Sea trout

Sea Trout

Scientific name: Salmo trutta (Linnaeus, 1758)
Family: Salmonidae
Order: Salmoniformes
Class: Actinopterygii
Irish name: Breac Geal
Irish record angling fish: 7.428kg (1983, Shimna River, Co. Down)
Native species: Yes
Hybrids: Salmon Trout hybrid

Identifying features

Adult fish: eyes above the level of a horizontal line through the tip of the snout; The "wrist" of the tail does not narrow in and then expand again as distinctly as in the salmon; Fresh-run sea trout are blue or green and silver with small, x-shaped black spots; sea run fish which have been in fresh water for a long period will become dark and heavily spotted like brown trout; Microscopic examination of the scales is sometimes necessary to distinguish with certainty between salmon, sea trout and brown trout (it reveals differences in age, growth and migration history)4.

Environment and Habitat

Anadromous; inhabits shallow sea-water adjoining coasts and open ocean as well as freshwater; migratory form of Brown trout1; juvenile sea trout are indistinguishable from juvenile brown trout, but juvenile sea trout  migrate to sea as silvered smolts between April and June after spending two or, less frequently,three winters in freshwater;  they do not travel as far into the marine environment as Atlantic Salmon, usually remaining in coastal waters;  they return to freshwater to spawn either the summer after migration (known as finnock, harvesters, whitling or juniors) or one year or more later (known as maidens); adult sea trout return to sea after a winter in freshwater;  they may return to freshwater many times to spawn which means that  there can besignificant variation in the recorded life history of sea trout 10;

European distribution

Europe and Asia: northwestern coast of Europe 71°N - 34°N, 25°W - 57°E;  in Ireland, usually found in low-productivity rivers before running to sea; particularly abundant along the west coast of Ireland

Economic value in Ireland

Formerly high angling value; stock collapse in recent years due to sea-lice infestations 10;

Red list status

Lower Risk: least concern

Irish legislation status

Sea trout > 40 cm forklength are classified as salmon in terms of legislation and are covered under salmon regulations; commercial and rod harvest of salmon is permitted where stocks are in surplus (exceeding a system-specific Conservation Limit) and the fisheries are very strictly controlled; approximately one third of Irish salmon and sea trout fisheries are open for harvest, with the remainder being open for catch-and release angling or closed to angling; fisheries for Sea trout < 40 cm are open in many areas - more information here.

EU legislation status: