Avoiding trout when grayling fishing

Some timely advice on how to avoid catching out of season trout from WTT Volunteer, Kris Kent.

Kris works for Fishing Breaks, is a professional guide, an Advocate for Keep Fish Wet, a life member and long term supporter of the Wild Trout Trust.

I often get asked how to avoid catching out of season trout during the autumn and winter months, when fly fishing for grayling. Here are a few pointers:

On gin clear chalk steams you should be able to tell a trout from a grayling. Trout are darker with a square tail whilst grayling are pewter grey with a forked tail. 

Grayling are a shoal fish whereas wild trout tend to be more solitary. If you see fish in a shoal, they are likely to be grayling (or chub!)

Trout and grayling share the same habitat, but trout tend to prefer structure whereas grayling prefer uniformity. When fishing for grayling, concentrate on the more open gravely areas with uniform morphology and flows. Grayling will also hold in pool tails, slower and deeper water. Avoid the margins, pool heads, faster and shallower water and pocket water as this is where trout lie.

If fish are rising, grayling tend to leave a bubble in the rise form, although this is not always the case. Trout generally don’t leave a bubble.

Grayling have an underslung mouth designed for feeding on the bottom. In clear water they can often be seen grubbing about in the gravels with a puff of silt betraying them. Trout tend to feed higher in the water column. 

Fish deeper to target grayling – use heavier flies that get down to the grayling and avoid the trout. Heavy jig flies that are designed to bounce along on the bottom are very effective for grayling. If you aren’t catching the bottom once in a while you probably aren’t deep enough. If the fishery rules permit you to fish with multiple flies, pairing a heavy jig fly with a lighter /​smaller pattern presented on a dropper just above the riverbed is a great combination.

If you do find yourself catching trout, move on and try fresh water that better suits grayling and try heavier flies.

If you do catch out of season trout, return them immediately and don’t photograph them. 

If you are lucky enough to catch a grayling please treat it with respect, keep it wet, return it quickly and avoid the horrible grip ​‘n grin photos with the dorsal fin held up. There is lots of good advice on how to catch and release fish, including how to photograph them, on the Keep Fish Wet website or check out the Catch and Release page on this website.

Finally, if you are wading the river in pursuit of grayling remember that trout and salmon may be spawning. Never wade close to or through spawning redds, if in doubt get out or move on. Check out this blog post by WTT Conservation Officer Gareth Pedley for more information on how to spot redds.