This research analyzes the ecological differences between selected sites (Pond 1 and Pond 2) and how these differences affect the sampled populations of newts. Newts were sampled using electrofishing (only individuals of great crested newts with a net) and their morphological characteristics were recorded. I compared the two populations of newts from Pond 1 and Pond 2. The ponds are ecologically similar, with the main difference being the presence of non-native fish species. In Pond 2, where non-native fish species are present, there is lower density of individuals and species diversity. In Pond 1, all three expected species of newts (smooth newt, great crested newt, and alpine newt) are present, while in Pond 2, only two species of newts (smooth newt and alpine newt) are found. A statistically significant difference in total body length (TL) was observed in males and females of smooth newts and great crested newts from Pond 1. Males and females of smooth newts from Pond 1 have larger total body lengths than individuals of the same species from Pond 2. A statistically significant difference in sex ratio was recorded in males and females of great crested newts from Pond 1. Principal component analysis (PCA) did not show significant separation among species, sexes, and populations of newts between the selected sites. Non-native fish species sharing the same aquatic habitat with newts negatively affect them by competing for food and preying on the eggs, larvae, and adult newts. I removed 16 carp and 103 goldfish using electrofishing. Active participation in controlling invasive fish species is necessary to preserve newt populations.