“Sea Water Rise” Scenario and Potential Ichthiodiversity Challenges in Lower Dniester River–Floodplain-Delta–Black Sea Area (Petromyzontidae, Acipenseridae, Anguilidae, and Cyprinidae)

The Dniester Delta is one of the Earth’s biodiversity hotspots and is home to many fish species of conservation and economic value. This unique complex of aquatic and semi-aquatic wetland habitats is also essential for the diversity of Dniester River and Black Sea ichthyofauna due to its role as a natural safe buffer and as a shelter, feeding, reproduction, and smooth transitional area for numerous fish species. Climate change is causing constant sea level rises in the Black Sea, which is anticipated to impact the vital ecosystems and related biodiversity in the Dniester Delta and other lower flooding areas, including the key ecological taxonomic group of fish. From this sea water rise risk assessment study of a total of 41 fish species, 6 were found to be under very high risk in the studied areas, 12 under high risk, 17 under moderate risk, and 6 under low risk. Positive ecological feedback in fish can stimulate environmental change and is expected to be responsible for changes within the Dniester Delta region complex of ecosystems in the context of sea level rise in the Black Sea, in addition to the diverse matrix of aquatic and semi-aquatic ecosystems in the near Dniester River and Black Sea.