Fish and fisheries

Fish and fisheries of the Tweed catchment

Atlantic salmon, Salmo salar, on its amazing journey upstream to spawn

The international reputation of the River Tweed, both as a famous salmon river and an excellent brown trout water, is well-deserved. Salmon and trout angling attracts sport fisherman from around the world and brings substantial benefits to the local Borders economy. A survey in 2015 found the value of the fishing industry to be £24 million to the local economy, providing 513 (full-time equivalent) jobs. Below you’ll find a brief introduction to the fish species found within the Tweed catchment, as well as the catchment’s fisheries and statutory protections.

Fish species

The Tweed catchment no longer has a natural assemblage of fish species due to introductions, both deliberate and accidental, of non-native species over the years. Unlike rivers further to the south, which were connected to the continent as the last Ice Age ended, the Tweed has always had a salt-water barrier between it and Europe. Therefore, only those fish species that could tolerate saltwater conditions at some stage in their life cycle could colonise the river naturally. These original species were:

Atlantic Salmon: resident in freshwater for one to four years, then migrates to the North Atlantic to grow for one to three years, before returning to their home area to spawn and, in 90-95% of cases, die.
Sea and Brown Trout: brown trout live wholly in freshwater whereas sea trout migrate to sea, before returning to their home area to spawn.
Arctic Charr: in colder conditions this species migrated to the sea but as temperatures rose after the end of the Ice Age, migration in this part of the world stopped, leaving isolated freshwater populations, such as the one that used to live in St Mary’s Loch. This became extinct in the early 19th Century through overfishing and predation. The species was re-introduced into the Borders reservoirs Megget and Tall in the late 1980s, with individuals from Loch Doon (Ayrshire), as a means of safeguarding the Loch Doon population for future generations.
European Eel: resident in freshwater before migrating to the Sargasso Sea to spawn and die.  Larger specimens can live up to twenty years in freshwater.
Three-spined Stickleback: predominantly lives in freshwater but is saltwater tolerant.
Sea Lamprey: spawns in freshwater but feeds and matures in the sea.
River Lamprey: spawns in freshwater but feeds and matures in the sea and estuaries.
Brook Lamprey: a purely freshwater form that lives most it its life as a filter-feeding larvae, before maturing to an adult form that does not feed and dies after spawning.

Whilst the Flounder can live in freshwater miles from the sea, it has to return to the sea to spawn. The Allis Shad is a regular visitor to the Tweed estuary and has been found up to 45 miles upriver. Although the marine Allis Shad spawns in freshwater, it is not known if it does so in the Tweed.

These indigenous species have been joined by purely freshwater fish such as the Grayling, Beardie, Pike, Perch, Dace, Rainbow Trout and Baggie/Minnow. Grayling (a relative of Trout and Salmon) were introduced in 1855 as sport for the winter months and the Tweed now features a population of considerable sporting interest. The Beardie (known in England as the Stone Loach) was regarded as a food fish in the past. Pike and Perch were probably introduced to lochs and ponds as food fish in the Middle Ages, whereas Roach arrived in the late 19th century, escaping from a pond near Wooler where they had been introduced as a source of bait for Pike fishing. Dace seem to have arrived in the 20th Century by unknown means. How the Baggie/Minnow arrived is unknown – such a small fish could have arrived naturally by some means (eggs on the feet of birds for example) or accidentally introduced whilst being used as fish bait.

Statutory protection

The River Tweed has had its own salmon legislation for a very long time in the form of Acts passed during the reigns of George III, George IV and William IV. Protection of Tweed Salmon and Sea Trout has been the responsibility of the River Tweed Commissioners since their creation under the Act of 1807 in the reign of George III. However, the most important historic Tweed Salmon Acts were those of 1857 and 1859, while the Tweed Act of 1969 included certain provisions for the protection of freshwater fish. Many sections of these Acts have been repealed by Salmon and Freshwater Fisheries Acts pertaining to Scotland generally, and these include the Salmon and Freshwater Fisheries (Protection) (Scotland) Act 1951 and the Freshwater and Salmon Fisheries (Scotland) Act 1976. A Protection Order, in force on the Tweed, has been made under the provisions of this latter Act which have made it an offence to fish for trout without written consent. The Salmon Act of 1986 covered the United Kingdom as a whole and enabled those responsible for law enforcement on a salmon river to prohibit fishing for salmon, prawns and shrimps. This restriction is in force on the Tweed. A major consolidation of the Tweed Act of 1969 with other Tweed fisheries legislation came about in the Scotland Act 1998 (River Tweed) Order 2006 (‘The Tweed Order’). The Tweed Order renamed the River Tweed Commissioners as the River Tweed Commission and charged them with “the general preservation and increase of Salmon, Sea Trout, Trout and other freshwater fish in the River Tweed and its tributaries, and in particular with the regulation of fisheries, the removal of nuisances and obstructions and the prevention of illegal fishing“.  The Tweed Regulation (Salmon Conservation) Order 2016 ensures that any killing of wild Atlantic Salmon is managed according to the conservation status of the river.

The fisheries

Commercial salmon fishing in the Tweed district dates back at least 1000 years, however, it is mostly now defunct, with the vast majority of netting stations closed down. The Salmon and Sea Trout angling season lasts from 1st February to 30th November. There are two significant “runs” of Salmon, one in the spring and a much larger run in the autumn. By contrast, Sea Trout runs mainly in the summer with smaller spring and autumn runs. Trout angling generally commences on the 1st April and continues until 30th September although some clubs operate a slightly longer season. Whilst the high demand, especially in the autumn, limits the availability of Salmon fishing, fishing for Trout and other freshwater fish species is readily available through the many angling associations. FishTweed and Tweedbeats provide detailed information on freshwater angling within the Tweed catchment, including on- and offline booking systems.


The River Tweed Commision and the Tweed Foundation are the primary bodies concerned with fish conservation within the Tweed catchment. The River Tweed Commission is required by law to protect and improve Salmon and other freshwater fisheries of the Tweed catchment and, in the early 1980s, established the Tweed Foundation as the delivery mechanism for fisheries management on Tweed. The Tweed and Eye District Fisheries Management Plan represents the work of the Foundation in collecting and analysing relevant data to arrive at a sustainable management policy for the Tweed’s fisheries. You can find out all the latest from the River Tweed Commission and Tweed Foundation at their joint news site It should also be noted that much of Tweed Forum’s work is complementary to fisheries conservation, particularly work on barrier removal at various sites such as Haughhead and Lilburn.