Rainbow Trout

Habitat Distribution

• Not native to the UK; introduced from North America and now widely stocked in stillwaters, reservoirs, and some rivers across England, Wales, and Scotland.
• Self-sustaining wild populations are uncommon — most UK rainbows are stocked fish — but feral fish do persist in a handful of rivers, particularly in the south and west.
• Prefer cold, well-oxygenated water; most at home in clear stillwaters, chalk streams, and fast-flowing rivers where water temperatures stay cool through summer.
• Stillwater fisheries — from small day-ticket lakes to large reservoirs — are the primary habitat anglers encounter them in across the UK.

Key Locations

• River Test, Hampshire — one of England's most celebrated chalk streams, with clear spring-fed water and a mix of stocked and wild fish.
• River Itchen, Hampshire — chalk stream known for gin-clear water and entirely wild trout on some beats; considered by many the benchmark for UK trout fishing.
• River Frome, Dorset — another southern chalk stream holding trout alongside grayling and salmon.
• River Usk, Wales — popular trout river flowing past the Brecon Beacons, with fish reported to 5 lb and excellent bank fishing.
• River Wharfe, Yorkshire — well-known northern trout river offering a different character to the southern chalk streams.

Specific Spots

• On stillwaters, fish patrol the margins and drop-offs early and late in the day; focus on the windward bank where surface food concentrates.
• In rivers, look for rainbows holding in the same lies as brown trout: behind boulders, at the tail of pools, and along current seams where food is delivered without much effort.
• On chalk streams like the Test and Itchen, fish hold tight to weed beds — ranunculus in particular — using the cover to intercept drifting invertebrates.
• In reservoirs, depth matters with season: fish ride the thermocline in summer, pushing shallower in cooler months when surface temperatures drop.