Stream Fish Diversity Research Articles

Aquaculture activities associated with the invasion of Oreochromis niloticus and changes in stream fish diversity

Aquaculture activities associated with the invasion of Oreochromis niloticus and changes in stream fish diversity

Scale effects of riparian forests on fish diversity in streams of the upper Paraná River basin

Scale effects of riparian forests on fish diversity in streams of the upper Paraná River basin

Local environment and fragmentation by drought and damming shape different components of native and non-native fish beta diversity across pool refuges

Pool refuges are critical for maintaining stream fish diversity in increasingly intermittent streams. Yet, the patterns and drivers of beta diversity of native and non-native fish in pool refuges remain poorly known. Focusing on Mediterranean streams, we decomposed beta diversity of native and non-native fish into richness difference (RichDiff) and species replacement (Repl), and local (LCBD, LCBDRichDiff and LCBDRepl) and species (SCBD) contributions. We assessed the influence of environmental and spatial factors associated with drought and damming fragmentations on beta diversity components and LCBDs, and of local species richness and occupancy on LCBDs and SCBD, respectively. Overall, non-native species showed a more limited occupancy of pool refuges than native fish. RichDiff dominated beta diversity, though it was influenced by drought and damming fragmentations for native fish and local environment for non-native fish. Repl for native fish was slightly influenced by local environment, but for non-native fish was largely driven by drought and damming, albeit with a contribution of local environment as well. LCBD and LCBDRichDiff increased in pools in low order streams for native fish and at low elevations for non-native fish, and with high or low species richness. SCBD was higher for native species with intermediated pool occupancy, but for non-native species with low occupancy. Our results suggest that stream fragmentation may drive native species loss and non-native species replacement in pool refuges, and that environmental filtering may shape non-native species loss. Pools in lower order streams harbouring unique species-rich or species-poor assemblages should be prioritize for conservation and restoration, respectively, and pools at low elevation with unique non-native assemblages should deserve control efforts. We encourage the partitioning of beta diversity and individual analysis of native and non-native fish in intermittent streams, which may be key in stressing the importance of pool refuges in safeguarding native fish diversity.

Multiscale analysis predicts native species presence based on habitat and nonnative species abundance

AbstractObjectiveThe loss and degradation of aquatic habitat through fragmentation, water extraction, and climate warming contribute to declining native stream fish diversity. In response to these declines, a large‐scale repatriation program was established in Arizona and New Mexico to expand the distribution and abundance of native fishes. This program has had variable success, with imperiled fish populations establishing and persisting in some streams, while other populations failed to establish.MethodsTo identify factors contributing to the success of repatriation, we conducted a study investigating how biotic and abiotic variables affect native fish presence or absence at differing spatial scales throughout the Gila River basin. We conducted fish and habitat surveys in 29 river reaches at three spatial scales: the 1‐km, 0.1‐km, and mesohabitat scale. We used generalized linear models to identify associations among species presence, habitat characteristics, and nonnative species abundance across spatial scales. Logistic regression models were also used to test associations with heterogeneity of habitat characteristics and species presence.ResultModels indicated strong species‐ and scale‐specific responses to these variables. Nonnative abundance was less influential than other habitat variables in predicting the presence of native fish, although the majority of associations that emerged were negative. Further, we were able to identify that water velocity, depth, and substrate size were the most common variables associated with species' presence across all scales and age‐classes, with most species responding positively to elevated velocities and variable responses for depth and substrate size. Response to variation in habitat was species‐specific, with some associations positive and others negative.ConclusionCollectively, the information from this study will help identify locations with a reasonably high likelihood of supporting native fishes and broaden our understanding of species responses to habitat and nonnative species across multiple scales.

Impact of Dams on Stream Fish Diversity: A Different Result

Impoundments can drastically change the physical and biological characteristics of fluvial systems. Changes in the physical characteristics, such as reductions in flow, increased sediment deposition, and increased surface area, often influence the system’s biological components, including plant, macroinvertebrate, and fish assemblages. In addition to having direct effects on impounded waterbodies, impoundments can also have wide-ranging effects at the watershed scale, particularly on upstream tributary streams. The purpose of this study was to assess the magnitude of these effects. We analyzed historical data from 26 streams distributed across five sub-basins in the Bluff Hills region of the Yazoo Basin, MS, USA. All five major tributary rivers in this region are impounded by large (11,240–26,143 hectares) reservoirs for flood control. We compared fish assemblages in streams located upstream and downstream of the four reservoirs using PERMANOVA, and contrary to expectations, we found no significant differences between the upstream and downstream assemblages. We explore several possible explanations for this discrepancy and suggest that stream assemblage response to impoundment may be nuanced by the regional species pool, the history of stream conditions in the watershed, and the resistance of the streams to periodic disturbances.

Species richness of mussel assemblages and trait guilds in relation to environment and fish diversity in streams of Illinois, the USA

Species richness of mussel assemblages and trait guilds in relation to environment and fish diversity in streams of Illinois, the USA

Effects of land use on the β‐diversity of fish assemblages in subtropical headwater streams, China

AbstractLand use related to human activities poses a serious threat to aquatic ecosystems and biodiversity, especially in headwater streams. However, uncertainty about how land use affects stream fish diversity may be detrimental to practising effective conservation. This study investigated two neighbouring headwater streams of similar size with different surrounding land use intensities (the less‐disturbed Shuxi Stream and the heavily disturbed Maxi Stream) of the Qingyi River in China. We assessed the effects of land use on the β‐diversity of stream fishes by comparing the fish assemblages in the two streams. The results showed that the Maxi Stream displayed higher habitat and assemblage structure heterogeneities than the Shuxi Stream. Taxonomic and functional β‐diversities were significantly higher in the Maxi Stream than in the Shuxi Stream, possibly due to the greater spatial autocorrelation and agricultural land use intensity in the Maxi Stream. Neither urban nor garden land use nor habitat conditions were associated with β‐diversity owing to the low corresponding land use intensities and the lack of hydrochemical measurements. Our results suggest that land use types adjacent to streams directly affect habitat conditions and fish diversity. Protection and recovery of riparian zones may mitigate the effects of agriculture on fish assemblage structures in subtropical headwater streams.

Protected areas and compositional diversity of fish from Serranias Costeiras of the Ribeira de Iguape River basin, Southeast Brazil

Abstract The Serranias Costeiras of the Ribeira de Iguape River basin comprise landscapes with steep slopes, where many streams are contained in protected areas. We evaluated the importance of these protected areas for stream fish diversity. We sampled the ichthyofauna during the dry season of 2010, 2018 and 2019 in 36 stream stretches. We used beta diversity measures and estimated species richness and dark diversity in streams from two types of protected areas (full protection, FP and sustainable use, SU) and outside (Out). The altitude-width and velocity gradient of the streams explained the species turnover. The PA type promoted the richness difference, with FP streams having less species richness than SU and outside. Streams from FP presented lower species richness and dark diversity. These results indicate that the few species in FPs are well protected. The FP streams contain a relevant proportion of the regional species pool and, therefore, are essential for conserving fish stream diversity in the study region. On the other hand, streams from SU or Out have higher species richness, but their fish fauna is more vulnerable. Due to longitudinal stream connectivity, we highlight the importance of rethinking the limits of protected areas.

AVALIAÇÃO DA INTEGRIDADE BIÓTICA DE RIACHOS A PARTIR DA ICTIOFAUNA

Almost four decades ago, ecologist James R. Karr published the first version of the Index of Biotic Integrity (IBI) to assess the health of aquatic ecosystems from fish assemblages. Since then, numerous adaptations, criticisms, and reinterpretations have emerged from this seminal study, covering diverse world biomes. In Brazil, the first versions of IBI for streams were developed in the South (in 2004). Over time, scientific production on this topic has shown a significant increase in the complexity of the approaches and methods used, mainly due to the advance in the basic knowledge about stream fish diversity, ecology, and biology. These studies include, for example, tests of metrics already proposed, proposals for new metrics, adaptations for different basins, and tests of the ecological responses of the ichthyofauna to different human-originated impacts. Even so, there are no standardized protocols for defining the metrics, nor for the introduction of these indexes in the stream monitoring routine. The objective of this article is to present a theoretical framework on the development of IBI for Brazilian streams, based on ichthyofauna, to discuss whether it is possible and feasible to standardize protocols for the development of IBIs and the prospects of applicability in Brazilian streams.

ECOLOGIA FILOGENÉTICA DE COMUNIDADES DE PEIXES DE RIACHO NEOTROPICAIS

Neotropical stream fishes exhibit a complex evolutionary history and encompass both old and recent lineages. Patterns of species diversity of stream fishes are relatively well-studied for Neotropical streams, but not for patterns of clade distribution and historical factors that structure these assemblages, which are the main interests of phylogenetic ecology. Understanding the evolutionary context of communities provides important insights into large-scale mechanisms that structure them. This review aims to: (i) discuss the main concepts of phylogenetic ecology and its application to Neotropical stream fishes; and (ii) highlight the main methods applied in this background. The first section presents the main phylogenetic hypothesis of fishes and discusses how their gaps in Neotropical stream fishes hinder phylogenetic ecology. Afterward, we discuss the main concepts of phylogenetic ecology (phylogenetic signal, community phylogenetic structure, and phylogenetic diversity), as well as gaps and potential applications of these concepts and tools to understand Neotropical stream fish assemblages. The second section introduces the main methods to address the phylogenetic ecology, including a standardized procedure to edit fish phylogenetic trees, comparative methods, and indices and analytical tools to understand community structure and conservation importance. Finally, we discuss the perspectives to the next years to better understand the Neotropical stream fish assemblages in the light of past and current historical processes.

The use of an integrative approach to improve accuracy of species identification and detection of new species in studies of stream fish diversity

In this study, we made an inventory of the stream and headwater ichthyofauna of the left bank of the Itaipu Dam Reservoir, located in the lower part of the Upper Paraná River basin, using an integrative approach of molecular and morphological data. The area is located in the western portion of the Paraná state in Brazil, in an area of about 8,000 km2 highly impacted by deforestation and intensive agriculture. For taxonomic identification of species, we used an identification key combined with the DNA barcoding approach. We found 48 species belonging to six orders, 13 families, and 37 genera. The Siluriformes and Characiformes were the most representative orders (75%) and the Characidae was the most representative family (20.8%). Nine species prevailed in this region, making up to 86% of all specimens collected. The integrative approach proved to be useful by allowing the unambiguous identification of all species, including those cases in which morphological characters were not conclusive for species identification, cases of cryptic species, and species with high morphological plasticity. In addition, the integrative approach highlighted six to 13 new putative species depending on the approach considered. Our study provides a relevant contribution to the knowledge of fish diversity in a poorly studied area of the Paraná River basin. We showed that the use of an integrative approach in inventory studies improves species identification and the discovery of new, cryptic, and overlooked species, being a powerful and necessary tool to quantify biodiversity.

Assessing the effects of multiple land uses on the functional beta diversity of stream fishes in the Amazon region

Large-scale deforestation not only modifies the landscape, but also affects in the structure of the habitat, and threaten the functional structure of the aquatic biota. This study evaluates the partitioning of the functional beta diversity of stream fish along a gradient of environmental impact and determines which functional traits are associated with the gradient. Biological, environmental, and landscape variables were sampled in 2014 and 2015. The functional structure of the fish fauna was characterized using 12 functional traits. The functional beta diversity and functional replacement were influenced by changes in local abiotic and landscape conditions, caused by modifications in forest cover, with the functional traits varying systematically in accordance with environmental features. We found no association between environmental variables and functional traits. Our results raise concerns with regard to the transformation of the landscapes in which streams are found caused by changes in land use, and we would recommend the preservation of an adequate buffer of good quality riparian vegetation in management or restoration projects to guarantee the long-term conservation of stream ecosystems.

Anthropogenic disturbances affect the functional diversity of stream fishes and its longitudinal patterns in China

Anthropogenic disturbances affect the functional diversity of stream fishes and its longitudinal patterns in China

Disentangling effects of predators and landscape factors as drivers of stream fish community structure

Abstract Experimental and fine‐scale studies indicate predators can have strong effects on stream fishes. It is unclear, however, how predators interact with landscape factors to influence stream fish communities at scales relevant to management and conservation. Because predators and prey respond to environmental variability, measuring community responses to predators requires resolving the effects of abiotic factors on both predators and prey. We collected stream fish community data in the summers of 2017 and 2018 and paired structural equation modelling with multivariate methods to identify abiotic factors that influenced the distribution of a predatory fish, largemouth bass (Micropterus salmoides) and community structure of stream fish. We then compared how fish species richness and community composition responded to the presence of bass mediated by environmental factors. Probability of occurrence of bass increased with catchment area, while richness responded to both natural and anthropogenic characteristics of streams and their catchments. Contrary to our prediction, richness was higher at sites with bass and several species exhibited positive co‐occurrence and abundance patterns with bass, while only one species had a negative relationship. Higher diversity of stream fishes in the presence of bass highlights the difficulties in understanding the combined effects of predators and environmental variation, both natural and human induced, as drivers of community structure. We discuss several challenges to understanding the effects of predators in natural systems, including unmeasured environmental variability, mismatch of spatial and temporal scales, and context dependency of ecological responses.

Fish diversity in streams/rivers of Kalakad-Mundanthurai Tiger Reserve, Tamil Nadu, India

This article describes fish diversity in streams and rivers of Kalakad-Mundanthurai Tiger Reserve (KMTR), Tamil Nadu. Fifty species of fishes belonging to 10 orders, 15 families, and 32 genera are recorded. Seven species, Garra joshuai, G. kalakadensis, Haludaria kannikattiensis, Hypselobarbus tamiraparaniei Mesonemachilus tambraparniensis, Neolissochilus tamiraparaniensis, and Dawkinsia tambraparniei are strictly endemic to this protected area. The minnows, Devario aequipinnatus, Garra mullya, and G. kalakadensis are widely distributed in KMTR streams. High species diversity (H’=2.81) was recorded in Gadana River, whereas low species diversity (H’=0.61) was registered in Poonkulam area. Bray-Curtis similarity analysis showed that sites along the headwater streams have similar faunal assemblage. Result of regression analysis revealed that there is a significant pattern explained between stream order and species richness (r2=0.86; p<0.05). Among 50 species, four (Garra kalakadensis, G. joshuai, Dawkinsia tambraparniei, and Tor malabaricus) are listed in threatened categories of IUCN Red List. Important threats faced by endemic species and their management strategies are discussed.

Geology‐dependent impacts of forest conversion on stream fish diversity

Forest conversion is one of the greatest global threats to biodiversity, and land-use change and subsequent biodiversity declines sometimes occur over a variety of underlying geologies. However, how forest conversion and underlying geology interact to alter biodiversity is underappreciated, although spatial variability in geology is considered an integral part of sustaining ecosystems. We aimed to examine the effects of forest conversion to farmland, the underlying geology, and their interaction on the stream fishes' diversity, evenness, and abundance in northeastern Japan. We disentangled complex pathways between abiotic and biotic factors with structural equation modeling. Species diversity of stream fishes was indirectly shaped by the interaction of land use and underlying geology. Diversity declined due to nutrient enrichment associated with farmlands, which was mainly the result of changes in evenness rather than by changes in species richness. This impact was strongest in streams with volcanic geology with coarse substrates probably because of the differential responses of abundant stream fishes to nutrient enrichment (i.e., dominance) and the high dependency of these fishes on large streambed materials during their life cycles. Our findings suggest that remediation of deforested or degraded forest landscapes would be more efficient if the interaction between land use and underlying geology was considered. For example, the negative impacts of farmland on evenness were larger in streams with volcanic geology than in other stream types, suggesting that riparian forest restoration along such streams would efficiently provide restoration benefits to stream fishes. Our results also suggest that land clearing around such streams should be avoided to conserve species evenness of stream fishes.

Taxonomic and functional diversity in a subtropical stream: A longitudinal pattern analysis

AbstractIdentifying the spatial patterns of fish diversity in streams is basic for the conservation and management of stream fishes. The “upstream–downstream” patterns in the taxonomic α‐diversity of stream fishes have been widely surveyed. However, the longitudinal patterns in the functional diversity and β‐diversity of stream fishes have been given less attention. In this study, we surveyed fishes along an upstream–downstream gradient in a headwater stream of the Qiantang River, China, and examined the longitudinal variations in fish diversity. Our aims were to assess whether the longitudinal patterns in fish diversity were consistent between the taxonomic and functional metrics and between the α‐ and β‐aspects of diversity. We found that both species richness and functional richness of fishes showed a hump‐shaped relationship with the distance from headwaters, while both taxonomic and functional β‐diversities presented the U‐shaped distributions along the river continuum. Functional diversity related more to the distance from headwaters than taxonomic diversity. Despite their similar relationship with the distance from headwaters, taxonomic and functional β‐diversities were dominated by species turnover and function nestedness components, respectively. Our results suggest that, along the river continuum in a subtropical stream, the α‐ and β‐aspects of fish diversity present different longitudinal variations. Although the taxonomic and functional diversity shows similar relationships with distance from headwaters, their spatial variations are driven by different ecological processes.

Microgeographic Variation and Inter-Riffle Migration of <i>Rhinichthys atratulus</i> (Pisces: Cyprinidae) in a Small Connecticut Stream, United States

We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.

Distance to large rivers affects fish diversity patterns in highly dynamic streams of Central Amazonia.

Longitudinal-zonation hypotheses generally predict gradual changes in fish composition from upstream to downstream due to changes in habitat conditions, but largely disregard downstream effects on upstream segments. Floodplains of large rivers represent areas of high connectivity during flood periods and can act as stable refuges in dry seasons, which may attenuate deterministic constraints imposed by local conditions on fish assemblages in surrounding habitats. In this study, we investigated the effects of proximity to large rivers on taxonomic- and functional-diversity patterns of stream-fish assemblages in an extensive region of Central Amazonia. We sampled 31 headwater-stream reaches in nine catchments in the Purus and Madeira Rivers interfluve between December 2014 and March 2015. Ninety seven fish species from seven orders and 19 families were captured. The results indicate that distance to large rivers is more important than distance among sites and local conditions in explaining functional and taxonomic diversity of stream-fish assemblages at large spatial scales. We also found a decrease in taxonomic and functional richness towards headwaters, mainly related to the loss of benthic and sedentary species along the distance gradient. These species may be favored by the proximity to refuge areas and high resource availability near the floodplain. In contrast, upstream assemblages were mainly occupied by small-sized, nektonic species with higher dispersal capacity, highly dependent of allochthonous resources. Downstream effects could be detected for many kilometers upstream in hydrographic catchments and this reinforces the crucial role of connectivity between fluvial habitats in maintenance of stream-fish diversity patterns in the region.

If you build it, they will go: A case study of stream fish diversity loss in an urbanizing riverscape

Abstract Stream fish diversity is threatened by anthropogenic environmental alterations to landscapes, and successful conservation requires knowledge of the processes that degrade diversity. A primary step in identifying diversity losses is the comparison between historical and contemporary states of landscapes and fish assemblages, but uncertainty remains regarding the appropriate spatial scales of investigation. Historical data collected in 1976 were paired with two years of contemporary replication (2015, 2016) to assess fish diversity change at 10 sites in Blackburn Fork, TN, USA. Analyses focused on a nested hierarchy of spatial scales, including sampling sites (fine scale), nested within stream orders (intermediate scale), nested within the entire catchment (broad scale). Diversity change between 1976 and 2015–16 was assessed using traditional diversity metrics (site scale) and rarefaction (stream‐order scale), whereas spatial variation in contemporary diversity (2015–16) was assessed with nonmetric multidimensional scaling (catchment scale). At the site scale, locations on the east side of Blackburn Fork and in close proximity to developed land experienced diversity loss. At the stream‐order scale, the effective number of species declined in first‐order streams where land development was concentrated, but no consistent species losses occurred in other stream orders. At the catchment scale, assemblages responded significantly to stream size but not land use, perhaps because diversity was already homogenized by 2015–16. Mapping 40 years of land‐use change across the catchment underscored a pattern of spatial alignment between developed lands and stream fish diversity loss. This study highlights the benefits of considering multiple spatial scales when assessing historical change in stream fish assemblages, and highlights stronger inference derived from historical comparisons relative to contemporary space‐for‐time substitutions. This framework combines recent analytical advances in rarefaction with a riverscape perspective, and can be applied to conserve streams, and their biota, in riverscapes around the world.