Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root brak. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
The beluga, also known as the beluga sturgeon or great sturgeon, is a species of anadromous fish in the sturgeon family (Acipenseridae) of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and formerly in the Adriatic Sea. Based on maximum size, it is the third-most-massive living species of bony fish. Heavily fished for the female's valuable roe, known as beluga caviar, wild populations have been greatly reduced by overfishing and poaching, leading IUCN to classify the species as critically endangered.
The Caspian seal is one of the smallest members of the earless seal family and unique in that it is found exclusively in the brackish Caspian Sea. It lives along the shorelines, but also on the many rocky islands and floating blocks of ice that dot the Caspian Sea. In winter and cooler parts of the spring and autumn season, it populates the northern Caspian coastline. As the ice melts in the summer and warmer parts of the spring and autumn season, it also occurs in the deltas of the Volga and Ural Rivers, as well as the southern latitudes of the Caspian where the water is cooler due to greater depth.
The Danube bleak or Caspian shemaya is a species of freshwater fish in the family Cyprinidae. It is found in Iran, Ukraine, Georgia, Armenia, Slovakia, Moldova, Greece, Czechia, Azerbaijan, Turkiye, Afghanistan, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Switzerland, Germany, Hungary, Italy, Romania, Russia, Serbia, Slovenia, Turkmenistan, and Uzbekistan.
Pelecus cultratus, commonly known as the ziege, sichel, sabre carp or sabrefish, is a cyprinid fish species from Eastern Europe and adjacent Asian regions, the only one in its genus, inhabiting the lower reaches of rivers and brackish waters in the eastern Baltic Sea, Black Sea, Caspian Sea and Aral Sea basins. The ziege having no major threats, the IUCN lists it as being of Least Concern.
The big-scale sand smelt is a species of fish in the family Atherinidae. It is a euryhaline amphidromous fish, up to 20 cm in length.
Benthophiloides brauneri is a species of goby, a benthophilic fish native to the fresh and brackish waters of the Black Sea, the Caspian Sea and the Sea of Azov as well as their surrounding rivers and estuaries. Despite the wide distribution, very few observations overall of this fish exist, and just one from the Caspian basin. It has been found in still waters at depths down to around 15 metres (49 ft). Males of this species can reach a length of 7.2 centimetres (2.8 in) SL while females only reach 5.1 centimetres (2.0 in) SL. This fish only lives for one year.
The monkey goby is a species of goby native to the basins of the Black Sea and the Sea of Azov.
The racer goby is a species of goby native to fresh, sometimes brackish, waters, of the Black Sea basin. It is a Ponto-Caspian relict species. The species is placed a monotypic genus, Babka, which was once considered a subgenus of genus Neogobius, but was then elevated to genus-status based on the molecular analysis.
Ponticola kessleri, the bighead goby or Kessler's goby, is a species of goby native to Eurasia. The bighead goby is a Ponto-Caspian relict species. It inhabits the fresh and oligohaline waters, with mineralisation from 0-0.5‰ up to 1.5-3.0‰.
Common percarina is a species of fish in the family Percidae. It is found in northwestern Black Sea basin in estuaries and coastal lakes, and in the lower reaches of the rivers that drain into that part of the Black Sea. It is a carnivorous species.
Mytilopsis leucophaeata is a species of small bivalve mollusc in the false mussel family, Dreissenidae. It is commonly known as Conrad's false mussel or the dark false mussel.
The western tubenose goby is a species of goby native to fresh waters of the Black Sea and Aegean Sea basins. It has recently spread as an invasive species to Central and Western Europe and to North America. Previously Proterorhinus semilunaris was considered as a junior synonym of Proterorhinus marmoratus, but was confirmed as a distinct species based on molecular analysis.
The eastern tubenose goby is a species of gobiid fish native to fresh and brackish waters of the basins of the Sea of Azov and the Caspian Sea and has invaded the upper reaches of the Volga River from its native occurrence in the delta. This species prefers slow flowing rivers or still waters with plentiful rocks or vegetation. It can reach a length of 9 centimetres (3.5 in) SL. It is probably the same species as that recently treated as Proterorhinus semipellucidus.
The Black Sea tadpole-goby is a species of goby native to the basin of the Black Sea. Found in the Gulf of Tendra and limans of the north-western Black Sea, lakes of the Danube Delta. In the rivers of the Black Sea basin: Danube up to Iron Gate dam, Dniester up to Tighina, Dnieper up to Kyiv, Southern Bug. This species is mostly a denizen of fresh and slightly brackish bodies of water, preferring rivers and deltas, limans and coastal lakes. This fish can reach a length of 15 centimetres (5.9 in) TL.
Ponticola gorlap, or the Caspian bighead goby, is a species of goby, a benthic fish native to the Caspian Sea basin. It is widespread in lower parts of many rivers in Iran, and also found in Azerbaijan and Turkmenistan. In Russia, it occurred in the lowest part of the Volga River up to Astrakhan until 1977, but has thereafter spread upstream. In 2000 it was recorded as being established in the Ivankovo and Rybinsk Reservoirs in the Moscow region, and already invaded the Don drainage by way of the Volga-Don Canal in 1972. This species occurs in sheltered environments, such as inshore fresh or brackish waters of estuaries, lagoons, lakes and large rivers, where it prefers habitats with a well vegetated rock or firmly packed sand substrate. It can reach a length of 20 centimetres (7.9 in) SL, and a common size is 12 centimetres (4.7 in) SL.
The Caspian tadpole goby is a species of goby which is widespread in the basin of the Caspian Sea, specifically in the near-estuary zone of the rivers and in small bays. It is a common species in the Volga River delta near Astrakhan, occurred in the deltas of rivers Terek, Ural, Samur. During the warmer months, this species prefers to live at depths of from .5 to 10 metres, moving in the colder months to depths of 20 to 25 metres. It can reach a length of 11.6 centimetres (4.6 in) TL.
The granular pugolovka is a species of gobiid fish widespread in the Caspian Sea. It is a small fish, with a length up to 5.6 centimetres (2.2 in) TL. It was listed as Least Concern by the IUCN in 2008: there are no known major threats. Granular pugolovkas are very abundant in their habitat due to their size and lack of natural predators. The common name 'pugolovka' is a Ukrainian word for tadpole.
The small-spine tadpole-goby is a species of goby, a small fish native to the eastern coasts of the Caspian Sea and the lower reaches of the Volga River up to Volgograd. In the sea it is recorded from the Cape Peschany to the Çeleken Peninsula and Ogurja Ada Island in the south. It is abundant the Volga River delta. This species can be found at depths down to 50 metres (160 ft) although the adults generally are not found deeper than 11 metres (36 ft). This species can reach a length of 6.6 centimetres (2.6 in) TL. The specific name honours the Azerbaijani ichthyologist A. A. Mahmudbekov, studied the fish of the Caspian Sea for much of his life.
The wildlife of Ukraine consists of its diverse fauna, flora and funga. The reported fauna consists of 45,000 species when including the areas of the Black Sea and the Sea of Azov. Ukraine's protected environments consist of 33 Ramsar sites covering an area of 7,446.51 square kilometres (2,875.11 sq mi). Biosphere nature reserves and three national parks are all part of the GEF projects portfolio of conservation of biodiversity in the Danube Delta. Their vegetation pattern is mixed forest area, forest-steppe area, steppe area, Ukrainian Carpathian Mountains and Crimean Mountains. Some of the protected areas that were reserves or parks are subsumed under the biosphere reserves.
