Sea-run trout are brown or rainbow trout that head down into salt water for a stint, then push back into the rivers. Aussie anglers rate them because they pull hard, smash lures in skinny water, and can be a real trophy fish in the right southern systems.
In Australia you mostly find them in Tasmania and a few cool southern mainland systems where trout rivers meet estuaries or the open coast. They work estuary mouths, lower rivers, tidal creeks, surf edges and rocky shorelines, usually in clean, cool water rather than warm dirty systems.
They hunt whitebait, smelt, small mullet, prawns and other little baitfish, and they will also grab soft plastics, minnows and flies that look the part. A lot of their feeding is ambush style around current lines, drop-offs and bait schools, with the better bite often happening at low light or when the water starts moving.
Tide matters most around estuary mouths and lower reaches, with the run-in and the first of the run-out usually giving them moving water and bait to pin against edges. Low light is a big plus, so dawn, dusk and overcast days often fish better than bright, flat conditions. Light to moderate wind can help by chopping up the surface and making fish less wary, but hard wind can dirty the water and make lure work painful. Smaller swell is generally easier to fish around river mouths and beaches, while a bit of surge can stir up food; once the swell gets heavy, the water can turn messy and shut things down.
A light 2–4 kg spin outfit with 6–10 lb braid and a fluorocarbon leader is a solid all-round setup, especially for small minnows, soft plastics and metal slices. If you are bait fishing, unweighted prawns, whitebait or small fish baits drifted naturally do well, and fly anglers do well with baitfish patterns in the lower river and mouth zones.
Some sea-run trout will travel between fresh and salt water multiple times, and they often grow much faster once they start feeding in the estuary or along the coast.