Aquaculture facilities drive the introduction and establishment of non-native Oreochromis niloticus populations in Neotropical streams

• Published in: Hydrobiologia Vol. 848; no. 9; pp. 1955 - 1966
• Main Authors: Forneck, Sandra Carla, Dutra, Fabrício Martins, de Camargo, Mariele Pasuch, Vitule, Jean Ricardo Simões, Cunico, Almir Manoel
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.05.2021; Springer; Springer Nature B.V
• Subjects: Aquaculture; Aquaculture facilities; Aquaculture industry; Biodiversity; Biological diversity conservation; Biomedical and Life Sciences; Brazil; Ecology; Ecosystems; Fish-culture; Fishes; Freshwater & Marine Ecology; Freshwater fishes; Invasive Species III; Life Sciences; Marine fishes; Methyltestosterone; Natural environment; Neotropics; occupations; Oreochromis niloticus; Ponds; Pressure; Rivers; Streams; Tilapia; Watersheds; Wildlife conservation; Zoology; Brazil; Colonization success; Neotropical streams; Freshwater ecosystems; Introduction effort; Nile tilapia; Escapes
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-020-04430-8

This study investigated whether aquaculture facilities drive the introduction and establishment of the non-native Nile tilapia ( Orechromis niloticus ) in Neotropical streams, Brazil. Samples were taken from nine streams with different aquaculture occupation intensities (no, moderate, and intense) using the percentage of occupation of micro-watersheds by aquaculture ponds as a proxy for propagule pressure. The presence of aquaculture facilities and the percentage of aquaculture occupation were good predictors of the catch frequency and of densities of tilapias in the adjacent natural environment. In the streams under intense propagule pressure, females prevailed and high densities of young individuals comparing to adults were recorded. It suggests that the species was reproductively successful in the natural environment. In the streams under moderate propagule pressure, males prevailed, which indicates the likely capture of individuals escaped from aquaculture facilities. In general, our results show the positive influence of propagule pressure on the introduction and establishment of Nile tilapia in natural ecosystems, showing that aquaculture expansion of O. niloticus poses a threat to the conservation of aquatic biodiversity.