fishing on the bottom for schools that are essentially stationary in the day.
You will stand in the same place all day long, perfecting the drift with sink tips to find the best spot that produces the most number of bites. And abrupt low pressure can kill such fisheries. The other angle here is what I call managing a school. This works best with chum and chinook. With your casts above, around, on the far side of and below, and your movement around the school, you are aiming to place it in the best spot so that your fly/lure presents itself in front of the most noses in a drift and thus the greatest chance of getting a bite, from a group that only a few percent of will bite.
Most salmon, particularly chinook, spawn at night. Chum spawn in the highest water, whether day or night, and up to 90% of their eggs are wasted when the river level declines. Pinks spawn in the shallowest water, tailouts and riffles where water can barely cover their backs. That water has the highest oxygen level flowing through and around the gravel.
Coho are the real oddballs. Salmon, though no longer eating, still bite in freshwater for one of the following reasons: aggression, territorial, hormonal, passive and curiosity. Coho are the curious salmon and if fishing spinners you can watch a coho turn, aim at the spinner, follow it 25 feet or more, before whacking it. Chum, chinook and pink, are mostly passive biters; this means that if you run a lure or fly at mouth level through a school, typically 5,000 to 10,000 fish, a single fish mouths the offering and lets it go, which is why dink float setups work so well as the float dips under water and you strike before the fish lets go.
Chum, unlike the other species, have a phase, when they are moving in and up, of being snappy. Chinook and pink stop a fly; snappy chum, move to it, bite and turn their heads as the y move off. Coho do the same, though their chase is far more pronounced and they turn away from the lure the quickest and move the farthest, back to where they have been resting. And they rest in the softest part of the deep water. Find such water and you find the coho.
The curiosity bite of coho can be phenomenal on days when it rains two inches, the river rises several feet, and all anglers other than yourself, are watching NFL Sunday football games with Al Michaels and Chris Collinsworth. The bite is its highest on such days because coho are side-stream spawners and to get into those streams, the water level has to be high, to get in and to spawn. Thus their most active behaviour occurs in the greatest rain. Many seasonal streams only flow in the winter, and yet they can be high coho producers.
On my last trip fly fishing the North Island, I came across another type of behaviour for pinks I had not seen before. I was idly walking a channel several hundred yards off the main estuary on a falling tide. I happened to see some fish move by me, keeping to the shade – it was a sunny day.
After standing and watching for awhile, I realized that the fish were in saltwater but the tide was dropping and the riffle behind the fish became so shallow that the fish were trapped at the bottom end until the tide rose again. Below me, on what I discovered was a flat less than six inches deep, idle schools drifted about and bolted from time to time when a seagull flew over – salmon see the best straight up. (Incidentally, this means when you are trying to find the zone that being a bit above it is better than being below it. Of course, chinook have a behaviour that is an exception to this rule: they will follow a fly or shiny lure right to the bottom and pick it off the bottom, thus allowing you to strike and get the fish).
Because the fish were moving and changing directions, the chances of getting a fly in front of them was slim, and in shallow water the fly line just spooked them; however, above me, the small stream of salt and freshwater was too shallow for the fish to move up and thus they were indeed trapped.
After following them around for awhile, it came clear that they were spending most of their time in the shade of a large cedar that had branches within three feet of the water, and were in four to six feet of water. It was an awkward place to cast a fly as it required a sidearm cast. This was needed because in a regular ‘over the top’ cast, the fly, when it flips over, hit its highest point and comes to be tangled in low branches. With a flat trajectory, the pop up of the flat happens horizontally, and it went in under the branches and hit the water close to the bank.
Now the fun part. This was hunting at its best. The fish were in an intermediate step prior to committing to fresh water. I spent a couple of hours watching a fish turn, come toward the fly, and bite it. Some missed, and drifted away, which was a real groaner. Some missed and came back. Some returned several times. The hard part was not setting the hook when I could see the mouth close on the fly, and pull it right out of their mouths, but to wait to feel the strike and then set the hook.
Sometimes several fish chased the fly and only one got there. Sometimes it was a lazy follow that could be stimulated by increasing stripping speed. To a predator, a fleeing food object triggers that dash and bite behaviour. In other words this was hunting at its best and many fish were caught and released over the afternoon.
So, what does this mean? It suggests some fish in an intermediate step between salt- and fresh-water and thus, while appearing to be in a river, were actually in saltwater and still feeding, hence the chase and bite. The point was to decipher the attitude and find the spot in the pool where they were feeling safe and bity.
As this was fish in a barrel, I did not fish the spot again, but did go to check whether there were fish in this intermediate step prior to commitment. One day I came upon another angler trying his luck. He told me that was tired of peanut butter sandwiches and was going to catch one of the fish for supper. He was in the ankle-deep water, trying to lay a fly in front of a school.
I asked him if he knew the drill and he said yes. Part of the etiquette of fly fishing is not giving tips because the receiver may not appreciate them. So I said nothing and moseyed on. He remained shuffling about the shallow water. Later, I found out he did not catch anything. That was because he was trying in a circumstance with flighty fish, and needed to move up under the cedar where the much more relaxed fish milled around in the shade, ready to whack a fly.
The more you fish, the more you learn about fish, which is one of the prime things about fishing: there is always something new to learn.
Sorry for going on so long.