Abstract
Non-native fish (NNF) can threaten megadiverse aquatic ecosystems throughout the planet, but limited information is available for the Amazon Region. In this study we review NNF data in the Amazonian macroregion using spatiotemporal records on the occurrence and the richness of NNF from a collaborative network of 35 regional experts, establishing the Amazon NNF database (ANNF). The NNF species richness was analyzed by river basin and by country, as well as the policies for each geopolitical division for the Amazon. The analysis included six countries (Brazil, Peru, Bolivia, Ecuador, Venezuela, and Colombia), together comprising more than 80% of the Amazon Region. A total of 1314 NNF occurrence records were gathered. The first record of NNF in this region was in 1939 and there has been a marked increase in the last 20 years (2000–2020), during which 75% of the records were observed. The highest number of localities with NNF occurrence records was observed for Colombia, followed by Brazil and Bolivia. The NNF records include 9 orders, 17 families and 41 species. Most of the NNF species are also used in aquaculture (12 species) and in the aquarium trade (12 species). The most frequent NNF detected were Arapaima gigas, Poecilia reticulata and Oreochromis niloticus. The current data highlight that there are few documented cases on NNF in the Amazon, their negative impacts and management strategies adopted. The occurrence of NNF in the Amazon Region represents a threat to native biodiversity that has been increasing “silently” due to the difficulties of large-scale sampling and low number of NNF species reported when compared to other South American regions. The adoption of effective management measures by decision-makers is urgently needed and their enforcement needed to change this alarming trend and help protect the Amazon’s native fish diversity.
Highlights
The current worldwide biodiversity crisis has been characterized by an unprecedented rate of species loss, introduction of nonnative organisms, biological invasions and biotic homogenization (McGeoch and Jetz, 2019; Padial et al, 2020)
Ecological traits and invasion vectors or pathways of the recorded NNF species were compiled from FishBase (Froese and Pauly, 2019) and used to identify major characteristics related to NNF in the Amazon (Supplementary Material 3)
The most recent research pointed to 5 (Tedesco et al, 2017) and ∼18 (Gubiani et al, 2018; Jézéquel et al, 2020) NNF species recorded in the Amazon, while the present study unveiled more than twice as many NNF species in the region
Summary
The current worldwide biodiversity crisis has been characterized by an unprecedented rate of species loss, introduction of nonnative organisms, biological invasions and biotic homogenization (McGeoch and Jetz, 2019; Padial et al, 2020). South America was indicated as one of the six freshwater fish global invasion hotspots of the world, with 5–20 NNF species recorded for the Paraná-Paraguay-Amazon river systems more than a decade ago (Casal, 2006; Leprieur et al, 2008). In the Amazon Region (hereinafter Amazon) there are many evidences of increasing propagule pressure due to accidental NNF introductions through fish farming without effective escape barriers, or by river overflooding in fish farming areas (CarvajalVallejos et al, 2011; Van Damme et al, 2017; Doria et al, 2020). Introductions of NNF have clear negative impacts on native fish assemblages, leading to local species extinctions, reducing genetic diversity, causing loss of ecosystem functions, habitat disruption (Vitule, 2009; Cucherousset and Olden, 2011), and homogenization or differentiation (Toussaint et al, 2016b) at genetic, taxonomic, and functional levels (Olden et al, 2004). Understanding spatial and temporal trends in NNF invasions is an important milestone for mitigating their negative impacts on biodiversity, especially in global biodiversity hotspots such as the Amazon
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
