Native Fish and Anuran Assemblages Differ between Impoundments with and without Non-Native Centrarchids and Bullfrogs

Centrarchids (sunfish and bass species) and Bullfrogs (Lithobates catesbeianus) have been introduced into aquatic systems around the world and have the potential to negatively impact native fish and anurans. We surveyed fish and anuran assemblages from 26 impoundments in the New Jersey Pinelands, USA. We excluded non-native species and used ordination analysis to generate four native-species community gradients based on native-fish and anuran presence–absence and abundance data. All four community gradients paralleled an increase in the percentage of upstream-altered land (development and upland agriculture) and an increase in either non-native-centrarchid richness or abundance. Based on presence–absence and abundance data, native-fish and native-anuran assemblages, including restricted species (those generally limited to the Pinelands region) and widespread species (those widely distributed in New Jersey), differed between impoundments with and without non-native centrarchids. Compared to widesp...