Brown trout (Salmo trutta) are native to Europe and were first introduced into New
Zealand in the late 1860s from British stock that was first established in Tasmania.
Many subsequent introductions have occurred, and brown trout are now the most widespread
and common introduced fish in New Zealand waters.
Brown trout are primarily a freshwater species, but can spend time in the sea. One
specimen that was tagged near Christchurch was later recaptured in the Mataura River,
while another tagged in the Wanganui River system turned up in Taranaki 125 days
later. Spawning, which occurs in autumn and early winter, takes place in fresh water.
Brown trout do not undertake extensive spawning migrations like some of the other
salmonids, but some movement does occur, particularly for lake populations. Like
all salmonids, the female digs a redd where the eggs are deposited.
Although the brown trout fishery does not receive as much publicity as that for rainbow
trout, these fish are highly prized by anglers because they are considered much harder
to catch. Specimens up to 14 kg in weight have been recorded in recent times, but
a fish over 5 kg would cause any angler to smile.