Tributaries as richness source for Oligochaeta assemblage (Annelida) of Neotropical dammed river

Ragonha, Flávio Henrique; Petsch, Dk.; Alves, Gustavo Henrique Zaia; Santana, Herick Soares de; Michelan, Thaísa Sala; Takeda, Alice Michiyo

doi:10.1590/1519-6984.05613

Cited by 11 publications

(6 citation statements)

References 24 publications

(26 reference statements)

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“…Studies carried out on this same floodplain reported that the abundance of small fishes such as Astyanax lacustris (Lütken 1875) increased three times after damming (Baumgartner et al., ). For macroinvertebrates, the abundance of Chaoborus (main zooplankton predator), for example, is higher in the dammed river than in the preserved river (Ragonha et al., ). Thus, we cannot exclude the potential effect of predation and other types of interactions in our results, as they possibly influence the intensity of relationships between the environmental variables and functional β‐diversity.…”

Section: Discussionmentioning

confidence: 99%

Effects of dams decrease zooplankton functional β‐diversity in river‐associated lakes

et al. 2018

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In river–floodplain systems, the construction of dams causes environmental changes in the natural dynamics of rivers and the associated wetlands, which can affect both the taxonomic and functional composition of communities, and, consequently, ecosystem functioning. We evaluated zooplankton taxonomic and functional β‐diversity in sets of lakes associated with a preserved and a dammed river in a Neotropical floodplain. We expected that both β‐diversity measures would be lower in lakes associated with a dammed river than in lakes associated with a preserved river. β‐Diversity was partitioned into turnover and nestedness components, through multiple‐site dissimilarity measures, and compared with expected null models. We expected that nestedness would be more important for both the β‐diversity measures in lakes associated with the dammed river, whereas species and trait turnover would be more important in lakes associated with the preserved river. Functional β‐diversity was higher among lakes of the preserved river than of the dammed river, while taxonomic β‐diversity was not different between the rivers. Contributions of turnover and nestedness components were similar in the preserved river, whereas that of nestedness was higher in the dammed river, revealing the loss of extreme trait combinations from the functional space. Comparisons between observed and expected β‐diversity revealed a higher trait turnover than would be expected by species turnover in the preserved river, and no differences from the null models were observed in lakes associated with the dammed river. Our results suggest that dissimilarity in trait composition is influenced more by environmental changes associated with river damming than by dissimilarity in species composition such that a functional homogenisation occurs without a change in taxonomic β‐diversity. We propose the maintenance of preserved tributaries in floodplains, which sustain environmental heterogeneity, primarily if the nearby environments are already dammed. Furthermore, we reinforce the necessity of a pluralistic approach, considering both taxonomic and functional aspects of biodiversity in ecosystem management.

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Section: Discussionmentioning

confidence: 99%

Effects of dams decrease zooplankton functional β‐diversity in river‐associated lakes

et al. 2018

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“…() clearly highlighted the spatial displacement that building a reservoir can impose on species, since there is a natural tendency for individuals to seek more suitable locations similar to their environmental profile prior to the formation of the reservoir. The importance of maintaining dam‐free tributaries is widely proven, not only for fish but for other assemblages such as macroinvertebrates and zooplankton (Ragonha et al., ; Braghin et al., ).…”

Section: Discussionmentioning

confidence: 99%

Patterns of reproduction and growth of the catfishIheringichthys labrosus(Lütken, 1874) after a reservoir formation

2016

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Summary This work contributes to the knowledge of the reproduction, growth parameters and mortality rates of Iheringichthys labrosus in a newly‐formed reservoir. A total of 554 males and 1227 females were collected over 12 consecutive months, 1998–1999, from sites in the Corumbá Reservoir, Brazil, using gillnets (meshes: 2.4–16 cm). Information on each individual, i.e. standard length (cm), weight (g), sex, and gonadal development phase was recorded. The pectoral spines were removed to estimate age. The number of juveniles and adults, males and females, reproductive sites and seasons were estimated. First maturation length was estimated using a likelihood function fitted by binomial distribution. Growth parameters were estimated using the von Bertalanffy equation. Total instantaneous mortality was obtained through a linearized catch curve method. Standard length varied from 6.0 to 20.5 cm. Growth showed negative allometry for both sexes. The reproduction period was August to December in all environments sampled and first maturation length was 11.5 cm. All individuals were adults with 17.0 cm standard length. Ages varied from zero to 7 years. Asymptotic length, growth coefficient and t0 for the entire population were 27.79 cm, 0.12 and −2.64, respectively. Instantaneous and annual mortality rates were 0.90 and 0.59, respectively.

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“…Studies previously reported the direct positive influence of tributaries to the main river in a hydrographic basin (Rice et al, 2001). Considering this stretch of the Paraná River floodplain, tributaries are beneficial to several communities, as a source of food resources and nutrients, and areas for refuge and fish spawning (Ragonha et al, 2014;Braghin et al, 2015). These two tributaries are located in the preserved area, had higher values of total solid materials and nutrients (Santana et al, 2017, in this volume).…”

Section: Discussionmentioning

confidence: 60%

Influence of tributaries on the periphytic diatom community in a floodplain

et al. 2017

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In impacted floodplains, small tributaries have an essential role in the maintenance of ecosystem biodiversity. Aim: We aimed to characterise the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain considering the importance of tributaries as a source of propagules. The purpose of this study was to understand the influence of the tributaries in the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain. We expect that species present in the main river channel (mainly in the last stretch) would be a subset of the community present in the tributaries. Methods The study area is located in the last non-dammed stretch of the Paraná River in this floodplain, with the contribution of several tributaries. Sampling was performed in 2014 in two tributaries and three sites at the Paraná River main channel, and the periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results We identified 115 diatom taxa. Higher values of species richness were registered in the tributaries, and higher densities in the tributaries and at sampling sites under the direct influence of the tributaries. We also observed a higher similarity between the tributaries, which are located in the preserved side of the floodplain. The results of beta diversity showed that closer sites had lower values, and that the species turnover was the component more important in this floodplain. Conclusion In this way, these results reinforce the importance of tributaries mainly on the algae establishment and development reflected in the density of species. It demonstrates that sites in preserved area present a higher species richness and can serve as a pool of propagules for downstream environments.

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Tributaries as richness source for Oligochaeta assemblage (Annelida) of Neotropical dammed river

Cited by 11 publications

References 24 publications

Effects of dams decrease zooplankton functional β‐diversity in river‐associated lakes

Effects of dams decrease zooplankton functional β‐diversity in river‐associated lakes

Patterns of reproduction and growth of the catfishIheringichthys labrosus(Lütken, 1874) after a reservoir formation

Influence of tributaries on the periphytic diatom community in a floodplain

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