Remote Sensing Data Reveal a Significant Reduction in the Area of the Nesting Habitat of Rafetus euphraticus in the Tigris River, Southeastern Turkey

Abstract

The Euphrates Softshell Turtle (Rafetus euphraticus) is an endangered freshwater turtle native to the Tigris‐Euphrates river system. Habitat destruction caused by dams and sand mining poses a major threat to the species. This study quantitatively assesses the occurrence of sandy areas in the upper Tigris in Turkey as a key component of their nesting habitat, utilizing remote sensing data. An ensemble approach was employed, applying and combining Generalized Additive Models (GAM), Generalized Boosting Models (GBM), Generalized Linear Models (GLM), and Random Forests (RF) for classification. The models indicate that, compared to 2018, the occurrence of sandbanks—assumed to be crucial nesting habitat for this species—was reduced by 41% in 2022 following the construction of a large dam. Additionally, sand mining and flooding of adjacent lands have fragmented and degraded the remaining sandbanks. The survival of the Turkish population of the Euphrates Softshell Turtle requires immediate and effective action.