The Red Book of the Republic of Belarus includes 9 species of fish: sterlet, Atlantic salmon, brown trout, river trout, European grayling, European smelt, lake minnow, common barbel, and vimba bream. Fishing for these species is prohibited.
Sterlet. The only species of the sturgeon family living in the wild in Belarusian rivers such as the Pripyat, Sozh, Berezina, Dnieper, and their tributaries. Individuals typically measure 40-60 cm in length and weigh up to 1 kg, although some specimens can grow over 1 m long and weigh around 16 kg. Sterlet is a schooling bottom-dwelling fish, preferring deep river sections and flowing pits with sandy or gravelly bottoms. It spawns at temperatures above 10°C from late April to early May in the upper reaches of rivers.
In 1948-1954, sterlet was introduced into the Western Dvina in Latvia and the Neman in Lithuania. However, sterlet did not acclimatise in the same rivers within Belarus. Currently, broodstocks of sterlet have been established in some fish farms in the republic, allowing for the production of stocking material for restocking rivers with this valuable species. In 2006, 5,000 young sterlets were released into the Berezina River, in 2016, about 900 individuals were released into the Pripyat River, and in 2017, 1.9 thousand sterlets were introduced into the Dnieper on the Belarusian side and 30,000 individuals into the transboundary section from the Russian side.
Atlantic salmon (Salmo salar) and brown trout. These are migratory species of the salmon family. Salmon can reach lengths of 1.5 m and weights of 32 kg, while brown trout grow up to 1 m and 12 kg. While most of the brown trout's body is covered with numerous black spots, salmon have virtually no spots below the lateral line.
Until the 1950s, salmon and brown trout entered the Western Dvina, Neman, and Viliya rivers from the Baltic Sea to spawn. Today, both species are found during spawning (in October-December) in the watercourses of the Viliya River basin within the Ostrovets and Smorgon districts of the Grodno region. Despite the long migrations undertaken by salmonids during their sea life, most of them return to spawn in the same rivers and even the same spawning grounds where they themselves hatched. During spawning, these fish do not feed, and therefore, after spawning, many salmon die from exhaustion.
Brown Trout. This is a freshwater, landlocked form of the brown trout. It inhabits small rivers and streams with clean, cold water. It is widespread in the Neman and Viliya river basins. Spawning occurs in November-December on riffles with sandy or gravelly bottoms. Trout growth is quite rapid but highly dependent on habitat conditions: large individuals are found in large rivers with a sufficient food base, while large individuals are not observed in small streams with insufficient food. The body length of trout reaches 22-55 cm, and the mass is 0.2-2 kg.
European Grayling. The only representative of the grayling family in Belarus. It is one of the most beautiful fish. Its coloration is bright, especially during the breeding season. There are small dark spots on its back and sides, and large dark spots on its high dorsal fin. The lifestyle of the grayling is similar to that of the stream trout.
Within the republic, grayling inhabits cold-water streams with high oxygen content in the Neman River basin. It leads a sedentary lifestyle. Spawning begins with the spring rise in water temperature to 7-9 degrees Celsius in late April – early May. It feeds mainly during twilight hours.
European Smelt (Kilka). It inhabits the lakes of Belarus and differs from migratory smelt in its significantly smaller size – 6-10 cm. It is found in the Western Dvina River basin – in the lakes Drivyaty, Snudy, Strusto, Volos, Rychi (Braslav district), Dolgoye (Glubokoye district), Rudakovo (Myadel district). It is a schooling fish that stays near the shore at considerable depths. The population of smelt in Belarusian lakes, as a fish with a short life cycle (2-3 years), is subject to sharp fluctuations due to changes in natural reproduction conditions – pollution, silting, and overgrowth of spawning grounds.
Lake Minnow. Unlike the river minnow, the lake minnow can be found in lakes heavily overgrown with vegetation. This species tolerates low oxygen content in the water without consequences. It somewhat resembles the tench, which is why it is sometimes called "linok" (little tench). It plays an important role in the food chains of water bodies, as it serves as food for predatory fish. Spawning is hidden and occurs from May to July.
Common barbel. A semi-migratory fish of the carp family, reaching a length of 40-60 cm and a weight of 2-3 kg. It inhabits the bottom, predominantly stony-sandy, and is mainly nocturnal. It undertakes significant spawning migrations. It is found in the Neman, Viliya, and Western Bug rivers and their tributaries. The Dnieper barbel is found in the Dnieper River and its tributaries – Berezina, Drut, Pripyat, and Sozh.
The main factors limiting the barbel population are river pollution and increased water turbidity. To restore stocks, artificial reproduction needs to be organised.
Vimba bream. Considered a migratory fish that enters rivers for spawning from the estuary areas of seas, however, within Belarus, it is a typically freshwater form. It is found in the basins of the Western Bug, Neman, Western Dvina rivers, and the upper reaches of the Dnieper. It reaches a length of 50 cm and a weight of 3 kg. Due to its high demands for spawning grounds, the vimba bream undertakes long migrations to the upper reaches of rivers in early spring. The main measure to increase its population is the melioration of natural and the creation of artificial spawning grounds.
Fishing for Red Book species is prohibited. If such fish are caught unintentionally, they should be released back into the water.