Nile Tilapia (Oreochromis niloticus Linnaeus, 1758) Invasion Caused Trophic Structure Disruptions of Fish Communities in the South China River—Pearl River

Abstract

Widespread introductions of non-native species, including aquaculture and ornamental species, threaten biodiversity and ecosystem functioning by modifying the trophic structure of communities. In this study, we quantified the multiple facets of trophic disruption in freshwater communities invaded by Nile tilapia, by comparing uninvaded and invaded rivers downstream of the Pearl River, China. Nile tilapia invasion reduced the trophic status of native fish species by forcing native herbivores and planktivores to seek new food sources. The food chain was also shortened by decreasing the trophic levels of native invertivores, omnivores, and piscivores, while the total isotopic niche area (TA) of native invertivores, omnivores, piscivores, and planktivores species also decreased. Simultaneously, Nile tilapia invasion affected the isotopic diversity of the fish community. Decreasing isotopic richness (IRic), isotopic evenness (IEve), and increasing isotopic uniqueness (IUni) indicated that Nile tilapia had a high trophic niche overlap with native species and competed with native species for food resources, and even caused the compression of the trophic niche of native species. Understanding the process described in this study is essential to conserve the stability of freshwater ecosystems, and improve the control strategy of alien aquatic organisms in south China.

Climate Change May Impact Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758) Distribution in the Southeastern Arabian Peninsula through Range Contraction under Various Climate Scenarios

“…In particular, non-indigenous/exotic tilapias, especially the Nile tilapia, Oreochromis niloticus, are among the most successful and harmful fish invaders globally. The Nile tilapia is a cichlid fish native to Africa that has been successfully introduced to at least 100 countries, including countries of the Arabian Peninsula, for aquaculture due to its high growth rate, resistance to diseases, tolerance to various environmental conditions, high meat quality, and high production [16][17][18]. At present, it is one of the most important freshwater species used in aquaculture worldwide [18].…”

“…The Nile tilapia is a cichlid fish native to Africa that has been successfully introduced to at least 100 countries, including countries of the Arabian Peninsula, for aquaculture due to its high growth rate, resistance to diseases, tolerance to various environmental conditions, high meat quality, and high production [16][17][18]. At present, it is one of the most important freshwater species used in aquaculture worldwide [18]. Due to its capacity to cause a series of environmental and ecological problems, i.e., changes in water quality, habitat degradation, trophic cascades, and modifications of ecosystem function [18,19], O. niloticus is currently known as one of the most hazardous invasive fish in the tropical and subtropical areas of the world [18,20].…”

“…At present, it is one of the most important freshwater species used in aquaculture worldwide [18]. Due to its capacity to cause a series of environmental and ecological problems, i.e., changes in water quality, habitat degradation, trophic cascades, and modifications of ecosystem function [18,19], O. niloticus is currently known as one of the most hazardous invasive fish in the tropical and subtropical areas of the world [18,20].…”