The autumn run is what a lot of salmon and sea trout anglers wait all year for. On plenty of British rivers the back end brings the biggest push of fish of the season, and there is a particular atmosphere to it, short days, coloured water and the sense that this is the last chance until spring.
Rain moves fish, and that is the whole thing
Salmon and sea trout run on water. Fish stack up in the lower river and in the estuary waiting for enough flow to move, and when the rain comes they go.
That makes autumn fishing entirely dependent on the weather in a way that other fishing is not. You can have three weeks of nothing and then a week where the river is full of fish. Watching the gauges and being able to go at short notice matters more than any tactical decision you will make.
The classic timing is not the peak of the spate, when the river is high and dirty and the fish are running hard. It is as the water starts to drop and clear, when the fish settle into pools and become catchable.
Where fish sit in autumn water
In higher water, fish take the easiest line upstream, which is often much closer to the bank than in summer. The main flow is too strong and they avoid it.
Look for the softer water at the edges, the tails of pools, and anywhere the current is broken by a rock or a change in the bed. In a big flow, fish hold in places that would be too shallow and too slow to interest them in low summer water.
As the river drops, they move back into the classic holding lies in the necks and bodies of the pools.
Flies and how to fish them
Autumn generally means bigger and darker than summer. Higher, coloured water calls for a fly the fish can find, so tube flies and larger dressed patterns come into their own.
Sinking tips or full sinking lines get the fly down through the extra flow. In summer you might fish a floating line and a small fly just under the surface, but in an autumn spate that fly will never be seen.
The traditional down and across swing still catches most fish. Cast, mend to control the speed, let it swing, take a step down. The discipline is in covering the pool methodically rather than in exotic fly choice.
Sea trout are a night game, mostly
Sea trout behave differently. In clear low water they are almost entirely nocturnal and fishing for them means fishing from dusk into the night. In the coloured water of an autumn spate they will take during the day, which makes autumn one of the more accessible times to catch them.
If you do fish at night, know the pool in daylight first. Walk it, note the snags and the wading, and set up before dark. Night fishing an unfamiliar pool is how people get into trouble.
The conservation question is real
Salmon stocks in many British and Irish rivers are in serious decline, and autumn fish are the ones that will spawn in a matter of weeks. This is not an abstract concern.
Most rivers now operate mandatory catch and release for part or all of the season, and many operate it entirely in autumn. Know the rules for your river before you go, and beyond the rules, treat every fish as if it matters, because it does.
Barbless or debarbed hooks, keep the fish in the water, no lifting for photographs where the rules or good sense say otherwise, and give the fish proper time to recover before release. A coloured autumn cock fish is close to spawning and deserves to get there.
Being realistic
Salmon fishing involves a lot of blanks and autumn is no different. What autumn gives you is more fish in the river and better odds when conditions line up. Be ready to go when the rain comes, fish methodically, and take the view that the days you blank are still days on a river in autumn, which is not a bad way to spend your time.
Sarah Marsh came to fly fishing through her father, who kept a rod on a small syndicate water in Devon. She spent her teens fishing stocked reservoirs and gradually worked her way toward wild fish on moving water – first on rain-fed freestone rivers in Wales, then on the Hampshire chalk streams she now considers home water.
She holds a level 2 APGAI fly casting qualification and guides informally on the River Test and, from June to September, on a private beat on the River Tay for Atlantic salmon. Her personal best brown trout came from the Itchen at 4lb 1oz; she’d sooner not talk about the salmon that came off at the net last August.
At The River Bend, Sarah writes the game fish species guides, fly fishing technique articles, and the legal content covering trout and salmon regulations.
Covers: Brown trout, rainbow trout, sea trout, Atlantic salmon, fly fishing, chalk streams, Scottish rivers, close season and regulation articles