Forecasting Environmental Drivers and Invasion Risk of Lagocephalus sceleratus (Gmelin, 1789) and Pterois miles (Bennett, 1828) in the Pagasitikos Gulf (Greece)

The Eastern Mediterranean Sea has become a hotspot for biological invasions, with thermophilic species like Lagocephalus sceleratus (silver-cheeked toadfish) and Pterois miles (devil firefish) posing significant ecological and socioeconomic threats. Machine learning models (support vector machine and neural network) were developed to predict species establishment, demonstrating high predictive accuracy. SHapley Additive exPlanations analyses further highlighted the relative influence of environmental predictors. Nominal logistic regression identified bottom temperature and salinity as the key environmental drivers for the establishment of these species, with thresholds of 16.38 °C and 39.14 psu for P. miles and 15.84 °C and 39.09 psu for L. sceleratus. Forecasts through 2035, generated using the Prophet model, have predicted warming bottom temperatures but declining salinity levels, creating variable conditions for invasion. Long-term suitability was assessed by comparing forecasted conditions against thresholds, revealing that salinity and chlorophyll a consistently fall below suitable levels for both species. L. sceleratus showed stable suitability with occasional declines, while P. miles exhibited greater variability. These findings underscore the importance of fine-scale benthic data and integrated modeling approaches for early detection and adaptive management of invasive species in Mediterranean ecosystems. The study provides clear thresholds to guide ongoing environmental monitoring and emphasizes the need for continuous assessments to anticipate future invasion risks under changing climatic conditions.