Influence of hydrological cycle on the composition and structure of fish assemblages in an igapó forest, Amazonas, Brazil

Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI) to two reservoirs in the Upper Paranapanema river basin, São Paulo State, Brazil. Methods The RFAI was adapted from metrics related to the functional characteristics and composition of fish assemblages through a protocol of metric selection and validation, and to its response to the presence of riparian vegetation. Results The final RFAI was composed by nine metrics, been lower in sites without riparian vegetation as consequence of the predominance of larger individuals and the percent of piscivorous and detritivorous fishes. Conclusions These results suggest that increasing shore habitat complexity in reservoirs by maintaining riparian vegetation increases fish biotic integrity.

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Effects of abiotic variables on the distribution of fish assemblages in streams with different anthropogenic activities in southern Brazil

Neotropical Ichthyology ◽

10.1590/s1679-62252012000300018 ◽

2012 ◽

Vol 10 (3) ◽

pp. 643-652 ◽

Cited By ~ 15

Author(s):

Vanessa Salete Daga ◽

Éder André Gubiani ◽

Almir Manoel Cunico ◽

Gilmar Baumgartner

Keyword(s):

Native Species ◽

Fish Assemblages ◽

Anthropogenic Activities ◽

Southern Brazil ◽

Urbanization Gradient ◽

Composition And Structure ◽

Matrix Correlation ◽

Abiotic Variables ◽

The Relationship ◽

Distribution Of Fish

Studies on fish assemblages in streams point out, that understanding the relationship between species and their environment is crucial for conservation. The present study aimed at evaluating the effects of changes in abiotic variables on the composition and structure of fish assemblages in Neotropical urban streams from southern Brazil with different levels of urbanization. The composition and structure of fish assemblages showed significant differences along the urbanization gradient observed in the streams. Tolerant and non-native species were found in more urbanized sites. A matrix correlation revealed a relationship between abiotic variables and the spatial pattern of structure and composition of fish assemblages. Abiotic variables, such as total phosphorus, dissolved oxygen, and conductivity, determined the distribution of fish assemblages. Streams without urban influence exhibited intrinsically low species richness, suggesting that they are highly susceptible to species loss and diversity reduction. Thus, changes in water quality or hydrological conditions induced by urbanization may intensify these impacts.

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Dams and the fish fauna of the Neotropical region: impacts and management related to diversity and fisheries

Brazilian Journal of Biology ◽

10.1590/s1519-69842008000500019 ◽

2008 ◽

Vol 68 (4 suppl) ◽

pp. 1119-1132 ◽

Cited By ~ 372

Author(s):

AA. Agostinho ◽

FM. Pelicice ◽

LC. Gomes

Keyword(s):

Fish Assemblages ◽

Fish Fauna ◽

Neotropical Region ◽

Life Cycles ◽

Fish Diversity ◽

Negative Consequences ◽

Long Distance ◽

Management Actions ◽

Composition And Structure ◽

Almost All

Reservoirs have been built in almost all of the hydrographic basins of Brazil. Their purposes include water supply for cities, irrigation and mainly, generation of electricity. There are more than 700 large dams and associated reservoirs in the large rivers of the country. These reservoirs favor local and regional economic development, but they also bring serious and irreversible alterations in the natural hydrologic regime of rivers, affecting habitat quality and the dynamics of the biota. In the impounded area, the main impact is the change from lotic to lentic water, which influences aquatic fauna, including fishes. Impacts of reservoirs present relevant spatiotemporal variations. Immediately after reservoir formation, fish species richness usually increases due to incorporation of surrounding habitats, but richness decreases as reservoirs age. However, impacts downstream of dams appear to be similar or stronger than those that occur within the reservoir. Dams promote discharge control, altering the seasonal cycles of floods. These effects are augmented when dams are constructed in cascades. Therefore, dams profoundly influence composition and structure of fish assemblages. Most affected species are the rheophilics and long distance migratory that require distinct habitats to fulfill their life cycles. Populations of migratory species may collapse or even disappear in intensely regulated stretches. Management actions taken to minimize impacts of dams in Brazil historically considered construction of fish passages, fishery control and stocking. The results of these actions are questionable and/or with clear failures. In this paper, we give emphasis to the Paraná River basin, the most affected by dams in Brazil. We describe some patterns in the alteration and decline in fish diversity in areas influenced by dams. We also discuss negative consequences in the fishery and ecosystems functioning. Finally, we argue the relevance and the success of the management actions taken and present some suggestions to improve conservation of the ichthyofauna in South American basins influenced by dams.

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Trophic ecology of the ichthyofauna of a stretch of the Urucu River (Coari, Amazonas, Brazil)

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x2013000100007 ◽

2013 ◽

Vol 25 (1) ◽

pp. 54-67 ◽

Cited By ~ 2

Author(s):

Igor David da Costa ◽

Carlos Edwar de Carvalho Freitas

Keyword(s):

Trophic Structure ◽

Trophic Ecology ◽

Fish Assemblages ◽

Hydrological Cycle ◽

Taxonomic Diversity ◽

Dry Season ◽

Water Levels ◽

Seasonal Fluctuations ◽

Flood Season ◽

Wide Range

INTRODUCTION: The floodplains of the large Amazonian rivers are very productive as a result of seasonal fluctuations of water levels. This favors the fishes as they are provided with a wide range of habitats and food resources; AIM: In this study, we identified the trophic structure of fish assemblages in the upper river Urucu area (State of Amazonas - Brazil), observing seasonal changes determined by the hydrological cycle; Methods: Samples were collected with the aid of gillnets, during the flood season (April/2008) and the dry season (August/2008) in areas upstream and downstream of ports of the Urucu river within the municipality of Coari, Amazonas, Brazil; RESULTS: 902 individuals of seven orders, 23 families and 82 species were collected. Fishes were more abundant in the dry season than in the flood season, and the piscivores and carnivores (Serrasalumus rhombeus and Osteoglossum bicirrhosum) were the most significant trophic categories in the dry season whereas piscivores and insectivores (Serrasalumus rhombeus, Bryconops alburnoides and Dianema urostriatum) were more abundant in the flood season. The trophic diversity, dominance and evenness were very similar in all sampling periods and show lower values than taxonomic index patterns, except for the trophic dominance in the dry season. Taxonomic diversity and dominance were higher in the flood season if compared to the dry season, but figures were quite uniform and there were no great discrepancies between seasons. CONCLUSION: We found through our studies that the dry and flood seasons work as regulatory factors of abundance of fishes of certain trophic categories in the Urucu river, what can be possibly explained by the availability of resources and the food spectrum of each category.

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Assessing fish assemblages similarity above and below a dam in a Neotropical reservoir with partial blockage

Brazilian Journal of Biology ◽

10.1590/s1519-69842013000400007 ◽

2013 ◽

Vol 73 (4) ◽

pp. 727-736 ◽

Cited By ~ 1

Author(s):

FG. Araújo ◽

ABI. Santos ◽

RJ. Albieri

Keyword(s):

Fish Assemblage ◽

Fish Assemblages ◽

Fish Passage ◽

Migratory Species ◽

Wet Season ◽

Prochilodus Lineatus ◽

Oxygen Conductivity ◽

Composition And Structure ◽

Pimelodus Maculatus ◽

Hoplosternum Littorale

Damming rivers disrupts the water flow and changes the ichthyofauna organisation. We investigated an impoundment with permanent connection and homogeneous environmental conditions between the zones above and below the dam. Temperature was comparatively higher during wet season irrespective of zone, and both zones had higher dissolved oxygen, conductivity and transparency in the dry season. A total of 1687 individuals comprising 27 species were collected in the downriver zone, while the reservoir had 879 individuals and 23 species. Each zone had different fish assemblage composition and structure, but assemblages were not explained by the examined environmental variables (r2 = 0.08; p = 0.307). Migratory species such as Pimelodus maculatus, Pimelodus fur, Leporinus copelandii and Prochilodus lineatus were the most affected, and probably are prevented to perform upriver migrations. On the other hand, lentic adapted species such as G. brasiliensis, Hoplias malabaricus and Hoplosternum littorale successfully colonised the reservoir. Therefore we conclude that the presence of the lateral hydrological connectivity alone does not guarantee the ecological connectivity since fish assemblage similarity differed between the two zones. Fish passage facilities should be monitored and managed to evaluate and improve their functionality.

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Community structure of temperate reef fishes in kelp-dominated subtidal habitats of northern Chile

Marine and Freshwater Research ◽

10.1071/mf06200 ◽

2007 ◽

Vol 58 (12) ◽

pp. 1069 ◽

Cited By ~ 43

Author(s):

Alejandro Pérez-Matus ◽

Lara A. Ferry-Graham ◽

Alfredo Cea ◽

Julio A. Vásquez

Keyword(s):

Species Richness ◽

Fish Species ◽

Fish Assemblages ◽

Sea Water ◽

Reef Fishes ◽

Northern Coast ◽

Northern Chile ◽

Temperate Reef ◽

Composition And Structure ◽

Study Sites

An important aim of fish ecology is to understand and predict patterns of distribution and abundance in marine communities. Such patterns were examined at four kelp-dominated sites along the northern coast of Chile (19° through 30° S) over 1 year. Fish species richness, diversity and abundance estimates obtained via observational and destructive sampling methods were compared among sites as were habitat and environmental variables that characterised the sites; including sea water temperature below the surface, nutrients, productivity, visibility, density of macroalgae stands, and percentage cover of observed microhabitats (including understorey algae and faunal assemblages). In total, 19 fish species belonging to 14 families were observed from all sites. Species richness and diversity were highest in sites where kelp canopy was composed of two species and where kelp was densest, although only species diversity was significantly different among sites. The sites with high kelp density, in turn, sustained abundant habitat-forming species in the kelp understorey. Principal coordinate analysis indicated that the composition and structure of the fish assemblages varied significantly with depth at all study sites. The depth distribution of fishes was correlated with the arrangement of site-specific biological microhabitats, defined by the algae or invertebrate species that form the microhabitat. Temperature, productivity, and nutrients did not vary consistently across study sites, but did vary within individual sites. We suggest that kelp cover and composition strongly affects the diversity and distribution of fishes at shallow coastal habitats in northern Chile through the availability of microhabitats.

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When roads cross streams: fish assemblage responses to fluvial fragmentation in lowland Amazonian streams

Neotropical Ichthyology ◽

10.1590/1982-0224-2020-0031 ◽

2020 ◽

Vol 18 (3) ◽

Author(s):

Gabriel L. Brejão ◽

Fabrício B. Teresa ◽

Pedro Gerhard

Keyword(s):

Fish Assemblages ◽

Landscape Fragmentation ◽

Taxonomic Composition ◽

Longitudinal Distribution ◽

Aquatic Communities ◽

Natural Landscape ◽

Composition And Structure ◽

Line Transects ◽

Fish Dispersal

ABSTRACT Roads affect biodiversity by increasing mortality rates, habitat loss, and natural landscape fragmentation. Poorly installed culverts can impound streams, changing the environmental conditions, and affecting aquatic communities. We evaluated the effects of road crossings on the taxonomic composition and functional structure of fish assemblages in lowland eastern Amazonian streams, Brazil. We tested the hypothesis that the presence of road-derived impoundments affects assemblage taxonomic and functional composition and structure. Two predictions were addressed: (1) Species and functional group composition will differ in impounded reaches in relation to lotic reaches; (2) Assemblages in downstream lotic reaches will be richer in species and functional groups in relation to upstream lotic and impoundment reaches. We sampled five streams crossed by roads presenting impoundment formation, conducted by visual census (day, dusk, and night) in 200 m line transects. Assemblage composition from lentic reaches was different from lotic reaches, and Shannon diversity from downstream reaches was different from upstream and impoundment, however, beta diversity partitioning between lotic reaches showed higher nestedness contribution, reinforcing the role of impoundment in limiting fish dispersal between lotic reaches. These results suggest that impoundments impose environmental and dispersal constraints to fish, affecting their longitudinal distribution in streams fragmented by roads.

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Hydrology-driven seasonal changes in the phytoplankton of a subtropical river (Riacho Formosa, Argentina).

Boletín de la Sociedad Argentina de Botánica ◽

10.31055/1851.2372.v53.n2.20575 ◽

2018 ◽

Vol 53 (2) ◽

pp. 183-193

Author(s):

Gabriela Mataloni ◽

Luciana Burdman ◽

Valeria Casa ◽

Daniela Gonzalez ◽

María Clara Masetti

Keyword(s):

Phytoplankton Community ◽

Hydrological Cycle ◽

Species Turnover ◽

Warm Season ◽

Late Winter ◽

Subtropical Region ◽

Paraguay River ◽

Composition And Structure ◽

Depth Water ◽

High Phase

The Riacho Formosa is one of many autochtonous watercourses running along the subtropical region of the Wet Chaco Plains and draining into Paraguay River. Their typical hydrological cycle is characterized by a late winter low phase and a high phase throughout the warm season. As part of a baseline characterization, the composition and structure of the phytoplankton were studied in relation to river depth, water temperature, pH, conductivity and transparency through 4 seasonal samplings between June 2015 and March 2016. A rich phytoplankton community (338 taxa) was revealed in this study. A few species of Cryptophyceae and Euglenophyceae dominated the community, especially during low waters. A cluster analysis showed that community compositions were more dissimilar over time than along the watercourse, and were spatially more homogeneous during high waters. A canonical correspondence analysis showed that environmental features significantly explained 42.6% of the total variance of species data (p= 0.004). We conclude that phytoplankton responds to hydrological changes through a high species turnover, with dominance peaks of euryhaline, shadow adapted and organic matter exploiting taxa during low waters.

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Stability and spatio-temporal structure in fish assemblages of two floodplain lagoons of the lower Orinoco River

Neotropical Ichthyology ◽

10.1590/s1679-62252009000400022 ◽

2009 ◽

Vol 7 (4) ◽

pp. 719-736 ◽

Cited By ~ 3

Author(s):

Nirson González ◽

Carlos Lasso ◽

Judith Rosales

Keyword(s):

Aquatic Vegetation ◽

Fish Assemblages ◽

Hydrological Cycle ◽

Temporal Structure ◽

Biotic Interactions ◽

High Water ◽

Water Phase ◽

Fish Assemblage Structure ◽

Biological Interactions ◽

The Mean

Fish assemblage structure and variability were analyzed in two floodplain lagoons (Las Arhuacas and Los Cardonales) along the lower Orinoco over a hydrological cycle. Every three months during continuous three-day sampling, experimental gill nets (5 to 12.5 cm of mesh opening) and 1 mm-mesh seine nets were utilized according to the types of habitats presents. A total of 133 fish species were found in Las Arhuacas and 95 species in Cardonales. Fifty five and 17 species were exclusive to Las Arhuacas and Los Cardonales respectively, and 77 were common to both lagoons. In Las Arhuacas, the most speciesrich orders were Characiformes, Siluriformes, Perciformes and Gymnotiformes and in Los Cardonales, the most species-rich orders were Characiformes, Siluriformes, Clupeiformes and Perciformes. The richness, abundance and biomass were significantly higher (p < 0.001) in Arhuacas than in Cardonales. In general, the fishes assemblage was highly variable during the high water phase and moderately stable during low water phase in both lagoons, with more stability or less variability in Cardonales than Arhuacas. Also, there were significant differences in the fish assemblages between the two lagoons, mainly during low waters (ANOSIM; p < 0.001). The species that contributed most to the mean dissimilarity between the lagoons were Hypostomus argus, Aphanotorulus ammophilus, Potamorhina altamazonica, Prochilodus mariae, Loricaria gr. cataphracta, Oxydoras sifontesi, Hydrolycus armatus, Hyphopthalmus edentatus and Pterodoras rivasi. The last four species were more commonly collected in Los Cardonales. Also, the species of small size (mainly SL < 5 cm) such as Rhinosardinia amazonica, Moenkhausia sp. 1 "lepidura", Moenkhausia sp. 2, Aphyocharax alburnus, Characidium sp. 1, Moenkhausia sp. 3, Exodon paradoxus and Roeboides dientonito contributed to the mean dissimilarity among the beach and aquatic vegetation habitats. The patterns of the species assemblage organization were related to the dynamics of the floods. Non-random (i. e., deterministic) associations between species caused by the selection of habitats and/or to biological interactions, apparently were more common during low waters when there is an increased density of fish and so the biotic interactions are intensified. Stochastic associations, on the other hand, seemed to be more common during high water when species are more dispersed.

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Factors determining the structure of fish assemblages in Tarumã River, Jaru Biological Reserve, Machado River drainage, northern Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-2020-0111 ◽

2021 ◽

Vol 19 (4) ◽

Author(s):

Igor D. Costa ◽

Natalia N. Santos Nunes ◽

Carlos E. C. Freitas

Keyword(s):

Species Composition ◽

Environmental Variables ◽

Fish Assemblages ◽

Hydrological Cycle ◽

Principal Component ◽

High Water ◽

Environmental Data ◽

Partial Redundancy Analysis ◽

The Individual ◽

Biological Reserve

ABSTRACT Few studies on fish assemblages and relations with environmental factors in aquatic systems in southeastern Amazonia have been carried out when compared to other areas in the Amazon. Therefore, which are the main environmental variables and processes responsible for structuring them remains unknown. We hypothesized that fish assemblages respond the variation in the physical-chemistry variables between seasons of the hydrological cycle in a pristine river in the Amazon. The study was performed on fish assemblages of the Tarumã River, Jaru Biological Reserve, Rondônia. Samplings were carried out in five sites along the river in March and September, 2015, which included fish collection and environmental data measurements. Principal component analysis was performed to ordinate the sites in high water and low water seasons, according to environmental variables. We used a similarity analysis in order to identify the individual contribution of species in hydrological period and a partial redundancy analysis for quantify the relative importance of environmental variables in the species composition. As predicted by our hypothesis, the species composition was influenced by dissolved oxygen and temperature. Myloplus rubripinnis, Serrasalmus compressus, and S. rhombeus were the most abundant during high water, while S. rhombeus, Myloplus lobatus, Prochilodus nigricans, and Hydrolycus armatus were the dominant species during the low water.

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