Fly Fishing for Sea Run Brown Trout

Healthy Sea Run Brown Trout (Rick Wallace)

Every spring and autumn sea run trout enter large rivers and estuaries. My local rivers are blessed with sizeable runs of sea run brown trout. Every spring they chase baitfish into the estuaries and the lower pools of the rivers. In the fall they return for their spawning migration. These trout grow large and powerful on the plentiful prey of the lower river. There they have feasted upon various baitfish and even mud crabs. Trout are a generalist, they rarely turn down an easy meal.

The longer the Sea trout have been in the river, and the further they push upstream, the more closely they resemble resident fish. Their bright silver scales fade, turning to brown. Their baitfish heavy diet also start to adjust, They feed less upon fish and start feeding on the aquatic insect live.

Once in the river, smaller sea run trout often move around in age group shoals. One spring morning when I was working next to a river. I spied a large gathering of pan size sea run trout. They were holding mere yards from the bank. Maybe they recently entered the river, but they were not the smartest trout and not at all line shy. They hungrily grabbed at every streamer I presented, often several trout following at a time. In my 15 minute morning break, I landed five 10 inch long fish.

For the rest of the morning, I glanced back occasionally, and they had not moved on. They must of really liked that spot. The spot the sea runs were holding was just above the first riffle in the lower river. There baitfish shoals swim upstream, clinging to the shoreline where the current is at its slowest. I guess the sea run trout knew that so the shoal positioned itself to intercept any baitfish the moment they hit still water. I have never encountered such a gathering again.

Best locations to target sea runs

River Mouth

The river mouth or bar is a popular gathering spot for anglers. It is where many trout fishermen first head in the search of sea run trout. The mixing of salt and freshwater can see large numbers of fish gathering. Where there is bait fish, there are predatory fish like trout. I have spent hundreds of hours fishing river mouths. In that time I have caught only five sea trout during the day when casting out to sea. I rarely see others catching them. Most sea trout I see landed are caught on bait rather than a lure.

Fish the first riffle

I personally feel the mouth is best left for the Salmon fishermen. The most productive section of river for sea trout is surrounding the first riffle or rapid. The deep pool or gut which often forms at the bottom is a great spot for night fishing. Large sea trout hold at the bottom, try swinging a streamer close to the bottom.

While I feel the first riffle is the best, the riffles and rapids further upstream also provide good fishing. Especially in the fall when the Sea Run trout are migrating upstream. They can cover many miles in a given and are unlikely to stay in one spot for long.


Searun trout lay in wait near the riffles shore.

Sea run brown trout
Smaller Sea Trout often travel in shoals

In big rivers, the edge of the first riffle is a prime area to target sea trout. Where I fish, the rivers are wide and deep. Impossible to wade or cast across. In such places, I ignore the middle and concentrate on the sides. I look for likely holding places and lays close to shore.

In the lower sections of my home river, one side has public road access. A marshy riparian strip and farmland protects the other. The roadside trout see a lot of fishing pressure. So I paddle my fishing kayak to fish the far bank. That gives me a mile long section surrounding the first riffle which I have never seen another person fish. Both sea run and resident trout are common. They hold in a textbook like fashion, behind every submerged ,log, large rock or depression, trout often hold. They rest there, ready to ambush any fish moving pass. With the incoming tide, they often face downstream. Into the current, and they can intercept any bait swimming upriver. When the tide turns, so do the trout. They are now facing upstream, grabbing food from the current.

Fly fishing Rod for Sea Run Brown Trout

The weight of fly rod to use really depends on the size of trout you expect to catch, I personally fish a 6wt for most of my fishing. It has plenty of power and can easily handle trout over 10lbs. Even when fishing big water, I favour short accurate casts to where I think the trout are most likely to be holding. I do not attempt to cast across the whole river and fish blind, that is what spinning is for.

Brown trout, even powerful Sea Trout do not fight that hard. If you can keep them away from underwater obstacles you should be able to land them even with lighter gear. The stopping power of heavier gear is mostly required to keep them out of foul.


Terminal Fly Tackle for Sea run brown trout

I use a slightly heaver leader and tippet when fishing for sea run trout. Depending on what I have in my pocket, I typically fish with a 1X or 2X tippet. Sea trout are more forgiving of bad presentation and are less line shy than resident fish. I save money and use monofilament tippets; keeping the expensive fluorocarbons for sight fishing.

I also run with a shorter leader tippet combination, normally maxing out at around 9ft. The shorter leader makes casting a bit more forgiving.

Best streamers to catch sea run brown trout.

When fly-fishing for sea trout I prefer to use Streamers. I rate two above all others. I have caught sea run trout on in many rivers in both New Zealand, Canada and the west coast of the United States. These lures are the Grey Ghost and Rabbit (bunny) Fly.

I really like the Rabbit Fly tied to a size 2 hook. I like this streamer so much I have even written an entire article on it before. The motion through the water looks extremely lifelike to me. Based on the number of trout I have caught, the trout must think the same.

My other go to fly is the Grey Ghost. Most experienced fly fishermen probably know the pattern, apparently it was first tied in 1924 Maine. It was such a successful pattern that it is now widely used across the globe. To my eyes, the Grey Ghost does a good job representing the juvenile form of many baitfish. The Silicon Smelt streamer is another alternative, but I prefer the more natural Grey Ghost.

When low light fishing, I prefer the darker Rabbit Fly, or I will dig deep into my fly box and pull out a black woolly bugger.

As a general rule, I prefer to fish longer flies but still streamlined. I normally fish streamers tied on size 2 to 4 hooks.

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