Fly fishing for grilse (one sea winter salmon)
- fast and furious

Fishing instructor, fly fishing tuition and fishing trips based in Scotland. Salmon and trout fishing advice, flies and articles.

Grilse fly fishing (article and pictures by Ally Gowans)


At the mention of grilse, the first picture that comes to mind is of sparklingly bright, energetic small salmon showing at the heads and tails of pools as they charge upstream the like torpedoes, hell bent on reaching every part of the river system. Those that are hooked usually do their utmost to struggle free with more vigor, energy and aerobatics than many a larger fish and for this reason they are highly prized as a sporting quarry.

What are grilse? Grilse are the first salmon of any generation of smolts to return as adults, having spent one winter at sea, growing from a few ounces to small adults of several pound's weight. They first appear at the end of May and continue to arrive throughout the remainder of the angling season.

Anglers usually think of grilse as the small fish arriving between May and July most of which are clearly identifiable and are largely unaware of their later brethren, several pounds heavier that are mistakenly classed as salmon. Knowing a little about the habits of grilse helps explain their reactions and to predict when are they more likely to be caught. Even in the lowest water some grilse are likely to enter rivers choosing their time carefully to minimise danger. Large tides, wind and darkness are all bear influence on their behaviour. Local knowledge is of tremendous benefit if you are trying to plan fishing at the best times and as always the chap who can pick and choose when to fish has a huge advantage over someone with a fixed let. Grilse are not likely to run very far up small rivers during low water unless there is a loch not far away. Large rivers, for example the Spey, Dee, Tay and Ness are different and lower beats can provide good sport during low water conditions because there are plenty of suitable lies even in those conditions.

Once they have committed themselves, grilse in large rivers move upstream with much less restraint than larger fish. Dusk unsettles them and gives them confidence, encouraging them to leave their daytime lies and go prospecting into faster, oxygenated water before trying to make progress during darkness. The most productive time to fish if the water is low is for a couple of hours before darkness and a couple of hours after first light.

Daylight migration takes place usually when rivers are above summer level but on the larger rivers grilse may push on if the weather is dull under any conditions. I have often heard tale of someone fishing a pool thoroughly for nothing, only to see the next angler step in and catch two or three grilse one after the other. Ah! You might say the first angler must have been doing something wrong. Not necessarily so say I, grilse can move through beats very quickly. Often it's not long after a shoal of fish is seen entering a pool that one is caught. Now is make your mind up time, having caught what you think is a running fish, do you continue fishing there or head for the next good taking spot upstream? It's a gamble. If the pool I'm fishing is a good one I normally give it another chance, should nothing happen I would have no hesitation in moving upstream to try to intercept the running fish again if possible.

Small rivers are a different kettle of fish. When they are low, virtually nothing goes far past the sea pools. Given a spate at the right time however it's a completely different matter and the river should fill with them.

Fly-fishing at grilse time produces something of a dilemma for the salmon angler. Do you fish "normal" salmon tackle or use "heavy" sea trout tackle? Much depends on the size of river you have to cover and what you expect to catch. Make no mistake, salmon and grilse are the same fish and fish of any size can be caught on tiny flies. On small rivers this is not too much of a problem. I am quite happy to fish with a #7 or #8 single-handed rod knowing that if a large fish gets hooked I can follow it and shouldn't run out of backing. Fish of 10lbs or even larger can be comfortably handled and even small grilse give a good account of themselves on such light tackle. Last season whilst casting to a grilse with a little tube fly I was amazed by the strength and power of the fish that I hooked. It turned out to be a fresh run summer salmon close to 20 lbs that handled relatively easily on my #8, 9ft 6ins rod.

On a large river, a single-handed rod might cope with a decent grilse that behaved itself but one that goes berserk or a large salmon will be a real problem taking either a ridiculously long time to land or ending in disaster. Using a 15ft rod and #10 line certainly copes with anything hooked, but it doesn't necessarily produce excitement with a small grilse attached. Best solution for typical medium sized rivers is I think, a rod of about 13ft for a #9 line. This gives good water command, enough "backbone" to handle a big fish and is perfectly suitable for grilse and summer salmon in any size of river. It will also cope with any size of fly likely to be needed and is long enough to handle a dropper if you wish to use one.

Fly sizes and types for grilse are identical to those for salmon but because rivers are often low and warm at grilse time smaller sizes are more likely to be used. I always like to make sure I have in my box a few small tubes' 1/4 & 1/2 inch long, armed with number 16 trebles and long shank doubles or trebles from 6's down to 12's or 14's. My favourite patterns are Ally's Shrimp, Silver Ally's, Cascade, Tummel Shrimp, Ally's Yellow Shrimp, Stoats Tail (preferably with jungle cock cheeks), Executioner, Pearl Stoat and Blue Charm. Those are my own tying, some of which differ a little from standard dressings and are included in the fly pages. The faithful Collie Dog is another must for when all else fails and for when you want to show them something completely different. It's surprising how often it works after all else has failed.

One final point about grilse, they are not the easiest fish to tail because their wrist is not strong and it compresses easily in the hand. One wriggle from a lively grilse and chances are that it will slip from your grasp. Beaching is always the safest method but if there are no beaches it is better to use a landing net. Like most anglers I hate carrying a landing net, but at grilse time it is foolhardy to go without. As a bonus the net is also handy for any sea trout you might encounter. In terms of salmon stocks, grilse are the most numerous components and therefore harvesting a few does little to dent the spawning effort. Here's hoping that this year's grilse runs are at least as good as last year's. Coming as they do during the peak holiday period grilse are the sporting highlight of the year for many anglers. And to conclude with some good news as I write in the middle of May the first grilse have already been encountered on the Tay, so it could be a good season. Tight lines and safe releases.

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Copyright 2007 Alastair Gowans AAPGAI and FFF Master and THCI, APGAI. All rights reserved.