Threshold responses of Amazonian stream fishes to timing and extent of deforestation

Prudente B.S., Pompeu P.S., Juen L., Montag L.F.

Vitule J.R., Agostinho A.A., Azevedo-Santos V.M., Daga V.S., Darwall W.R., Fitzgerald D.B., Frehse F.A., Hoeinghaus D.J., Lima-Junior D.P., Magalhães A.L., Orsi M.L., Padial A.A., Pelicice F.M., Petrere M., Pompeu P.S., et. al.

Here we extend a discussion initiated by Toussaint et al. (Sci Rep 6:22125, 2016) concerning the relationship between global patterns of freshwater fish functional diversity (FD) and its vulnerability to human impacts. Based on a set of morphological traits, they concluded that Neotropical freshwater fishes have highest FD, but low vulnerability given high levels of functional redundancy. This conclusion implies that conservation efforts for freshwater fishes should emphasize temperate regions. This perspective is risky, because Toussaint et al.’s study seriously underestimates the full scope of FD, including important ecosystem services provided by fishes in the tropics. We briefly discuss some additional and well-documented aspects of tropical freshwater fish FD and conclude that tropical fish FD is highly vulnerable.

Muylaert R.L., Stevens R.D., Ribeiro M.C.

Understanding how animal groups respond to contemporary habitat loss and fragmentation is essential for development of strategies for species conservation. Until now, there has been no consensus about how landscape degradation affects the diversity and distribution of Neotropical bats. Some studies demonstrate population declines and species loss in impacted areas, although the magnitude and generality of these effects on bat community structure are unclear. Empirical fragmentation thresholds predict an accentuated drop in biodiversity, and species richness in particular, when less than 30% of the original amount of habitat in the landscape remains. In this study, we tested whether bat species richness demonstrates this threshold response, based on 48 sites distributed across 12 landscapes with 9-88% remaining forest in Brazilian cerrado-forest formations. We also examined the degree to which abundance was similarly affected within four different feeding guilds. The threshold value for richness, below which bat diversity declines precipitously, was estimated at 47% of remaining forest. To verify if the response of bat abundance to habitat loss differed among feeding guilds, we used a model selection approach based on Akaike's information criterion. Models accounted for the amount of riparian forest, semideciduous forest, cerrado, tree plantations, secondary forest, and the total amount of forest in the landscape. We demonstrate a nonlinear effect of the contribution of tree plantations to frugivores, and a positive effect of the amount of cerrado to nectarivores and animalivores, the groups that responded most to decreases in amount of forest. We suggest that bat assemblages in interior Atlantic Forest and cerrado regions of southeastern Brazil are impoverished, since we found lower richness and abundance of different groups in landscapes with lower amounts of forest. The relatively higher threshold value of 47% suggests that bat communities have a relatively lower resistance to habitat degradation than other animal groups. Accordingly, conservation and restoration strategies should focus on increasing the amount of native vegetation of landscapes so as to enhance species richness of bats.

Brancalion P.H., Garcia L.C., Loyola R., Rodrigues R.R., Pillar V.D., Lewinsohn T.M.

Toussaint A., Charpin N., Brosse S., Villéger S.

Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (<10%) whereas in the Nearctic and Palearctic realms, decline of the functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.

Rodrigues M.E., de Oliveira Roque F., Quintero J.M., de Castro Pena J.C., de Sousa D.C., De Marco Junior P.

Riparian zones are among the most threatened natural ecosystems, being greatly affected by land use changes across the world. Working in a savanna landscape in the Central-West region of Brazil, we assessed the responses of damselfy (Odonata) communities to changes on native vegetation extent in riparian zones. We sampled damselflies around 98 streams in a continuous gradient of native vegetation loss (0 to 100%). We used the Threshold Indicator Taxa Analysis (TITAN) to test whether the damselfly community showed nonlinear responses related to native vegetation loss within buffers of 250 m radius. We collected 1245 individuals of damselflies, representing 31 species. The TITAN identified 16 species with a significant response: 11 species with negative indicators (Z −) and five as positive indicators (Z +) in relation to native vegetation loss. Six species showed evidence of nonlinear response (Z −), at sites with native vegetation loss between 40% and 60%. We also used segmented regression analysis with species richness, which showed weak evidence of a threshold located at 54% of native vegetation loss. Differently of previous studies with other taxonomic groups in forested environments, our results indicate that the variability around the threshold is higher. Under a precaution perspective and given current levels of vegetation loss around streams where the risk of losing species is higher, we reinforce the importance of appropriate landscape management strategies. In order to effectively conserve biodiversity in aquatic-and-terrestrial environments, the native vegetation loss within pastures and agriculture landscapes, should be above the “zone of increasing risk of impact” level. According to the current Brazilian Forest Act, riparian forest of at least 30 m wide must be preserved along both sides of each watercourse. In our study 30 m vegetation wide represents only 10% of the 250 m buffer area. It implies that the current Brazilian Forest Act does not preserve the Cerrado's riparian vegetation and its associated aquatic biodiversity, since the amount of native vegetation loss is below the “zone of increasing risk of impact” we detected for damselflies in evaluated landscapes.

Uezu A., Metzger J.P.

There are few opportunities to evaluate the relative importance of landscape structure and dynamics upon biodiversity, especially in highly fragmented tropical landscapes. Conservation strategies and species risk evaluations often rely exclusively on current aspects of landscape structure, although such limited assumptions are known to be misleading when time-lag responses occur. By relating bird functional-group richness to forest patch size and isolation in ten-year intervals (1956, 1965, 1978, 1984, 1993 and 2003), we revealed that birds with different sensitivity to fragmentation display contrasting responses to landscape dynamics in the Brazilian Atlantic Forest. For non-sensitive groups, there was no time-lag in response: the recent degree of isolation best explains their variation in richness, which likely relates to these species’ flexibility to adapt to changes in landscape structure. However, for sensitive bird groups, the 1978 patch area was the best explanatory variable, providing evidence for a 25-year time-lag in response to habitat reduction. Time-lag was more likely in landscapes that encompass large patches, which can support temporarily the presence of some sensitive species, even when habitat cover is relatively low. These landscapes potentially support the most threatened populations and should be priorities for restoration efforts to avoid further species loss. Although time-lags provide an opportunity to counteract the negative consequences of fragmentation, it also reinforces the urgency of restoration actions. Fragmented landscapes will be depleted of biodiversity if landscape structure is only maintained, and not improved. The urgency of restoration action may be even higher in landscapes where habitat loss and fragmentation history is older and where no large fragment remained to act temporarily as a refuge.

Derugin V.V., Silveira J.G., Golet G.H., LeBuhn G.

A fundamental challenge in restoration ecology is to understand when species are expected to colonize newly created habitat. Determining this is important for assessing progress toward restoration goals and, more generally, for gaining insight into ecosystem functioning and dynamics. We studied this question as it relates to mid- to large-sized terrestrial fauna in restored riparian habitats at the Sacramento River National Wildlife Refuge, in northern California. We used camera traps to document use of 16 riparian corridor sites of varying restoration age. Comparisons of species richness (diversity) and visitation frequency (activity) were made across different-aged sites. We found that predator diversity and activity levels tended to be higher in restored forests than in remnant forests, and that they tended to be highest in young restored forests. This trend persisted when data from variable sampling periods were pooled, although significant differences occurred more often in wet and cold sampling periods. The trend did not always hold for the animal community at large (consisting of both predator and non-predator species). We conclude that restoration age affects predator diversity and activity levels in restored and remnant floodplain forests, and that predator communities can establish soon after restoration. Our results suggest that restoring natural river processes that promote habitat regeneration may benefit mid- to large-sized terrestrial predators that appear to mostly use early successional habitat.

Bordignon C.R., Casatti L., Pérez-Mayorga M.A., Teresa F.B., Brejão G.L.

The functional structure of communities is commonly measured by the variability in functional traits, which may demonstrate complementarity or redundancy patterns. In this study, we tested the influence of environmental variables on the functional structure of fish assemblages in Amazonian streams within a deforestation gradient. We calculated six ecomorphological traits related to habitat use from each fish species, and used them to calculate the net relatedness index (NRI) and the nearest taxon index (NTI). The set of species that used the habitat differently (complementary or overdispersed assemblages) occurred in sites with a greater proportion of forests. The set of species that used the habitat in a similar way (redundant or clustered assemblages) occurred in sites with a greater proportion of grasses in the stream banks. Therefore, the deforestation of entire watersheds, which has occurred in many Amazonian regions, may be a central factor for the functional homogenization of fish fauna.

Casatti L., Teresa F.B., Zeni J.D., Ribeiro M.D., Brejão G.L., Ceneviva-Bastos M.

In this study, we investigated the influence of environmental variables (predictor variables) on the species richness, species diversity, functional diversity, and functional redundancy (response variables) of stream fish assemblages in an agroecosystem that harbor a gradient of degradation. We hypothesized that, despite presenting high richness or diversity in some occasions, fish communities will be more functionally redundant with stream degradation. Species richness, species diversity, and functional redundancy were predicted by the percentage of grass on the banks, which is a characteristic that indicates degraded conditions, whereas the percentage of coarse substrate in the stream bottom was an important predictor of all response variables and indicates more preserved conditions. Despite being more numerous and diverse, the groups of species living in streams with an abundance of grass on the banks perform similar functions in the ecosystem. We found that riparian and watershed land use had low predictive power in comparison to the instream habitat. If there is any interest in promoting ecosystem functions and fish diversity, conservation strategies should seek to restore forests in watersheds and riparian buffers, protect instream habitats from siltation, provide wood debris, and mitigate the proliferation of grass on stream banks. Such actions will work better if they are planned together with good farming practices because these basins will continue to be used for agriculture and livestock in the future.

Ochoa-Quintero J.M., Gardner T.A., Rosa I., de Barros Ferraz S.F., Sutherland W.J.

In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land-use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000-ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with

Zeni J.O., Casatti L.

Habitat homogenization is one of the most important drivers of change in riverine fauna. Therefore, the aim of this study was to determine whether habitat homogenization influences the trophic structure of fish assemblages in tropical streams. We sampled 78 streams located in pasture and crop lands to examine habitat variables and fish. Principal coordinates analysis, canonical analysis of principal coordinates, and a distance-based test for homogeneity of multivariate dispersions revealed two groups of streams, designated homogeneous and heterogeneous, based on the habitat variables. We determined trophic guilds according to the frequency and biovolume of food items. Seven guilds were identified: aquatic insectivores, terrestrial insectivores, detritivores, herbivores, omnivores, algivores, and detritivores–algivores. Homogeneous streams showed higher abundance and biomass of aquatic insectivores, detritivores, and algivores. Heterogeneous streams showed greater diversity of trophic guilds and higher abundance and biomass of terrestrial insectivores and herbivores than homogeneous streams. Our results demonstrate that trophic structure is influenced by habitat condition. Additionally, the riparian canopy and nearshore vegetation have a modulating role in the trophic structure of stream fishes due to their influence on resource supply and promotion of the physical heterogeneity of the channel.

Casatti L., Pérez-Mayorga M.A., Carvalho F.R., Brejão G.L., Da Costa I.D.

The rio Machado (also known as Ji-Paraná) is a tributary of the rio Madeira in the Amazon basin. Currently, the rio Madeira contains the greatest fish species richness of the world, with approximately 1,000 species. The present study presents the fish inventory from streams of the rio Machado basin. In total, 75 stream reaches, 80 meter-length, randomly selected, were sampled in 2011 (August to October) and 2012 (June to July). Overall, 22,875 fish in eight orders, 32 families, 89 genera, and 140 species were collected. Richness estimators indicate that almost 90% of the expected richness was registered. The great majority of specimens (52.2%) was represented by small sized piabas such as Serrapinnus aff. notomelas, Moenkhausia collettii, Serrapinnus microdon, and Hemigrammus melanochrous. Of the total richness, 25 species were restricted to 9°00’ S and 10°00’ S; among them, 14 were exclusive to the lower portion of the basin, which exhibits the larger proportion of native vegetation covering.

Brejao G.L., Gerhard P., Zuanon J.

This study aimed to describe the functional organization of the ichthyofauna of forest streams from northeastern Pará State, Brazil, based on behavioral observation of species' feeding tactics. Seven streams were sampled between June and November, 2010, during snorkeling sessions, totaling 91h 51min of visual censuses at day, dusk, and night periods. Seventy three species distributed in six orders, 26 families and 63 genera were observed, with dominance of Characiformes, followed by Siluriformes. From information gathered by ad libitum observations, each species was included in one of 18 functional trophic groups (FTGs), according to two main characteristics: (1) its most frequently observed feeding tactic; and (2) its spatial distribution in the stream environment, considering their horizontal (margins or main channel) and vertical (water column) dimensions. The most frequent FTGs observed were Nocturnal invertebrate pickers (9 species), Diurnal channel drift feeders (8 spp.), Diurnal surface pickers (7 spp.), and Ambush and stalking predators (6 spp.). The FTGs herein defined enable a comparative analysis of the structure and composition of ichthyofauna in different basins and environmental conditions, which presents an alternative approach to the use of taxonomic structure in ecological studies. The ichthyofauna classification based in FTGs proposed in this study is compared to three other classifications, proposed by Sazima (1986), Sabino & Zuanon (1998) and Casatti et al. (2001).

Cruz B.B., Miranda L.E., Cetra M.

We hypothesised and tested a hierarchical organisation model where riparian landcover would influence bank composition and light availability, which in turn would influence instream environments and control fish assemblages. The study was conducted during the dry season in 11 headwater tributaries of the Sorocaba River in the upper Parana River Basin, south-eastern Brazil. We focused on seven environmental factors each represented by one or multiple environmental variables and seven fish functional traits each represented by two or more classes. Multivariate direct gradient analyses suggested that riparian zone landcover can be considered a higher level causal factor in a network of relations that control instream characteristics and fish assemblages. Our results provide a framework for a hierarchical conceptual model that identifies singular and collective influences of variables from different scales on each other and ultimately on different aspects related to stream fish functional composition. This conceptual model is focused on the relationships between riparian landcover and instream variables as causal factors on the organisation of stream fish assemblages. Our results can also be viewed as a model for headwater stream management in that landcover can be manipulated to influence factors such as bank composition, substrates and water quality, whereas fish assemblage composition can be used as indicators to monitor the success of such efforts.

de Paula F.R., Brejão G.L., Pérez-Mayorga M.A., Casatti L., de Barros Ferraz S.F., Krusche A.M., Krusche A.V.

Cabral G.S., da Silva R.S., Bomfim F.F., Juen L., Casatti L., Montag L., Dias-Silva K., Oliveira-Junior J.M., Michelan T.S.

Isaac V.J., Castello L., Gouveia N.A., Zuanon J.A., Martins F.A., Cruz R.E., Campos R.O., Arantes C.C., Borba G.C., Almeida M.C., Deus C.P., Dória C.R., Hauser M., Freitas C.E., Giarrizzo T., et. al.

Oliveira L.P., Fratari M.C., Silva R.S., Corrêa F., Jardim Jr A.A., Damasceno M.Y., Menezes D.S., Lopes R.E., Vieira L.J., Montag L.F.

Abstract Few studies have investigated the ichthyofauna of streams in the upper Purus River basin, hampering efforts to understand the diversity of these numerous bodies of water. This study presents the first inventory of the ichthyofauna in the upper Purus-Antimary interfluve, southwestern Amazonia. The study was based on data compiled from various sources, including online repositories, scientific articles, and fish collected from four streams in a protected area. We assessed species richness, distribution area, conservation status and anthropogenic threats. The fieldwork study was carried out in four "terra firme" streams in the Purus River basin, with fieldwork conducted during the rainy season in March and November 2017. We identified a total of 92 species, 26 families, and six orders. The order Characiformes exhibited the highest species richness with 42 species, followed by Siluriformes with 34, and Gymnotiformes with 8 species. The Characidae family was the most diverse, with 25 species, followed by Loricariidae with 11 species and Callichthyidae with seven species. The collected fish samples totaled 1,794 individuals representing 58 species, 22 families, and 4 orders. The most abundant species were Knodus smithi with 307 individuals, followed by Chrysobrycon hesperus with 247 and Tyttocharax madeirae with 165. Most species were classified as being of low conservation concern. The study expanded the known extent of occurrence for Anablepsoides hoetmeri to 2,163.777 km2. Our findings underscore the importance of conserving aquatic habitats and riparian vegetation within the upper Purus-Antimary interfluve, given the presence of a rich and restricted ichthyofauna. Furthermore, we highlight the significant risks posed by anthropogenic pressures such as deforestation for pastures, wildfires, and illegal fishing activities.

Coutant O., Lopes-Lima M., Murienne J., Pellissier L., Quartarollo G., Valentini A., Prié V., Brosse S.

Valente-Neto F., Dala-Corte R.B., Cunico A.M., Magalhães A.L., Godoy B.S., Leal C.G., Castro D.M., Macedo D.R., Lima-Junior D.P., Gubiani É.A., Roque F.D., Teresa F.B., Oliveira F.J., Becker F.G., Brejão G.L., et. al.

dos Reis Oliveira P.C., Gualda G.A., Rossi G.F., Camargo A.F., Filoso S., Brancalion P.H., Ferraz S.F.

de Lucena M.D., Ribeiro‐Martins A., Casatti L., Vieira T.B., Brejão G.L., Carvalho F.R., Michelan T.S., Juen L., de Montag L.F.

ABSTRACT The increasing environmental changes threatening the fish fauna of streams are driving a growing interest in understanding how sites and species contribute to diversity, as this is important information for decision‐making related to the management and conservation of priority areas and species. The objective of this study was to understand how environmental factors, spatial distance between streams, land use, and land cover (landscape) may be associated with the uniqueness of fish assemblages in Amazonian streams. We sampled fish assemblages and characterised environmental conditions in 29 streams within and around the Tapajós River basin, near the Amazon National Park in Brazil. Each stream was studied along a 150‐m stretch. The variables associated with the local contribution to beta diversity (LCBD) were vegetation cover and the presence of refuges. Streams inside and outside the park showed similar contributions to beta diversity. Species richness and abundance showed a negative relationship with LCBD, suggesting that unique sites tended to have few species and low abundance. The species that contributed most to beta diversity (SCBD) had intermediate occurrence, high abundance, and non‐marginal niches. We did not observe an effect of niche breadth on SCBD, as both generalist and specialist species contributed equally to beta diversity. Our findings underscore the role of environmental variables in ecological uniqueness. Sites unique in species composition may also exhibit low species richness and abundance. Our study demonstrates the importance of environmental variables in conserving biodiversity in Amazonian streams in the face of environmental changes. By examining the contributions of sites and species, we highlight the importance of considering habitat quality and uniqueness in protecting these ecosystems against the challenges of global change.

Gupta S., Vijarania P., Gupta S., Vijarania M.

Artificial intelligence is the study and design of computational models which exhibit human intelligence in performing tasks framed into computers, imitating most especially the human brain in executing a task it is set to do. It has been applied in many fields due to its potential of processing a large volume of data and has, therefore, revolutionized applications such as map-based navigation, facial detection and recognition, chatbots, and robotics. AI plays an important role in wild animal conservation with the help of advanced tools like drones, sensors, and camera based monitoring systems to keep a count on animal populations, the activities of poachers, and develop an understanding of ecosystems for the protection of endangered species and to ensure biodiversity is not threatened. risks remind us that careful research, regulation, and collaboration amongst politicians, researchers, developers, industry professionals, and civil society are needed to render AI's application responsible and ethical for the betterment of humanity with reduced harm.

Barros G.G., Mascarenhas B., Zuanon J., de Deus C.P.

Freshwater environments are among the most threatened by anthropogenic impacts in the world. Among these environments, streams are especially vulnerable to structural changes, water pollution, alterations in food chains, and loss of biodiversity, resulting from deforestation, agricultural land use, as well as small dams and road construction. Changes in rainfall patterns and increased temperature resulting from climate change may boost the negative effects of local habitat disturbances and disrupt physiological, biological and behavioral responses of the aquatic biota, including the instability of seasonal predictability. Here, we evaluate the current knowledge regarding the effects of local anthropogenic disturbances and those from ongoing planetary climate changes on the aquatic environment and fish fauna of small streams worldwide, with a special focus on Amazonian forest streams. To do so, we conducted a (non-exhaustive) literature review searching for information regarding direct and indirect impacts of climate change on the structure and hydrological dynamics of headwater streams around the world. Then, we present information on the effects of such environmental changes in species distributions, on the taxonomic and functional structure and composition of stream fish assemblages in the Amazon and in other biomes. Despite the scarcity of published references dealing with combined/synergic effects of climate change and local anthropogenic impacts on the biology and ecology of stream fishes worldwide, we bring some insights about these emerging environmental problems affecting Amazon stream fishes.

Fernando A.M., Severo‐Neto F., Ferreira F.S., Mateus L., Tondato‐Carvalho K.K., Kashiwaqui E.A., Gimenes Junior H., Domingues W.M., Pavanelli C.S., Pinho H.L., Penha J., Súarez Y.R.

AbstractLack of sufficient knowledge of biological diversity is the first barrier to promoting scientifically‐based conservation policies in Neotropical regions, where high diversity and limited sampling remains a challenge. We compiled fish occurrences data from the whole Upper Paraguay River basin (UPRB) and evaluated the altitudinal variation in species richness, local contribution to beta diversity (LCBD) and composition. We also evaluate the influence of other environmental variables on species richness. Occurrence of a total of 342 native and five exotic fish species were recorded. Fish species richness was higher in lower portions of the basin, with a clear decrease from 400 m.a.s.l. Richness was negatively correlated with altitude, and positively correlated with net primary productivity and slope. The LCBD presented higher values on floodplain and in headwaters. Intermediate classes presented greater relative importance, as they present greater relative richness in a small relative area in the basin. We observed a partial overlap in species composition along altitude classes. Three species classified in some category of threat according to the conservation status of ichthyofauna in Brazil have a limited spatial extent of occurrence, restricted within the Serra da Bodoquena plateau. The obtained results highlight the unique diversity in the floodplain–plateau continuum, therefore, choosing protected areas must consider altitude gradients in the UPRB. Given the small area of the conservation units in the basin, the important role of higher altitude streams in regional fish species diversity and the several threats in the plateau, we conclude that an increase in conservation effort is needed in the plateau portion of the Upper Paraguay River basin.

Tabi A., Santos E.P., Brejão G., Siqueira T.

AbstractLand use change affects the biodiversity of terrestrial landscapes as well as of the freshwater systems they surround, and thereby numerous ecosystem services that are essential for human well-being. Previous research suggests that freshwater systems show delayed responses to abrupt disturbances such as deforestation, however less is known about whether there is a legacy effect of landscape history on freshwater communities under a long history of land use change. We addressed this research gap here by first quantifying the historical complexity of landscapes, including natural and agricultural formations, in terms of their composition and configuration in 26 tropical catchment areas surrounding 101 streams over a 30-year period. We identified clear evidence for a memory effect of past events, whereby historical landscape complexity, measured as the information entropy of landscape composition, positively affected freshwater biodiversity. Finally, using a causal discovery approach, we showed that species richness was causally related to landscape complexity only when historical values were incorporated. Our results corroborate previous work on the positive effect of landscape complexity on biodiversity, and also confirm the role of historical contingencies in predicting future ecological outcomes.

Couto T.B., Jenkins C.N., Beveridge C.F., Heilpern S.A., Herrera‐R G.A., Piland N.C., Leal C.G., Zuanon J., Doria C.R., Montoya M., Varese M., Correa S.B., Goulding M., Anderson E.P.

AbstractDespite the importance of freshwater ecosystems to social‐ecological systems of the Amazon, conservation in the region historically has focused on terrestrial ecosystems. Moreover, current information on pressing management and conservation needs specific to freshwaters is scattered across multiple disciplines and generally focused on particular threats, habitats, and taxa. This disparateness of information limits the ability of researchers and practitioners to set priorities and implement actions that comprehensively address challenges faced by freshwater ecosystems. To reduce this research‐implementation gap, we reviewed the scientific literature on Amazon freshwater conservation to identify pressing actions to be taken and potential directions for their implementation. We identified 63 actions gleaned from 174 publications. These were classified into six major themes: (i) implement environmental flows, (ii) improve water quality, (iii) protect and restore critical habitats, (iv) manage exploitation of freshwater organisms, (v) prevent and control invasive species, and (vi) safeguard and restore freshwater connectivity. Although each action may face different implementation challenges, we propose three guiding principles to support action planning and decisions on‐the‐ground. We conclude with a reflection on potential future directions to place freshwaters into the center of policies and agreements that target the conservation of the Amazon.

Tavares B.M., Amui G.S., Silva V., Pereira T.N., Pelicice F.M., Brancalion P.H., Chamon C.C., Azevedo-Santos V.M.

The presence of livestock in riparian areas raises several questions about the conservation and sustainable use of water resources and biodiversity in Brazil. Although the Native Vegetation Protection Law (No. 12,651) focuses on riparian vegetation, protected as Permanent Preservation Areas (APPs), it does not exclude the presence of livestock in these fragile areas. Here, we provide an overview of APPs in Brazil and analyze the legal instruments that enable livestock in these areas, gathering the scientific evidence on associated environmental impacts. Currently, cattle in riparian areas represent a direct threat to biodiversity and ecosystem functioning and services, especially because these animals promote trampling, loss of vegetation, soil erosion, siltation, and pollution through urine and feces. To avoid cattle in APPs, legislation should be revised to implement more stringent restrictions; in parallel, alternatives for watering the animals must be sought, such as, for example, the installation of artificial ponds and drinking fountains. It would be appropriate to propose legislation or create incentives to fence livestock in pasture areas to preventing it from accessing APPs. Increasing cattle confinement is an alternative measure to traditional ranching in open pasture. Riparian zones represent a critical environment for biodiversity and society, so the presence of cattle and its associated negative impacts should be seriously considered by authorities.

Barbosa T.A., Prudente B.D., Mendonça M.B., Salvador G.N., Montag L.F., Akama A.

Abstract Aim Considering the importance of knowing the organisms that make up the environments impacted by human activities, we aimed to create an inventory of the ichthyofauna of a bauxite mining area in the Eastern Amazon in this work. Methods Specimens were collected with sieves, trawls, and gill nets at 37 points in rivers and streams during two expeditions (July 2017 and September and October 2017). After euthanasia and laboratory processes, we identified each individual to the lowest possible taxonomic level, and samples were deposited in scientific collections. We analyzed the conservation status of the species on state, national, and international lists. Results A total of 109 species were identified, belonging to 28 families and six orders, emphasizing the Characiformes order (57 species) and the Characidae family (22 species). We identified two new species, and none are threatened with extinction. Conclusions The high species richness recorded in the Potiritá River basin is noteworthy, considering its relatively small area. This diversity should be considered in future environmental impact studies and in monitoring the ichthyofauna in areas affected by human activities.