Assessment of vulnerability and adaptation of Caspian Sea sturgeon in the face of future climate changes

Sturgeon are valuable species that stocks have reached the brink of extinction for various reasons such as overfishing, habitat destruction, and pollution. Despite the poor condition of sturgeon stocks, today climate change has posed another new and serious threat to these fish. In the meantime, analysis of the effects of global warming on the Caspian Sea and ecosystems related to the living environment of sturgeon is very necessary. In this study, an appropriate set of consequences of climate change on the vulnerability and adaptation of sturgeon in the Caspian Sea was prepared using library research and expert opinions in the form of a researcher-made questionnaire and an expert group consisting of 21 experts related to Fishery and sturgeon basins as well as climate change experts were distributed. The results showed that by increasing the water level and decreasing salinity, we can see positive effects in improving the state of natural reserves and increasing the reproduction and breeding efficiency of sturgeon. Also, increasing the temperature will have a positive effect on the reproduction and breeding of sturgeon due to the increase in the length of the temperature period suitable for breeding and feeding sturgeon and will have no effect on stocks. However, in contrast to the decrease in rainfall in other parts of the Caspian catchment area will reduce the discharge of rivers and will have a significant impact on reducing reserves and reducing the breeding efficiency of these valuable fish. Also, increasing acidity, increasing the incidence of planktonic blooms and drastic changes in sea currents will have negative effects on these cases. However, it should be noted that the entry of pollutants into water resources, the occurrence of planktonic blues, the entry of invasive species and many other changes, intensify the destructive effects of climate change. In order to adapt to the consequences of climate change, by adopting the managerial and executive measures presented in this study for the protection and sustainable use of valuable sturgeon reserves in the Caspian Sea, the negative effects can be mitigated.