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Luciana L. Santos Naraiana L. Benone Bruno E. Soares Ronaldo B. Barthem Luciano F. A. Montag 《Ecology of Freshwater Fish》2019,28(3):424-433
Studies of trait–environment relationships provide important tools for the prediction of the response of biological communities to environmental alterations. The Amazon basin presents enormous potential for the development of research on this type of relationship, given the diversity of both its fish fauna and the aquatic ecosystems this fauna inhabits. The present study investigated the association between local environmental variables and the functional traits of fish in 54 streams of six major Amazonian basins. We identified the relationship between the characteristics of the streams (channel morphology, channel habitat units, riparian vegetation cover, large woody fragments and instream cover for aquatic organisms) and fish traits related to locomotion, habitat use and feeding behaviour. The fish fauna of the broader, deeper and more slowly flowing streams was dominated by nektobenthic species that exploit autochthonous resources such as fish and invertebrates. In narrow, fast‐flowing streams, by contrast, there was a predominance of benthic fishes with varying feeding habits, including periphytivorous and invertivorous species. Narrow, shady streams were inhabited by nektonic species adapted for the exploitation of resources from the marginal vegetation. The results of this study contribute to the understanding of the association between the functional structure of fish assemblages and local environmental variables in Amazonian streams. We hope that these findings will stimulate further research into the natural variation in stream fish assemblages that will ensure the development of more effective management strategies that better protect these important aquatic ecosystems. 相似文献
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David Tickner Patrick D. Armitage Melanie A. Bickerton Kevin A. Hall 《水产资源保护:海洋与淡水生态系统》2000,10(3):179-196
1. The purpose of this paper is to demonstrate: (i) how mesohabitats—medium‐scale habitats which arise through the interactions of hydrological and geomorphological forces—can be used as a basis for assessing instream habitat diversity; (ii) how combining data on mesohabitat distribution with those from macroinvertebrate sampling can produce an index for assessing stream quality; and (iii) how, when nested with River Habitat Survey (RHS), mesohabitat information can provide a comprehensive assessment of stream quality. 2. A survey of a small chalk stream in southern England showed that the distribution of mesohabitats varied considerably between reaches. However, a mesohabitat quality index, derived from data on mesohabitat distribution and faunal communities, indicated that there was relatively little longitudinal variation in stream quality as defined by mesohabitat diversity and macroinvertebrate community. Heavy modification of the channel banks, as indicated by RHS, suggested significant habitat impoverishment. 3. Simulations, using different environmental conditions, suggested that the mesohabitat quality index was a potentially useful measure of stream quality. 4. The combination of mesohabitat survey and RHS provided a more comprehensive view of the stream channel and banks than either technique used alone. The study indicated that management efforts to rehabilitate impoverished reaches should be directed towards maximizing instream mesohabitat diversity and mitigating human impacts on the river margin. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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Fish trait diversity in littorals of two floodplain lakes of the highly biodiverse Caura River,Venezuela 
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下载免费PDF全文 We studied the trait diversity and structure in the fish communities of two floodplain lakes of the Caura River: Aricagua and Paramuto, during one hydrological cycle. We calculated taxonomic and a functional alpha and beta diversities and made comparisons among hydrological seasons and among habitats within each lake based on rarefactions. The trait structure was explored with an RLQ (analysis of a table R of environmental conditions, a table L of abundances of species and a table Q of species traits) analysis, and pairwise relationships between environmental variables and traits were explored with fourth‐corner analyses. Despite its smaller extension, Paramuto showed higher alpha taxonomic and trait diversities. The substrates of open sand and those covered by leaf litter were the most diverse habitats in terms of both species and traits. The trait structure of the fish communities was influenced by the hydrological seasons, the lakes as well as water pH and temperature, and in a lesser degree dissolved oxygen, habitat type and total dissolved solids in the water. These factors constitute the habitat templet for the fish community's composition and trait structure. 相似文献
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Habitat specialization and sensitivity to change in a threatened crayfish occupying upland streams 下载免费PDF全文
下载免费PDF全文 1. Crayfish are culturally and ecologically important species in freshwater ecosystems, but many are now threatened with extinction, due to threats such as habitat loss. Depending on their habitat selectivity and sensitivity, freshwater crayfish could provide effective targets for stream monitoring, restoration and conservation. This study used repeated field surveys of the threatened Murray crayfish, Euastacus armatus (family Parastacidae), to establish their habitat preferences and sensitivity to habitat loss across mesohabitat and microhabitat scales within upland streams of south‐east Australia. 2. Selectivity analysis revealed that upland populations of E. armatus displayed a strong preference for areas of intermediate water flow velocity, deeper water, and stream beds dominated by boulders and gravel. Variations in E. armatus density among and within the two upland streams aligned with these microhabitat preferences, with best‐subsets analyses revealing that E. armatus abundance hotspots were best predicted by models combining water depth with percentage cover of boulders, gravel and overhanging riparian vegetation. 3. Major shifts in stream habitat condition from 2009 to 2015 (e.g. 32% and 50% decline in boulder and overhanging vegetation cover, respectively) was associated with a 91% decline in E. armatus mean density within glide‐pool mesohabitats. 4. These findings highlight how habitat specialization in threatened crayfish such as E. armatus may render them sensitive to changes in stream habitat condition, and how targeted monitoring, restoration and conservation of their preferred habitats could yield multiple benefits for montane freshwater ecosystems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Montaña CG, Winemiller KO. Local‐scale habitat influences morphological diversity of species assemblages of cichlid fishes in a tropical floodplain river.Ecology of Freshwater Fish 2010: 19: 216–227. © 2010 John Wiley & Sons A/S Abstract – We examined the taxonomic and morphological diversity of cichlid fish assemblages in a floodplain river in Venezuela during the dry season at two spatial scales: macrohabitats (lagoons, main channels and creeks) and mesohabitats (leaf litter, sand banks, rocky shoals and woody debris). Nonmetric multidimensional scaling did not reveal differences for species assemblages among macro and mesohabitats. The first two axes from canonical correspondence analysis based on 19 species and six physical variables modelled >61% of the taxonomic variation in assemblages from rock shoals and woody debris, and 55% of variation in assemblages from sand banks and leaf litter. Principal components analysis based on 22 morphological variables yielded two dominant axes that explained >86% of variation in the cichlid assemblages. Morphological diversity was analysed to test the idea that assemblage structure is nonrandom, with structurally complex habitats supporting more species with more functional morphological diversity than simple habitats. Average and standard deviation (SD) of the morphological Euclidean distances of local assemblages among mesohabitats tended to decrease or be constant as the number of species increased. Regressions of the average nearest neighbour distance (NND) and SD of NND with species richness resulted in low and negative slopes of species assemblages among mesohabitats. These relationships suggest that when more species are added to a habitat patch, assemblage morphospace remains approximately constant, species average similarity increases and species dispersion in morphological space becomes more uniform. Results support that cichlids partition habitat at the local scale but not at the macrohabitat scale. 相似文献
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Jose Luis Poveda-Cuellar Edwin Orlando Lpez Delgado Pamela Tatiana Zúiga-Upegui Francisco Antonio Villa Navarro 《Ecology of Freshwater Fish》2022,31(1):87-101
Understanding the mechanisms that structure communities have been a major challenge in ecological theory. Functional trait-based approaches are increasingly used for studying the processes underlying community assembly. However, species-poor systems of Andean streams these processes are largely unknown. Tropical Andean streams are highly variable in space-time and characterised by the harsh or stable environment, resulting in a high taxonomic and ecological diversity. In this study, we tested the influence of environmental variables on the fish functional structure. We proposed that in ecosystems with harsh environments, environmental filtering will structure fish assemblages, and in ecosystems with a more stable environment, limiting similarity will prevail, increasing functional diversity. We analysed fish assemblages using functional diversity indices, fourth-corner RLQ analyses and multiple regression models. Environmental variables such as altitude, stream width, sub-Andean vegetation and pH influenced functional diversity. For instance, high values of functional redundancy were registered at high elevation streams, reflecting fish assemblages composed of highly dominant species with similar functional traits such as species of the genus Astroblepus. However, we found differences between Astroblepus species in the number and distance of gill rakers which might indicate resource partitioning and coexistence. On the other hand, our results show both stochastic dynamics and environmental filtering are structuring fish assemblages in low and high elevation Andean streams respectively. 相似文献
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Jordan M. Holcomb Robert B. Nichols Michael M. Gangloff 《Ecology of Freshwater Fish》2016,25(4):553-564
Low‐head dams are ubiquitous in eastern North America, and small dam removal projects seek to improve habitat conditions for resident and migratory fishes. Effects of small dams of varying status on local fish communities are poorly documented, and recent work suggests benefits of maintaining fragmentation. We sampled fish at 25 dams (9 breached, 7 relict, 9 intact) in three river basins in North Carolina, USA. Fishes were sampled at three reaches/dam from 2010 to 2011. Study reaches were located upstream (free‐flowing reaches), downstream (tailrace) and >500 m downstream of dams (n = 75 reaches). Analyses revealed significantly elevated fish CPUE, taxa richness and percentage intolerant taxa in intact dam tailraces suggesting small dams may improve conditions for resident taxa. Breached dam tailrace reaches exhibited lower fish CPUE, taxa richness and percentage intolerant taxa relative to upstream reference reaches. Relict dams exhibited no between‐reach differences in fish community metrics. Nonmetric multidimensional scaling revealed drainage‐specific stream fish responses across study drainages. Tar and Roanoke drainage streams with intact and relict dams supported fish assemblages indicative of natural communities, whereas Neuse Drainage streams with intact and breached dams contained disturbed habitats and communities. These data demonstrate fish community responses to dam condition are drainage specific but communities in streams with intact and relict dams are largely similar. Additionally, breached dams may warrant higher removal priorities than intact dams because they negatively influence fish communities. The variability in response to some dams indicates managers, regardless of region or country, should consider holistic approaches to dam removals on a case‐by‐case basis. 相似文献
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Environmental and spatial processes: what controls the functional structure of fish assemblages in tropical rivers and headwater streams? 下载免费PDF全文
下载免费PDF全文 In this study, we investigated functional structure patterns of tropical headwater and river fish assemblages. We hypothesised that environmental conditions are primarily structuring headwater streams leading to functionally clustered assemblages, whereas processes that favour functional overdispersion would guide river assemblages. For 27 headwater streams and 22 rivers, we used eight functional traits for calculating two functional indexes: mean pairwise distance (MPD) and net relatedness index (NRI). We performed linear regressions between indexes and species richness, a multiple regression between NRI and eight environmental variables and a variation partitioning to disentangle the role of environment and space on NRI. Our findings indicate that fish assemblages of headwaters are structured by environmental conditions as most assemblages in this habitat displayed a tendency to clustering and MPD/NRI were not correlated with species diversity, whereas the opposite pattern was observed for river habitat. Four environmental variables (channel depth, water velocity, dissolved oxygen and turbidity) explain 56% of functional structure variation. These variables seem to function as selective filters in headwaters, whereas channel depth may be determinant for functional overdispersion of river fish assemblages. Components associated with space are also influencing the functional structure. Limitations of species dispersal through space (between both habitat types) appear as a possible cause to this. In this sense, both environmental conditions and processes linked with space are capable of influencing the functional structure of tropical headwater streams and river fish assemblages. 相似文献
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- 1. A classification scheme for ecohydraulic‐based mesohabitat units was developed for a summer low‐flow period. Mesohabitat unit designations were based on the integration of three‐dimensional channel hydraulics, geomorphic maintenance processes of bed morphology, and biological resource needs of fish. Ecological relevance of the units was evaluated by a study of fish mesohabitat use patterns, and species relationships to feeding guild. By portraying the stream as a mosaic of hydraulic habitat patches that provide specific biotic resource needs, this study's aim was to advance how ecological information may be incorporated into the stream restoration design process.
- 2. Nine mesohabitat units were designated, including pool‐front, ‐mid, and ‐rear units, scour pool, simple and complex riffles, glide, submerged point bar, and channel expansion marginal deadwater. Physical habitat structure differed among the nine mesohabitat units by length, water depth, and bed slope and complexity. Fish were collected in specific unit volumes by use of prepositioned areal electrofishing devices, in which distinct patterns of fish mesohabitat use were observed.
- 3. A key finding was the differences in fish assemblages among the pool units, in which fish densities were greatest in the pool‐front and scour pool units. Also, fish density in the pool‐front unit was positively correlated with pool entrance slope. Biomass was greatest in the pool‐front and ‐mid units, and it was correlated with maximum mid‐pool depth. Density and biomass were generally lowest in the pool‐rear unit. Other unique relationships were also observed among the mesohabitat units.
- 4. Based on feeding guild, patterns of fish mesohabitat use were observed for this summer low‐flow period; insectivores dominantly used pool‐front and scour pool units, herbivores dominantly used complex riffle units, and piscivores used pool‐front and ‐mid units.
- 5. Useful ecological information was derived from fish species‐habitat relationships observed in this study, linking mesohabitat units with species requirements for food resources. Such findings support advancements to ecological design strategies for stream restoration that promote hydraulic habitat diversity.
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Taxonomic versus functional diversity metrics: how do fish communities respond to anthropogenic stressors in reservoirs? 下载免费PDF全文
下载免费PDF全文 Biological indicators are frequently used to assess the effects of anthropogenic stressors on freshwater ecosystems. The structure of fish communities and their response to stressors have been commonly described by taxonomic richness, diversity and evenness. More recently, functional structure of communities has also been suggested to be a reliable indicator of disturbance. This article aimed at testing whether taxonomic and functional diversity metrics can provide comparable or complementary information on the response of fish communities to eutrophication and abundance of non‐native species in reservoirs. Comparison of the responses of taxonomic and functional diversities to biogeography, habitat and stressors was made in 112 French reservoirs. Widely observed effects of biogeographic and habitat variables on taxonomic and functional diversities were identified. Taxonomic and functional richness metrics notably increased with lake area and temperature respectively. Taxonomic diversity metrics did not respond to any stressor, while all functional diversity metrics were found to be impacted by non‐native species. Eutrophication was further found to decrease the impact of non‐native species on two functional diversity metrics: evenness and divergence. Our study therefore reveals that functional metrics are more sensitive than taxonomic metrics to anthropogenic stressors in the studied reservoirs. Still, the multiple linear regressions tested had overall low explanatory power. Further refinements will thus be needed to use this type of metrics in an impact assessment scheme. 相似文献
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Atlantic salmon, Salmo salar L., parr habitat characterisation is usually performed by in situ measures of key environmental variables taken at the exact fish location if the fishing gear allows precise pinpointing of this location, or in large sampling sections covering a river reach or mesohabitat, often ignoring variability in the immediate vicinity around individual fish. These data may be critically important in the development and validation of habitat preference models. The influences of seven increasing distances of measures, the variation of the number of considered measures and the depth of velocity measurement (bottom or 0.6 of the depth) in the calculations of HSI (Habitat Suitability Index) from a multiple‐experts fuzzy model of Atlantic salmon parr habitat were tested. When a parr was present, six measures collected in a 50‐cm radius around the fish to provide an average measure as input data and velocity measured at 60% of the depth gave the highest HSI values. These results show some potential for the use of an intermediate study scale, between micro‐ and mesohabitat, and questions how fish habitat conditions are currently measured. 相似文献
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- 1. Historically, ecological assessment of lakes has depended on open‐water chemical and phytoplankton analysis, with trophic status determined by chlorophyll a and total phosphorus following the general protocol of the OECD lake classification scheme. This has been accompanied by a prevailing opinion that the littoral zone of lakes is too heterogeneous to allow meaningful inter‐lake comparisons.
- 2. Council of the European Communities Directive 2000/60/EC establishing a framework in the field of water policy (the Water Framework Directive) requires a broader approach to ecological assessment, including the need to incorporate a range of biotic variables. This paper describes the results of a monitoring programme designed to determine within‐ and among‐lake variation of macroinvertebrate communities found in defined mesohabitats of 22 lakes incorporating a range of lake types. Three sampling approaches were applied to the study.
- 3. Triplicate macroinvertebrate samples from a cobble/pebble mesohabitat of 11 lakes showed that community composition from a standard habitat was robust.
- 4. Twinned samples from contrasting habitats of pebble/cobble and macrophyte dominated mesohabitats of 21 lakes had greater similarity within than among lakes. This showed that even across contrasting habitat structure, macroinvertebrate assemblages can provide a reliable lake‐specific indicator.
- 5. Multivariate analysis of replicate samples from 15 visually distinct mesohabitats in one lake showed that within‐lake variation could, nevertheless, be identified as distinct clusters of invertebrate assemblages.
- 6. Conclusions from the work are that variations within lakes were nested in among‐lake variation across a range of lake types, and that macroinvertebrate assemblages can provide meaningful assessment of ecological differences across lakes. Monitoring can, however, produce a substantial amount of ‘noise’ from the data that reflects the complexity of macroinvertebrate community structure in littoral zones. It is recommended that incorporation of macroinvertebrates in ecological assessment is most useful when confined to well defined mesohabitats rather than attempt to incorporate a complete range of mesohabitats within a single lake.
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Responsiveness of fish mass–abundance relationships and trophic metrics to flood disturbance,stream size,land cover and predator taxa presence in headwater streams 下载免费PDF全文
下载免费PDF全文 Kevin M. Fraley Helen J. Warburton Phillip G. Jellyman Dave Kelly Angus R. McIntosh 《Ecology of Freshwater Fish》2018,27(4):999-1014
Characterisation of food webs, by summarising energy transfer and trophic relationships, allows more functional measurement of ecosystems and may reveal threats (e.g., land‐cover change) in sensitive environments that are not obvious from conventional biomonitoring. However, typical methods used to achieve this are time‐consuming and expensive. Therefore, we tested the usefulness of fish‐focused food‐web proxies as functional measures, specifically mass–abundance relationships of fish assemblages and stable isotope (SI)‐derived metrics in headwater stream reaches. These metrics have been trialled before for similar use in other settings, but have yielded varying results, and have not been employed in tandem in temperate freshwaters. Sampling reaches (N = 46) were spread across a variety of streams, and the effects of habitat predictors at multiple scales on metrics were assessed using model selection. We found that habitat size positively correlated with food‐chain lengths in streams, possibly because of increased abundance of fish at multiple trophic levels in habitats with more space. Additionally, flood disturbance was negatively associated with fish mass–abundance and carbon range, likely due to the harshness of flood‐prone streams. Riparian land‐cover variables were correlated with multiple metrics, indicating the importance of terrestrial–aquatic linkages. Additionally, variations in all metrics were influenced by the presence of native, predatory longfin eels. Overall, we conclude that mass–abundance relationships and SI‐derived metrics are sensitive to drivers of trophic organisation and likely reflect processes occurring at multiple spatial scales in freshwaters. Thus, these metrics could be an insightful monitoring tool for managers because they reflect functional measures of aquatic ecosystems. 相似文献
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Zeb Tonkin Adrian Kitchingman Ben Fanson Jarod Lyon Renae Ayres Joanne Sharley Wayne M. Koster Justin O'Mahony Graeme Hackett Paul Reich Robin Hale 《水产资源保护:海洋与淡水生态系统》2020,30(7):1385-1396
- Removal of instream woody habitat (IWH) is one factor attributed to declines in fish populations worldwide. Restoration of IWH to help fish populations recover is now common; however, quantitative predictions about the outcomes of these interventions is rare. As such, quantitative links between IWH and fish abundance is of interest to managers to inform conservation and restoration activities.
- Links between instream habitat attributes, especially IWH, and selected fish species of recreational, cultural, and ecological significance were explored at 335 sites spanning eight streams across south‐eastern Australia. Data were collected on fish abundance and length, IWH density and a range of other habitat attributes at a scale that incorporated at least one of each of the major mesohabitat types (functional river elements). The data were analysed using Bayesian hierarchical generalized linear mixed models to examine fish habitat associations and used to make quantitative predictions of responses to future restoration.
- Strong positive relationships were found between fish abundance and IWH density and the strength of this relationship varied between species and waterways. Murray cod (Maccullochella peelii), a species commonly targeted by IWH interventions, displayed the strongest association with IWH density. River blackfish (Gadopsis marmoratus) also showed a significant relationship with IWH, but this effect was waterway specific. Fish length was only related to IWH for river blackfish. These results may reflect differences in the life histories of these two species. We suggest that differences in habitat association through ontogeny may be more relevant at smaller spatial scales.
- The results generated in this study can be used to guide waterway restoration and develop quantitative predictions about how fish might respond to IWH interventions across south‐eastern Australia. This approach provides a powerful quantitative framework within which to explore management options and objectives, and to test our predicted responses to habitat restoration.
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Luciano Lazzarini Wolff Edson Fontes de Oliveira Javier Lobón-Cerviá 《Ecology of Freshwater Fish》2023,32(1):195-208
Fish ecomorphological analyses often deal with several traits simultaneously, making it challenging to interpret general patterns, and have not addressed the longitudinal component of streams in morphology-habitat relationships. We identified ecomorphotypes of fishes and correlated their morphological variation with food, structural/hydrological variables, and abundances to detect their links with diet and local-scale habitat categories. Eighteen morphometric traits were obtained from specimens collected by electrofishing in a coastal Atlantic stream in Brazil. To test for morphology-habitat associations, headwaters, middle, and mouth reaches were divided into shorter sampling sites, with the middle reach being classified into riffle, run, and pool mesohabitats. Multivariate analyses highlighted the morphological variations and associated the form categories of 18 fish species with food and habitat categories. It resulted in four combined trophic and habitat ecomorphotypes: (1) benthic AB/lithophilic, composed of smaller to longer loricariids, detritivores, of fast-water, and pebbly habitats; (2) benthic C/lithophilic of very fast-waters, algal and detritus scrapers, with longer intestines than the other benthic species, wider suctorial mouths, inhabitants of headwaters, and riffles habitats; (3) nektobenthic/lithophilic with streamlined bodies, invertebrate feeders, and dwellers of faster-water, cobbly habitats; and (4) nektonic/limnophilic composed mainly by characins, which had strong correlations with terrestrial insect consumption, and lentic/pool, sandy habitats. The morphology–environment correlations linked these ecomorphotypes to the broad habitat gradient arrayed in longitudinal and local scales. These results permit inferring the larger form patterns expected for local fish assemblages and emphasise the fish trait categorisation as a possible surrogate to reveal broader ecomorphological associations. 相似文献