Freshwater fish diversity hotspots for conservation priorities in the Amazon Basin

Abstract

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify biodiversity hotspots based on 6 conservation templates (3 proactive, 1 reactive, 1 representative, and 1 balanced) to provide a set of alternative planning solutions for freshwater fish protection in the Amazon Basin. We identified empirically for each template the 17% of sub-basins that should be conserved and performed a prioritization analysis by identifying current and future (2050) threats (i.e., degree of deforestation and habitat fragmentation by dams). Two of our 3 proactive templates had around 65% of their surface covered by protected areas; high levels of irreplaceability (60% of endemics) and representativeness (71% of the Amazonian fish fauna); and low current and future vulnerability. These 2 templates, then, seemed more robust for conservation prioritization. The future of the selected sub-basins in these 2 proactive templates is not immediately threatened by human activities, and these sub-basins host the largest part of Amazonian biodiversity. They could easily be conserved if no additional threats occur between now and 2050.

Stream fish metacommunity organisation across a Neotropical ecoregion: The role of environment, anthropogenic impact and dispersal-based processes

“…Even in the Neotropics, which has a high diversity of freshwater fish [1,6], there persists a lack of studies on the distribution of aquatic organisms at large spatial scales [7]. Knowing the distribution of aquatic organisms and their structuring factors at large scale, besides providing theoretical advances, also has implications for biodiversity management and conservation [8,9,10].…”

“…However, there is currently no study using this approach on a broader scale focusing on stream fish in the Upper Paraná basin, which is one of the Brazilian ecoregions with the highest human population density and highest fish diversity. Therefore, it is vital to understand how fish assemblages are structured, in order to support political decision-making which may affect freshwater habitats within this ecorregion [53,8,10]. Additionally, by protecting fish assemblages and freshwater environments, other species are also protected [52], thereby maintaining essential ecosystem services, such as food, climate regulation and fresh water for populations living within the ecoregion [54,53].…”

A database of freshwater fish species of the Amazon Basin

“…By compiling the knowledge on the spatial distribution of freshwater fishes and addressing the taxonomic and sampling gaps, the Amazon Fish database should become a valuable and long-lasting source of information for ecological and conservation studies. The database is currently being used to analyse fish diversity patterns at the Amazon Basin scale 19 , to evaluate the potential effect of climate change 20 and fragmentation 21 on this biodiversity and to define diversity hotspots for the whole basin conservation priorities 22 . Besides improving our fundamental knowledge of the patterns and processes involved in the generation of Neotropical freshwater fish diversity, the information provided can also help developing regional conservation programs and contributing to largescale transnational ecosystem management initiatives.…”

Incorporating Established Conservation Networks into Freshwater Conservation Planning Results in More Workable Prioritizations

“…The implementation of conservation plans can present substantial challenges to practitioners as the majority of published conservation assessments do not result in conservation actions (Knight et al, 2008). Incorporating established conservation networks into the conservation planning process is gaining popularity in freshwater systems (Nel et al, 2009a;Esselman and Allan, 2011;Esselman et al, 2012;Hermoso et al, 2015a;Grantham et al, 2016;Howard et al, 2018;Linke et al, 2019;Jézéquel et al, 2020), however comparisons of these approaches to other frameworks are limited. This study expands on previous efforts by evaluating how the results derived from a prioritization which accounts for established conservation networks compares to two alternative approaches, one which does not incorporate established conservation networks (Blank slate approach) and another which relies on habitat integrity rather than species representation (Human threat index approach).…”