Article
Biodiversity Conservation
Sebastian Schwindt, Beatriz Negreiros, Maria Ponce, Isabella Schalko, Simone Lassar, Ricardo Barros, Stefan Haun
Summary: Rivers provide dynamic habitats, but fine sediment deposition can clog the riverbed matrix and impair ecological functionality. This study introduces a novel fuzzy-logic method to assess clogging and stream restoration effectiveness. Placing large wood can reduce clogging to some extent.
ECOLOGICAL INDICATORS
(2023)
Article
Ecology
Victoria S. Milner, J. Iwan Jones, Ian P. Maddock, George C. Bunting
Summary: This study demonstrates the importance of the hyporheic zone as a refuge for benthic invertebrates during fine sediment disturbance events. It also shows that movement pathways within subsurface sediments are still accessible and allow bidirectional migration between the benthic and hyporheic zone in coarse and colmated sediments.
Article
Engineering, Civil
Guangqiu Jin, Haiyu Yuan, Guangming Zhang, Zhongtian Zhang, Chen Chen, Hongwu Tang, Ling Li
Summary: This study investigates the factors influencing hyporheic exchange by altering the geometric characteristics of the streambed. The results show that hyporheic exchange is stronger in wave-like bedforms compared to triangular bedforms, and increasing the bed height accelerates hyporheic exchange processes. A linear relationship is also found between the depth and area of the hyporheic zone.
JOURNAL OF HYDRO-ENVIRONMENT RESEARCH
(2022)
Article
Environmental Sciences
S. Shrivastava, M. J. Stewardson, M. Arora
Summary: This study examines how the interaction between model organisms and fine sediment deposits affects hyporheic exchange flows in streambeds, finding that the modification of these flows depends on the overall reworking of the beds by organisms. The results demonstrate that the presence of organisms can lead to greater solute penetration depth, shorter residence times, and higher hyporheic exchange flux in stream ecosystems.
WATER RESOURCES RESEARCH
(2021)
Article
Environmental Sciences
Saubhagya S. Rathore, Ahmad Jan, Ethan T. Coon, Scott L. Painter
Summary: This study explores reliable parameter estimations from nonreacting tracer tests monitored at multiple locations, highlighting the importance of the choice of forward and inverse modeling frameworks and data quality for parameter identifiability. Using a new multiscale approach, reliable parameter estimates were successfully obtained.
WATER RESOURCES RESEARCH
(2021)
Article
Environmental Sciences
Laura E. Coulson, Eva Feldbacher, Beate Pitzl, Gabriele Weigelhofer
Summary: This study evaluated the response of temperate stream biofilms to intermittency by sampling different types of streams in Austria. The findings suggest that the history of intermittency does not affect the biofilm response to drought, while factors such as grain size, seasonal growth, and nutrient levels have a larger impact.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Victoria S. Milner, Ian P. Maddock, Iwan Jones, George C. Bunting
Summary: The deposition of excess fine sediment affects macroinvertebrate drift and community dynamics, with higher sediment concentrations causing rapid responses in drifting macroinvertebrates. Sediment characteristics play a role in ecological impairment, but do not affect macroinvertebrate behavioral responses to the fine sediment pulse as expected.
Article
Biodiversity Conservation
Juergen Geist, Rebecca Hoess, Johan Rytterstam, Hakan Soederberg
Summary: Functional and oxygenated riverbeds are important habitats for endangered stream species. Stream bed restoration measures, such as substrate raking, can improve habitat quality by decreasing substrate compaction and increasing oxygen supply. This study found that the effects of restoration measures can last for at least two years, making them a useful long-lasting measure, especially in streams with limited fine sediment input and near-natural flow regimes.
Review
Geosciences, Multidisciplinary
Beth Mondon, David A. Sear, Adrian L. Collins, Peter J. Shaw, Tim Sykes
Summary: Fine sediment plays a critical role in river ecosystems, but excessive fine sediment can have detrimental impacts. Current sediment targets are often oversimplified and may not effectively guide management interventions. Chalk stream catchments are groundwater-dominated systems with unique responses to fine sediment.
Article
Marine & Freshwater Biology
Michal Bily, Ondrej Simon, Vojtech Barak, Vaclava Jahelkova
Summary: The study found that 1-year-old freshwater pearl mussel juveniles have a preference for sediment depth, tending to accumulate in very shallow depths during the summer and avoiding staying on the sediment surface. Experimental results showed that different substrate oxygenation levels were closely related to the survival rates of the juveniles.
Article
Environmental Sciences
Yan Ping Lian, Jonathan Dallmann, Benjamin Sonin, Kevin R. Roche, Aaron Packman, Wing Kam Liu, Gregory J. Wagner
Summary: The study investigates turbulent hyporheic exchange and porewater transport over and through a rough bed of spheres using large eddy simulation (LES). The results show that the interaction between large-scale freestream structures and vortices at the surfaces of individual spheres control turbulent momentum fluxes into the bed, with the transition between turbulent flow and Darcy flow occurring over the first row of spheres.
WATER RESOURCES RESEARCH
(2021)
Article
Environmental Sciences
Arman Haddadchi, Calvin W. Rose
Summary: Interpreting the links between fine sediment storage and suspended sediment transport during flood events is crucial for understanding river geomorphology and the impacts on water quality and bed habitats. A physically based model of suspended sediment transport, coupled with fine sediment deposition and re-entrainment processes within the gravel bed, is presented. The model provides valuable information on the dynamics of fine sediment and its effects on river bed changes. Testing the model with data from flood events in the Oreti River in New Zealand shows good agreement between observed and modeled fine sediment concentration and load. The model can be used for routing suspended sediment concentration and changes in fine sediment deposition in river networks.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Huan Yang, Hosein Foroutan
Summary: In this study, Computational Fluid Dynamics (CFD) simulations were used to investigate the impact of hyporheic exchange on the transport and fate of microplastics in streams. The results show that hyporheic exchange flow significantly influences the behavior and movement of small and light-weighted microplastics, especially near the sediment-water interface. Changes in bed porosity, flow conditions, and bedform morphology have a pronounced effect on the vertical exchange of microplastics. Sweep-ejection events near the bed surface serve as a mechanism for microplastics transport in rivers.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Geography, Physical
Daisuke Harada, Shinji Egashira, Tanjir Saif Ahmed, Hiroyuki Ito
Summary: This paper proposes a new method to evaluate the erosion rate of a sediment bed composed of very fine material. A series of flume experiments were conducted to investigate different factors' influence on erosion rates. The results show that the erosion rate is proportional to the inverse of the overall Richardson number and a modified Richardson number can be used in cases with strong cohesion.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Article
Environmental Sciences
Aleksandra Hagberg, Shashank Gupta, Olena Rzhepishevska, Jerker Fick, Mette Burmolle, Madeleine Ramstedt
Summary: Low concentrations of pharmaceutical substances in the environment may have effects on biological systems, such as bacterial consortia living on riverbed substrates. A study conducted in Sweden found 19 different pharmaceuticals in water downstream from a sewage treatment plant, with differences observed in microbial composition between samples upstream and downstream.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Joachim Pander, Roser Casas-Mulet, Juergen Geist
Summary: This study examines the effects of hydropeaking on upstream tributaries in the Danube River, finding that it leads to significantly higher mortality rates for brown trout eggs and larvae, as well as altering the quality of spawning grounds.
RIVER RESEARCH AND APPLICATIONS
(2023)
Article
Plant Sciences
Tina Koehler, Carolin Schaum, Shu-Yin Tung, Franziska Steiner, Nicolas Tyborski, Andreas J. Wild, Asegidew Akale, Johanna Pausch, Tillmann Lueders, Sebastian Wolfrum, Carsten W. Mueller, Alix Vidal, Wouter K. Vahl, Jennifer Groth, Barbara Eder, Mutez A. Ahmed, Andrea Carminati
Summary: This study investigates the impact of plant hydraulic traits on stomatal regulation in maize during soil drying. The results demonstrate the importance of belowground hydraulics for stomatal regulation and suggest that stomata close when soil hydraulic conductivity drops.
Article
Soil Science
Adina Rauscher, Nele Meyer, Aileen Jakobs, Ryan Bartnick, Tillmann Lueders, Eva Lehndorff
Summary: Plastic input to the terrestrial environment is a global concern, and the effect of microplastics on soil CO2 emissions and microbial biomass has been investigated. It was found that biodegradable microplastics can significantly increase CO2 emissions and microbial biomass in sandy loam soil.
APPLIED SOIL ECOLOGY
(2023)
Review
Biodiversity Conservation
David C. Aldridge, Isobel S. Ollard, Yulia Bespalaya, Ivan N. Bolotov, Karel Douda, Juergen Geist, Wendell R. Haag, Michael W. Klunzinger, Manuel Lopes-Lima, Musa C. Mlambo, Nicoletta Riccardi, Ronaldo Sousa, David L. Strayer, Santiago H. Torres, Caryn C. Vaughn, Tadeusz Zajac, Alexandra Zieritz
Summary: The article identifies 14 emerging and poorly understood threats and opportunities for the global conservation of freshwater mussels over the next decade. These 14 priority topics fall into five broad themes and cover various aspects ranging from autecology to ecosystem services. The prioritization of these topics can help guide proactive approaches to the conservation of this important group.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Marine & Freshwater Biology
Stefan Ossyssek, Andrea Maria Hofmann, Juergen Geist, Uta Raeder
Summary: This study analyzed diversity patterns of sedimentary, littoral, and planktic diatoms in mountain lakes in the northern European Alps and identified the processes that contribute to these patterns. The study found that factors such as lake area, conductivity, elevation, and water temperature are related to diatom diversity, and different types of diatoms are influenced differently.
Review
Marine & Freshwater Biology
Juergen Geist, Alia Benedict, Andreas H. Dobler, Rebecca Hoess, Philipp Hoos
Summary: Freshwater bivalves play a key role in aquatic ecosystems, but the decline of native species has been accompanied by the increasing presence of non-native species. Understanding the interactions between these groups is crucial for their management, but current knowledge is limited. This review examines the functional interactions, niche overlaps, and distribution patterns of native and non-native bivalves in Europe. It also assesses the efficacy and sustainability of existing management tools for non-native species. The study finds strong interactions and niche overlaps between native and non-native bivalves in Central Europe, with potential impacts on specialized and generalist species. Early detection and preventive measures are effective in limiting the spread of undesired species, but most management methods have unintended consequences for endangered native species. The conservation and restoration of intact bivalve habitats are the most sustainable and resilient approaches to their management.
Article
Ecology
Josef Knott, Melanie Mueller, Joachim Pander, Juergen Geist
Summary: Mitigating the adverse ecological impacts on stream ecosystems caused by hydropower expansion is a major challenge, and physical barriers such as fine screens are commonly installed at turbine inlets to prevent fish entrainment and reduce injury risk. This study investigated the species and size-dependent protection from turbine entrainment provided by different fish protection screens (FPSs) at five hydropower sites. The results showed that many fish species, including smaller individuals, were able to pass through the physical barriers, suggesting that greater consideration should be given to small-sized fish in fish protection concepts at hydropower plants.
ECOLOGICAL ENGINEERING
(2023)
Review
Biodiversity Conservation
Alexander F. Cerwenka, Joerg Brandner, Dimitriy Dashinov, Juergen Geist
Summary: Since the early 1990s, the global spread of the invasive round goby has triggered extensive research worldwide. However, there is still a lack of a common theory explaining the invasion success, especially in round goby. To better understand and manage aquatic invasions, it is proposed to strengthen the network of goby researchers and establish long-term databases based on continuous and harmonized monitoring.
Article
Fisheries
Jorrit Lucas, Albert Ros, Juergen Geist, Alexander Brinker
Summary: This study investigated the interaction between northern pike with different behavioral strategies and natural/artificial baits in simulated angling experiments. The results showed that pike exhibit individual differences in their responses to environmental changes, with proactive predators being more likely to be caught during angling. The study also found that angling did not significantly impact the hunting behavior of pike for live prey.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2023)
Article
Green & Sustainable Science & Technology
Josef Knott, Melanie Mueller, Joachim Pander, Juergen Geist
Summary: Efforts to promote renewable energy and reduce negative impacts of hydropower have led to the development of new hydropower technologies. However, a study on an innovative hydropower plant found that the expected advantages in fish protection and river continuity were not achieved. Further research is needed to optimize these concepts.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Environmental Sciences
Romy Wild, Christoffer Nagel, Juergen Geist
Summary: Climate change threatens freshwater fish species due to changes in thermal, sedimentary and hydrological properties of stream ecosystems. Gravel-spawning fish are particularly vulnerable to these changes, as warming, increased sediment and low-flow can negatively impact their reproductive habitat. Multiple stressors can interact synergistically or antagonistically, leading to unexpected effects. This study aimed to assess the individual and combined effects of warming, sediment, and low-flow on hatching success and embryonic development in three fish species. The results showed that fine sediment had the most significant negative effect, and when combined with other stressors, synergistic responses were observed, especially in salmonid species.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Biodiversity Conservation
Juergen Geist, Rebecca Hoess, Johan Rytterstam, Hakan Soederberg
Summary: Functional and oxygenated riverbeds are important habitats for endangered stream species. Stream bed restoration measures, such as substrate raking, can improve habitat quality by decreasing substrate compaction and increasing oxygen supply. This study found that the effects of restoration measures can last for at least two years, making them a useful long-lasting measure, especially in streams with limited fine sediment input and near-natural flow regimes.
Article
Multidisciplinary Sciences
Dheeraj Kanaparthi, Marko Lampe, Jan-Hagen Krohn, Baoli Zhu, Andreas Klingl, Tillmann Lueders
Summary: This study investigates the life cycle of bacterial protoplasts in their natural environment and discovers that their reproduction occurs in a defined sequence of steps, influenced by environmental conditions.
Article
Environmental Sciences
Franziska Bauer, Immanuel Wolfschlaeger, Juergen Geist, Jutta Fastner, Carina Wiena Schmalz, Uta Raeder
Summary: This study analyzed the benthic and planktic forms of cyanobacterial communities in 34 lakes in Germany. It found that 35% of the lakes had benthic mats consisting mainly of Nostocales and Oscillatoriales. The most abundant cyanotoxin in benthic samples was Anatoxin, while microcystin was predominant in open-water samples. These findings suggest the need to strengthen monitoring of benthic cyanobacteria and their toxins.
Article
Environmental Sciences
Noe Ferreira-Rodriguez, Sebastian Beggel, Juergen P. Geist, Vanessa Modesto, Martin Osterling, Nicoletta Riccardi, Ronaldo Sousa, Maria Urbanska
Summary: In the context of the EU Drinking Water Directive, freshwater mussels can assist in addressing the challenges of safe drinking water provisions through the implementation of high frequency noninvasive valvometers. Real-time behavioral analysis is currently being used in several EU countries, and new technological advances are expected to further enhance the potential of HFNI valvometers.
