Species Distribution Modeling (Present–Future)
Our study clearly showed the impact of climate change on the distribution of non-native H. leucisculus in Iran’s freshwater. The current maps show the suitable distribution for the species, which could occur in a wider distribution range especially in some regions out of the recorded areas (Fig. 4). According to Carosi et al. (2019), species can experience four scenarios under climate-change effects (i.e. reduction, expansion, both, or stable) in their habitats. Based on the output maps of Climate change modelling under SSP scenarios, it will be predicted that climate change would significantly affect the distribution of H. leucisculus as it showed a sharp tendency to expand over time in its distribution areas (Fig. 4). In connection with our results, Mamun et al. (2018) predicted future climate-change effects on an invasive alien species Micropterus salmoides in the Korean peninsula for 2050 and 2100. According to their results, the potentially suitable habitats for M. salmoides are most likely to increase by 2050 and 2100.
Moreover, the output of the modelling absolutely showed that in areas with high human population density, the probability of H. leucisculus distribution in the future is also more. This is due to the high human activities, trade and travel in these areas.
The expansions of H. leucisculus into upstream and downstream areas are likely to be the effect of the temperature rise and due to the warm water of this species. It was expected that climate change would benefit this species; temperature illustrated the most important role for model predictions in line with these results, Hong et al. (2022) with SDM tools applied to explore predicted range shifts in two invasive alien fish species under future climate-change scenarios. They plainly presented that range shifts increased under climate-change scenarios and temperature is the most reason for the expansion of alien fishes.
It is mentioned that with expansions of alien species the vulnerability of native species will probably be more significant (Hansen et al., 2017; Abdoli et al., 2022; Kim et al., 2022) and it results in lowering the species diversity and degrading the sustainability of native fish species(Jang et al., 2006).