Sea Trout (Salmo trutta)
Current record: 28lb 5oz 4dr
Water: Calshot Spit, River Test
Sea trout are the migratory, sea-run form of brown trout (Salmo trutta), the same species covered on our Brown Trout page, so what matters here is knowing what to look for and what rules apply, rather than the life cycle itself.
Fresh in from the sea, sea trout are bright silver with fine black spotting, easy to mistake for salmon at a glance. That changes fast once they're back in freshwater: colouring shifts to the typical brown trout pattern, olive on top with brown and black markings, tan to yellow underneath, as the fish gears up to spawn. Breeding males also develop a kype, a hooked upward projection on the lower jaw. After spawning, spent fish (kelts) heading back out to sea revert to silver again. Most run 35-60cm and 1-5lb, though bigger fish do turn up.
Sea trout fishing comes with real legal restrictions, and they vary by river, so check locally rather than assume. Close seasons typically run at least three months, and in some river systems (much of the Rhine and most German rivers, for instance) sea trout carry the same permanent legal protection as salmon. Estuaries commonly have a strict buffer zone, often 200 metres around the river mouth, where fishing is banned outright, and even where fishing's permitted, rules sometimes only allow silver fish to be kept, spawning-coloured (brown) fish must go back.
Fly fishing and spinning are the standard methods, and sea trout are prized for exactly the same acrobatic runs and fight that make salmon such a draw.