Article
Environmental Sciences
Simon Fuehrer, Daniel S. Hayes, Thomas Hasler, David R. M. Graf, Elora Fauchery, Daniel Mameri, Stefan Schmutz, Stefan Auer
Summary: This study quantifies the consequences of flow down-ramping on nase larvae, revealing differences between larval stages. Lower sloped riverbanks and higher down-ramping rates lead to higher stranding rates. There are differences in stranding rates between day and night. These findings contribute to a deeper understanding of the effects of artificial sub-daily flow fluctuations on cyprinid fish and can inform mitigation strategies for hydropower operations.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Environmental Sciences
D. Mameri, D. S. Hayes, S. Fuehrer, E. Fauchery, S. Schmutz, A. Monserat, T. Hasler, D. R. M. Graf, J. M. Santos, M. T. Ferreira, S. Auer
Summary: Research on the effects of intermittent water releases from hydropower plants on fish early life stages has shown that flow and thermal fluctuations can impact fish movement patterns and migration. A study using experimental outdoor channels found that a rapid drop in water temperature during hydropeaking increased fish drift, especially when accompanied by pronounced water temperature drops. Cold thermopeaking may result in higher drift rates compared to hydropeaking with stable water temperature. Monitoring and adjusting water temperature can help mitigate the impacts of hydropower on aquatic organisms.
Article
Ecology
Ruamruedee Panchan, Kurt Pinter, Stefan Schmutz, Guenther Unfer
Summary: This study monitored the migration patterns and habitat use of adult barbel and nase in the Danube River. The results showed that both species utilized the entire width and depth spectrum of the river. The habitat use differed between the two species, with nase primarily found in the free-flowing section and barbel mainly using deep areas of the impoundment.
ENVIRONMENTAL BIOLOGY OF FISHES
(2022)
Article
Environmental Sciences
Dusan Nikolic, Srdan Subotic, Stefan Skoric
Summary: This study analyzed individuals of common nase from waterbodies with different characteristics and levels of anthropogenic pressure. The results showed that the type of ecosystem and the degree of anthropogenic pressure are important factors in environmental pollution. The fish meat had low levels of metal pollution and was safe for consumption.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Bernhard C. Stoeckle, Melanie Mueller, Christoffer Nagel, Ralph Kuehn, Juergen Geist
Summary: Supportive breeding programmes are crucial for the conservation of declining freshwater fishes. However, breeding offspring can lead to decreased genetic diversity and inbreeding effects. Genetic analysis shows significant genetic differentiation between captive-bred common nase and wild populations, with lower genetic diversity and signs of inbreeding in the captive-bred and one of the natural populations.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS
(2022)
Article
Fisheries
Christoffer Nagel, Christina Spiessl, Joachim Pander, Juergen Geist
Summary: This study established a standardized protocol for assessing the egg surface quality of common nase eggs using SEM images, and found significant differences in egg surface properties among individual females and among different populations. These differences were mainly attributed to length variability and merging of adhesive villi, as well as to coating and filament-like connections of these structures. Further investigations are needed to better understand the relationship of egg surface properties, egg stickiness, and hatching success for early life stages in freshwater fish.
JOURNAL OF APPLIED ICHTHYOLOGY
(2021)
Article
Ecology
Scott C. Burgess, Michael Bode, Jeffrey M. Leis, Luciano B. Mason
Summary: Dispersal is influenced by interactions between an individual's phenotype and the environment, leading to complex variations in distances and directions of dispersal. Larval swimming behavior, along with other factors like depth and navigation, affects dispersal and settlement patterns, with faster swimming larvae showing increased probabilities of settlement and longer dispersal distances.
Article
Environmental Sciences
Yu Gao, Li Chen, Wei Zhang, Xin Li, Quanxi Xu
Summary: This study examined the impacts of the Three Gorges Dam impoundment on the flow process, sediment transport, and river morphology in the downstream reaches of the Yangtze River. Results indicated that characteristic discharge decreased post-dam construction, with significant spatial variations along the river. The study provides valuable insights for assessing the channel-forming capacity of flow-sediment regimes worldwide and predicting river morphology evolution.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Rebecca Fisher, Jeffrey M. Leis, J. Derek Hogan, David R. Bellwood, Shaun K. Wilson, Suresh D. Job
Summary: This article presents a collation of data on swimming abilities of tropical marine fish larvae and pelagic juveniles, providing valuable information for studying larval swimming performance and other comprehensive research.
Article
Biodiversity Conservation
Christoffer Nagel, Jan Droll, Katharina Kroemer, Joachim Pander, Juergen Geist
Summary: This study tested the effect of PIT tags implanted into common nase and European barbel. The results demonstrated the suitability of this tagging technique for these fish species, which is of high methodological importance for assessing freshwater fish conservation in European rivers.
ANIMAL BIOTELEMETRY
(2023)
Article
Agriculture, Dairy & Animal Science
Petya Zaharieva, Diana Kirin
Summary: The study investigated the cadmium content in tissues and organs of common nase and water and sediments in the Danube River ecosystem. The highest concentration of cadmium was found in the liver of common nase. Additionally, the study compared the specified norms in national and international documents with the actual concentrations obtained.
SCIENTIFIC PAPERS-SERIES D-ANIMAL SCIENCE
(2021)
Article
Agriculture, Dairy & Animal Science
Radoslava Zaharieva, Diana Kirin
Summary: The study found that common nase from the Danube River near Kudelin village is a new host for P. torulosus, and Contracaecum sp. larvae is the main parasite species. Contracaecum sp. larvae showed high mean intensity and abundance in this ecosystem.
SCIENTIFIC PAPERS-SERIES D-ANIMAL SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Shihao Liu, John A. Goff, Shu Gao, Aiping Feng, Ya Ping Wang, Jianjun Jia, Weifen Hu, Wei Feng, Yonggui Yu
Summary: Many mega-river deltas in the world are deteriorating due to the lack of sediment supply. This study investigates the geomorphological and sedimentary evolution of a recently abandoned Huanghe delta lobe using bathymetric and seismic data. The study finds that mass wasting and sediment failure contribute to the degradation of the delta, and gravity-driven sedimentation plays a significant role in the evolution of the delta front. Additionally, alongshore hydrodynamic processes, particularly tidal remolding, result in the formation of shore-parallel submarine channels. These findings highlight the importance of sediment gravity flows and hydrodynamic redistribution in understanding the degradation of delta fronts.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Ecology
Brandon J. Sansom, Bruce C. Call, Carl J. Legleiter, Robert B. Jacobson
Summary: The pallid sturgeon species has been negatively affected by channel modifications in the Lower Missouri River, which have altered its habitat and hindered its migration. However, a rehabilitation project aimed at improving the river's conditions for the sturgeon larvae has shown promising results.
ECOLOGICAL ENGINEERING
(2023)
Article
Oceanography
Xiaolei Liu, Yang Lu, Heyu Yu, Lukuan Ma, Xingyu Li, Weijia Li, Hong Zhang, Changwei Bian
Summary: Two comprehensive and long-term observation campaigns were conducted at the subaqueous Yellow River delta, revealing high suspended sediment concentration and wave-supported fluid mud activity. The factors influencing the generation and dissipation of wave-supported fluid mud were investigated, and the characteristics and velocity of the mud flow were estimated. This study also highlighted the frequent occurrence of wave-supported fluid mud events at the abandoned Yellow River delta and emphasized the significance of studying its roles in sediment transport and offshore engineering.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Engineering, Civil
Johannes Schobesberger, Dominik Worf, Petr Lichtneger, Sencer Yuecesan, Christoph Hauer, Helmut Habersack, Christine Sindelar
Summary: This study experimentally investigates entrainment events of a single sediment particle on a smooth bed in open channel flow. Tomographic particle tracking velocimetry system and shake the box algorithm were used to determine flow velocities, while proper orthogonal decomposition method was applied to identify motions carrying the most turbulent kinetic energy.
JOURNAL OF HYDRAULIC RESEARCH
(2022)
Article
Ecology
Maristela C. Makrakis, Alcione Refatti, Hubert Keckeis, Patricia S. da Silva, Lucileine de Assumpcao, Elaine A. L. Kashiwaqui, Paulo E. Gamaro, Sergio Makrakis
Summary: The seasonal drift patterns of fish eggs and larvae were analyzed downstream the Iguacu River Falls to the confluence with Parana River, indicating a spatial, longitudinal distribution of larvae with higher numbers in the upper section. The study found that eggs and larvae densities varied between spawning seasons, with differences more pronounced in eggs than larvae. Furthermore, the presence of high abundance of buoyant eggs in drift suggests fish spawning in rapid and turbulent waters, with rainfall and turbidity potentially being main triggers for spawning.
Article
Water Resources
Daniel Wildt, Christoph Hauer, Helmut Habersack, Michael Tritthart
Summary: In this study, a Euler-Lagrangian two-way coupled large eddy simulation was used to model the development of sediment plume. The momentum exchange was calculated based on interaction forces in the Maxey-Riley equation. The results were validated against experimental data and showed good agreement. The analysis revealed three phases of sediment plume development: acceleration, transport, and deposition. The significant slowing down of fluid flow and particle sorting were identified as important processes in the initial development of sediment plume, which are not accounted for in one-way coupled models.
ADVANCES IN WATER RESOURCES
(2022)
Article
Fisheries
Rick J. Stoffels, Paul Humphries, Nick R. Bond, Amina E. Price
Summary: Lateral Hydrological Connectivity (LHC) is fragmented in river-floodplain ecosystems. Existing frameworks lack mechanistic details for decision-making. A new framework integrating all life-stages and spatial features is needed to assess risks and opportunities of LHC rehabilitation strategies.
FISH AND FISHERIES
(2022)
Article
Engineering, Civil
Sencer Yucesan, Johannes Schobesberger, Christine Sindelar, Christoph Hauer, Helmut Habersack, Michael Tritthart
Summary: A Large Eddy Simulation was conducted to study coherent structures in a fully developed turbulent open-channel flow. The forces acting on a stationary sediment particle were computed to predict the particle motion using the impulse concept. The results showed outward and sweep events in high impulse quadrant analyses. The correlation between hydrodynamic forces and the flow field was analyzed. It was found that large, long-lived hairpin-like vortices with bed-normal lengths larger than approximately 100 viscous units increased both lift and drag forces, facilitating the initiation of particle motion.
JOURNAL OF HYDRAULIC RESEARCH
(2022)
Article
Mechanics
Dominik Worf, Ali Khosronejad, Thomas Gold, Kevin Reiterer, Helmut Habersack, Christine Sindelar
Summary: The study investigated the behavior of a subaqueous cylindrical pendulum and corresponding flow dynamics, finding that two-dimensional model equations were able to capture three-dimensional dynamics. Three-dimensional vortical flow structures were observed during the experiments.
Article
Environmental Sciences
Markus Eder, Francesca Perosa, Severin Hohensinner, Michael Tritthart, Sabrina Scheuer, Marion Gelhaus, Bernd Cyffka, Timea Kiss, Boudewijn Van Leeuwen, Zalan Tobak, Gyorgy Sipos, Nandor Csikos, Anna Smetanova, Sabina Bokal, Andrea Samu, Tamas Gruber, Andreea-Cristina Galie, Marinela Moldoveanu, Petrisor Mazilu, Helmut Habersack
Summary: This paper presents methods to identify active, former, and potential floodplains, and their application to the Danube River. The extent of Danube floodplains has been reduced by around 79%. The share of active and potential floodplains in relation to former floodplains ranges between 5% and 49%.
Article
Environmental Sciences
Rolf Rindler, Sabrina Schwarz, Marcel Liedermann, Dorian Shire-Peterlechner, Andrea Kreisler, Johann Aigner, Michael Tritthart, Helmut Habersack
Summary: This study analyzed the distribution of bedload transport over a river cross-section by statistically analyzing long-term monitoring data. An innovative integrated measurement system was used to generate continuous, high-resolution, long-term monitoring data of bedload transport characteristics. The study found that the effective bedload transport width depends on the discharge rate and local transport capacity, and bedload transport over the entire river width only occurs at high flows that prevail a few days a year.
INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH
(2023)
Article
Mechanics
S. Yuecesan, D. Wildt, P. Gmeiner, J. Schobesberger, C. Hauer, C. Sindelar, H. Habersack, M. Tritthart
Summary: Studies on turbulent flows over heterogeneous surfaces have found increased turbulent kinetic energy and Reynolds shear stress in low-momentum-path regions, which induce large-scale multi-cellular secondary flows. This study aims to analyze the influence of these regions on drag, lift, and lateral forces acting on spherical particles at different exposure levels, specifically investigating the contribution of spanwise inhomogeneities. Numerical simulations of turbulent open-channel flow with varying aspect ratios over single-sized spherical particles were conducted, revealing large-scale secondary flows in between the particles and backflow at the trailing edge. It was also observed that drag forces are higher in high-momentum-path regions due to larger streamwise pressure gradients.
Article
Ecology
Zhen Wang, Juan Cao, Fei Cheng, Hubert Keckeis, Songguang Xie
Summary: Inshore habitats in large rivers have a crucial role in the downstream drift of larval fish. The degradation of natural inshore habitats due to shoreline stabilization measures has limited research on the consequences for larval fish condition and distribution. This study investigated the species composition, feeding intensity, and body injuries of larval fish in different inshore habitats along semi-natural and stabilized shores in the middle Yangtze River. Results showed that the abundance, assemblage structure, and body injury rate differed significantly between habitats, with heavily hardened shores having lower species richness and abundance and higher divergence of the assemblage and body injury rates.
Article
Ecology
Sam Brouwer, Paul Humphries, Aleicia Holland, Nicole McCasker
Summary: This study investigated the effects of suspended sediment (SS) concentrations on the clearance and biodeposition rates of the Australian hyriid river mussel Alathyria jacksoni. The results showed that SS concentrations did not significantly affect the clearance rates of algae, but had a significant effect on the clearance of sediment and the production of biodeposits. The study also estimated the potential impact mussel populations have in the clearance of total suspended matter from the open water of a river.
FRESHWATER BIOLOGY
(2023)
