Freshwater fish of scotland

The Atlantic Salmon is an anadromous species of salmon which is found in most of the river systems of Scotland. They spawn in rivers, then the young head out to sea to feed, before returning after at least one year to spawn again. Although little is known about their migration patterns, it is known that they are excellent navigators, with individual populations return to the exact same spawning grounds year after year. They spawn in late autumn and winter, after which a majority of the adults die, however a small number will make it back to the sea and return to spawn again. The Salmon's diet varies throughout its life cycle. The juveniles feed in fresh water on small invertebrates and small fish. The adults feed at sea on sand eels, squid, herring and shrimp. The Salmon is subject to extensive commercial fishery, however farmed salmon is becoming more prevalent and dependence on wild stocks is not as high. Salmon returning after one winter at sea (grilse) are not subject to protection, however larger salmon which have spent more than one winter at sea are protected under British law. less ↑

The Brown Trout is found in most rivers and lochs in Scotland. some populations reside permanently in fresh water while some are anadromous (sea trout). The Brown Trout feeds on insects, insect larvae, and as they get larger, smaller fish. Some populations are isolated in deep lochs and grow to much larger than average size by feeding on Arctic Char, these are known as Ferox Trout. The Brown trout spawns during the autumn and winter, from October through to January. All the variants spawn in rivers, regardless of whether they have been in salt water or not. Brown Trout are not subject to extensive commercial fishing, however they are fished for by recreational anglers as they are good to eat. They are not currently a threatened species. less ↑

The Arctic Char, according to Scottish Natural Heritage, was the first fish to re-colonise fresh waters in Scotland after the last ice age. It is found in numerous deep, cold lochs across Scotland. It feeds on a varied diet, consisting of such foods as insects, salmon eggs and plankton. The Char spawns in the autumn, from September to November. Arctic Char in Scotland are not subject to commercial or subsistence fishing, they are caught by a small number of recreational anglers, but this is not thought to be a threat to their population. Scottish Natural Heritage lists climate change and lake acidification as the most prominent threats to the Arctic Char. It is a protected species in a number of lochs, and populations also occur in lochs which are protected for other reasons. less ↑

Coregonus lavaretus, known as the Powan in Scotland is one of the rarest Scottish freshwater fish. According to Scottish Natural Heritage, natural populations occur in only two lochs, Loch Lomond and Loch Eck. fish from these populations have been transplanted to other lochs in order to establish populations as part of a conservation effort. the Powan is under threat from the Ruffe, an invasive species which eats Powan eggs. the Powan is on the IUCN red list of threatened species and is a protected species under British law. less ↑