Alien Fish Invasions in Indonesian Inland Waters: Ecological Consequences and Biodiversity Implications

Abstract

Alien fish introductions have become an increasingly significant ecological issue in Indonesian inland waters, largely driven by aquaculture development, fisheries enhancement, and ornamental fish trade. While non-native species contribute to food security and economic growth, their establishment in natural freshwater ecosystems raises concerns for native biodiversity. This study systematically reviews existing literature on alien fish invasions in Indonesia, focusing on their ecological consequences and biodiversity implications. Using a structured review approach across major academic databases, relevant peer-reviewed studies were identified and synthesized. The findings indicate that widely introduced species such as Oreochromis niloticus and Clarias gariepinus are associated with competition, predation, habitat modification, and trophic restructuring. These impacts may alter native fish community composition and contribute to biotic homogenization, particularly in high-endemism freshwater systems. The review highlights the need for strengthened risk assessment, biosecurity measures, and ecosystem-based management to balance fisheries development with long-term biodiversity conservation