Effect of Climate Change and anthropogenic pressures on the European eel Anguilla anguilla from RAMSAR Wetland Ichkeul Lake: prediction from the Random Forest model

Abstract

The present study aims to assess the trophic level of Ichkeul ecosystem and predict the effect of climate change and anthropogenic pressures on European eels. Multimetric trophic index (TRIX) and Random Forest (RF) model were performed using a dataset consisting of 14 parameters for the period 2010-2020. The observed TRIX values inside the lake show a non-uniform distribution and a variation between seasons reflecting poor water quality mainly in the river's discharges. While the RF model outcomes show that the most important predictors of eels landing appear to be water level, followed by turbidity and salinity. These results are consistent with the relationships found with the Pearson Correlation. For comparison, the RF model yielded an R 2 of 58.4 % while the Multiple Regression Linear MLR yielded an R 2 of 40.3 %, confirming that the RF model is significantly better than the MLR and that the model predictions are statistically reliable. This study also demonstrated that the sustainable approach, which combines the two models, can be used in decision-making by civil authorities and other interested stakeholders.