Sedentary fish as indicators of changes in the river flow rate after impoundment

Mendes, Yanne A.; Oliveira, Renata S.; Montag, Luciano Fogaça de Assis; Andrade, Marcelo C.; Giarrizzo, Tommaso; Rocha, Rossineide Martins da; Ferreira, María Auxiliadora Pantoja

doi:10.1016/j.ecolind.2021.107466

Cited by 12 publications

(9 citation statements)

References 62 publications

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“…Stained sections were analyzed, and photomicrographs were obtained using an Eclipse Ci‐S light microscope (Nikon, Japan) connected to a Nikon DS‐Ri1 digital camera. The gonadal stages were established following the classification adapted by Mendes et al (2021) in immature, maturing, mature and spawned (females)/spent (male) and cell types in type I, II, II and IV oocytes in females, and spermatogonia (Sg) spermatocytes (Sc), spermatids (St) and sperm (Sz) in males.…”

Section: Methodsmentioning

confidence: 99%

Evidence of secondary sexual dimorphism in King Tiger Plecos Hypancistrus sp, Loricariidae, of the Amazon River basin

Reis

Oliveira

Viana

et al. 2022

Aquaculture Research

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The aim of the present study was to describe the secondary sexual characteristics of adult Hypancistrus sp. A total of 120 specimens were used to evaluate the morphometric characters, to confirm the morphometric data, histological identification of sex and maturation stages of gonads was performed. The results showed that males had higher median total and standard body lengths, open fin length, right and left fin lengths, head length and width and inter‐eye width than females. However, the females showed a high median abdominal width. Both sexes presented odontodes along the body, with thick odontodes present near the interopercular region and pectoral fins. In mature males, small odontodes were present along the snout. Scanning microscopy analysis confirmed that odontodes in females had a thicker base than those in males, conferring the former with a “cone” morphology. Additionally, it was observed that males had a long and broad head with a triangular shape and "V"‐shaped genital papilla, while females had a round head and "U"‐shaped genital papilla. Thus, we conclude that Hypancistrus sp. had secondary sexual characteristics, being possible to differentiate the sex by the size of the body, abdominal width, shape of the head, size of the odontodes and distinct morphology of the ovipositor. This study will serve as a basis for the development of breeding protocols, as it aims to identify sexually mature males and females of Hypancistrus sp. for breeding in captivity.

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Section: Methodsmentioning

confidence: 99%

Evidence of secondary sexual dimorphism in King Tiger Plecos Hypancistrus sp, Loricariidae, of the Amazon River basin

Reis

Oliveira

Viana

et al. 2022

Aquaculture Research

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“…Although run‐of‐river dams are considered to generate hydropower with relatively reduced impacts (Gaudard, Avanzi & De Michele, 2018), owing to highly seasonal rainfall and river flow rates the vast majority of Amazonian run‐of‐river dams include reservoirs, e.g. Belo Monte (Hall & Branford, 2012), and can therefore exert drastic impacts on flow rates (Mendes et al, 2021). The results of the present study suggest that the dry season extent of river level rise is permanently at least 20 km beyond recognized limits.…”

Section: Discussionmentioning

confidence: 99%

Amazonian run‐of‐river dam reservoir impacts underestimated: Evidence from a before–after control–impact study of freshwater turtle nesting areas

Bárcenas-García

Michalski

Gibbs

et al. 2022

Aquatic Conservation

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Hydropower dams are associated with adverse impacts on biodiversity, yet there remains a lack of robust scientific evidence documenting the magnitude of these impacts, particularly across highly biodiverse tropical waterways. Aquatic and semi‐aquatic vertebrates are disproportionately affected by human changes to aquatic environments and hydropower expansion is an increasing threat to the Endangered yellow‐spotted river turtle (Podocnemis unifilis) across its tropical South American range. Yellow‐spotted river turtle nesting areas were monitored as an indicator of dry season river level changes following run‐of‐river dam reservoir filling. A before–after control–impact (BACI) study design was used with multi‐year field campaigns monitoring turtle nesting areas upstream of the dam. The cause and extent of changes in nesting areas were established using generalized additive models. Nesting area density was evaluated in relation to time (before vs. after), treatment (control vs. impact), time–treatment interaction (BACI), distance to the dam and precipitation. The extent of changes was examined by comparing the remaining proportion of nesting areas after reservoir filling. Dam construction generated an immediate and apparently permanent dry season river‐level rise that extended more than 20 km beyond impact assessment limits. On average the density of nesting areas declined by 69% (from 0.48 to 0.15 per km) across 33 km of river directly affected by the dam. This loss was reflected in a significant BACI interaction. Nesting area density was not explained by seasonal precipitation. Monitoring of freshwater turtle nesting areas provided an effective means to quantify hydropower dam impacts across biodiverse yet rapidly changing waterways. The adverse impacts documented in this study should be preventable by mitigation actions including habitat creation and dry season flow regulation. Such measures are also likely to benefit multiple sandbar‐nesting species (including turtles, crocodiles and birds) in tropical rivers increasingly influenced by run‐of‐river dams.

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“…Pollution-tolerant species like Capitella sp. have been reported to tolerate low oxygen conditions, hence considered an indicator of organic pollution [ 93 , 94 ]. Additionally, Nereis sp.…”

Section: Discussionmentioning

confidence: 99%

Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana

Lukhabi,

Mensah,

Asare

et al. 2024

Heliyon

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Sedentary fish as indicators of changes in the river flow rate after impoundment

Cited by 12 publications

References 62 publications

Evidence of secondary sexual dimorphism in King Tiger Plecos Hypancistrus sp, Loricariidae, of the Amazon River basin

Evidence of secondary sexual dimorphism in King Tiger Plecos Hypancistrus sp, Loricariidae, of the Amazon River basin

Amazonian run‐of‐river dam reservoir impacts underestimated: Evidence from a before–after control–impact study of freshwater turtle nesting areas

Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana

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