This page has only limited features, please log in for full access.
Securing genetic integrity is of key importance in conservation-oriented captive breeding programs releasing juveniles into the wild. This is particularly true for species such as the endangered freshwater pearl mussel (Margaritifera margaritifera) for which a number of captive breeding facilities has been established in Europe. The core objective of this study was to compare the genetic constitution of 29 cohorts of captive-bred freshwater pearl mussels from five different breeding facilities in Austria, France, Luxembourg and Germany, with their original 14 source populations from nine major European drainages, based on microsatellite markers. Captive-bred mussels represented 11 different genetic clusters, suggesting an important contribution of the breeding stations to securing the genetic diversity of the species. In almost all cases, the cultured offspring closely resembled the genetic constitution of the source mussels as revealed from the STRUCTURE analysis and the generally high assignment of offspring to the original source populations. The majority of captive-bred cohorts had an increased inbreeding coefficient and decreased genetic variability compared to their source populations as measured by AR and HO. Highest numbers of deformed juveniles coincided with very low levels of HO < 0.05. Since erosion of genetic diversity in captive breeding was mostly evident in individual year-cohorts, long-term breeding over multiple years can minimize such effects. The systematic selection of priority populations for conservation, effective breeding strategies avoiding effects of in- and outbreeding by genetically informed selection of parent individuals, and a network of collaboration among the different breeding facilities would be very useful to increase resilience and effectiveness.
Juergen Geist; Helmut Bayerl; Bernhard C. Stoeckle; Ralph Kuehn. Securing genetic integrity in freshwater pearl mussel propagation and captive breeding. Scientific Reports 2021, 11, 1 .
AMA StyleJuergen Geist, Helmut Bayerl, Bernhard C. Stoeckle, Ralph Kuehn. Securing genetic integrity in freshwater pearl mussel propagation and captive breeding. Scientific Reports. 2021; 11 ():1.
Chicago/Turabian StyleJuergen Geist; Helmut Bayerl; Bernhard C. Stoeckle; Ralph Kuehn. 2021. "Securing genetic integrity in freshwater pearl mussel propagation and captive breeding." Scientific Reports 11, no. : 1.
Fish larval drift is an essential step in the life cycle of riverine fish species as it determines dispersal and colonisation. Anthropogenic flow alterations and interruption of longitudinal and lateral connectivity by river damming and straightening can severely affect larval drift patterns. In this study, we characterised spatio-temporal drift patterns of fish larvae in the heavily regulated large alpine River Inn and within a constructed nature-like fish bypass. Drift was investigated in the main reproduction period of the fish fauna in this river, ranging from mid-April to end of June. Diel patterns were assessed by samples taken during day, dusk, night, and dawn each day of sampling. To obtain robust species identification, we used DNA barcoding for genetic verification of phenotypically pre-sorted groups. From a total of 1,069 fish larvae and 283 fish eggs caught, DNA barcoding revealed 16 species from five families, including several target species of conservation. We found strong evidence that several endangered species, such as Chondrostoma nasus, Thymallus thymallus, Cottus gobio, and Aspius aspius successfully reproduced in the bypass system. Genetic species verification showed a high level of homogeneity in most phenotypically pre-sorted groups. Distinct seasonal patterns were observed, with the majority of fish species in the drift observed in mid-June. Thymallus thymallus and Cottus gobio dominated larval drift at the beginning of the observation followed by mainly unimodal abundance peaks of several Cyprinid species. Nocturnal drift prevailed in all species. Our results on the spatial occurrence and abundances of fish larvae highlight the importance of bypass systems in heavily modified waterbodies to provide valuable spawning habitats and drift corridors around dams. Moreover, the distinct species-specific time patterns of larval drift represent a first basis to direct future discharge and river management plans in large alpine rivers towards a protection of the sensitive larval stages of specific target species of conservation. This includes bypass and turbine operation modes in the period of highest drift activity, as well as the construction of nature-like bypass systems and creation of spawning grounds therein.
Christoffer Nagel; Melanie Mueller; Joachim Pander; Bernhard C. Stoeckle; Ralph Kuehn; Juergen Geist. Going with the flow: Spatio‐temporal drift patterns of larval fish in a large alpine river. Freshwater Biology 2021, 66, 1765 -1781.
AMA StyleChristoffer Nagel, Melanie Mueller, Joachim Pander, Bernhard C. Stoeckle, Ralph Kuehn, Juergen Geist. Going with the flow: Spatio‐temporal drift patterns of larval fish in a large alpine river. Freshwater Biology. 2021; 66 (9):1765-1781.
Chicago/Turabian StyleChristoffer Nagel; Melanie Mueller; Joachim Pander; Bernhard C. Stoeckle; Ralph Kuehn; Juergen Geist. 2021. "Going with the flow: Spatio‐temporal drift patterns of larval fish in a large alpine river." Freshwater Biology 66, no. 9: 1765-1781.
Bank habitats provide important functions for riverine fish. Yet, they have been heavily modified by land use, technical flood protection measures, and hydropower installations. Fish species requiring specific habitats to complete their life cycle have strongly declined and therefore become target species of river restoration measures. This study compared abiotic conditions and fish community composition of three bank habitat types in a large alpine river, comprising different degrees of alteration compared to the natural state (concrete profile, bank riprap, and naturally restored riverbank). Significant differences in abiotic habitat characteristics such as bed material, water depth, turbidity, submerged vegetation, and temperature were detected between the three bank habitat types and sampling seasons. These water level-dependent structural changes had the strongest effect on fish community composition as detected by distance-based linear modeling. Small specimens between 3 and 13 cm TL and juveniles were most abundant in the restored areas, except for Lota lota, which was most abundant in the man-made bank riprap. Target species of conservation were mostly detected in restored areas, particularly the critical young life stages of Chondrostoma nasus, Barbus barbus, and Thymallus thymallus. Water level strongly determined accessibility and suitability of bank habitats, with shallow, gravel-dominated habitats comprising flat bank angles being most beneficial for these species. The findings of this study provide evidence for the success of bank habitat restoration in structurally impacted alpine rivers on target species of conservation. Fluctuating water levels and discharges typical for alpine rivers should be better considered in restoration planning, particularly in light of climate change, affecting the timing and amplitude of discharge in these systems.
Joachim Pander; Christoffer Nagel; Hannah Ingermann; Juergen Geist. Water level induced changes of habitat quality determine fish community composition in restored and modified riverbanks of a large alpine river. International Review of Hydrobiology 2021, 1 .
AMA StyleJoachim Pander, Christoffer Nagel, Hannah Ingermann, Juergen Geist. Water level induced changes of habitat quality determine fish community composition in restored and modified riverbanks of a large alpine river. International Review of Hydrobiology. 2021; ():1.
Chicago/Turabian StyleJoachim Pander; Christoffer Nagel; Hannah Ingermann; Juergen Geist. 2021. "Water level induced changes of habitat quality determine fish community composition in restored and modified riverbanks of a large alpine river." International Review of Hydrobiology , no. : 1.
Scanning electron microscopy (SEM) has been widely used to describe interspecific differences in egg quality of teleost freshwater fish, but potential intraspecific differences are poorly studied. Eggs of many rheophilic cyprinids are covered with adhesive structures such as attaching villi facilitating egg attachment at substrates of spawning grounds with high currents. Recent findings indicate that the egg quality of the rheophilic cyprinid common nase (Chondrostoma nasus L.), a target species of conservation, differs in the adhesiveness between spawning populations, potentially explaining differences in recruitment success. In this study, a SEM image-based standardized protocol was established to assess egg surface quality of Chondrostoma nasus eggs. Multivariate statistics detected significant differences of egg surface properties among individual females and among three 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. The findings of this study highlight the need for further investigations to better understand the relationship of egg surface properties, egg stickiness and hatching success to understand the recruitment ecology and performance of early life stages in freshwater fish.
Christoffer Nagel; Christina Spiessl; Joachim Pander; Juergen Geist. SEM images reveal intraspecific differences in egg surface properties of common nase ( Chondrostoma nasus L.). Journal of Applied Ichthyology 2021, 1 .
AMA StyleChristoffer Nagel, Christina Spiessl, Joachim Pander, Juergen Geist. SEM images reveal intraspecific differences in egg surface properties of common nase ( Chondrostoma nasus L.). Journal of Applied Ichthyology. 2021; ():1.
Chicago/Turabian StyleChristoffer Nagel; Christina Spiessl; Joachim Pander; Juergen Geist. 2021. "SEM images reveal intraspecific differences in egg surface properties of common nase ( Chondrostoma nasus L.)." Journal of Applied Ichthyology , no. : 1.
Juergen Geist. Editorial: Green or red: Challenges for fish and freshwater biodiversity conservation related to hydropower. Aquatic Conservation: Marine and Freshwater Ecosystems 2021, 31, 1551 -1558.
AMA StyleJuergen Geist. Editorial: Green or red: Challenges for fish and freshwater biodiversity conservation related to hydropower. Aquatic Conservation: Marine and Freshwater Ecosystems. 2021; 31 (7):1551-1558.
Chicago/Turabian StyleJuergen Geist. 2021. "Editorial: Green or red: Challenges for fish and freshwater biodiversity conservation related to hydropower." Aquatic Conservation: Marine and Freshwater Ecosystems 31, no. 7: 1551-1558.
Increased deposition of fine sediments in rivers and streams affects a range of key ecosystem processes across the sediment–water interface, and it is a critical aspect of river habitat degradation and restoration. Understanding the mechanisms leading to fine sediment accumulation along and across streambeds and their effect on ecological processes is essential for comprehending human impacts on river ecosystems and informing river restoration. Here, we introduce the HydroEcoSedimentary tool (HEST) as an integrated approach to assess hydro-sedimentary and ecologically relevant processes together. The HEST integrates the estimation of sedimentary processes in the interstitial zone, as well as hydraulic, geochemical and ecological assessments, with a focus on brown trout early life stages. Compared to other methods, the HEST expands the possibilities to monitor and quantify fine sediment deposition in streambeds by differentiating between vertical, lateral and longitudinal infiltration pathways, and distinguishing between the depth (upper vs. lower layers) at which interstitial processes occur within the sediment column. By testing the method in two rivers with different degrees of morphological degradation, we detail the possible measurements and uses of the HEST, demonstrate its feasibility and discuss its reliability.
Roser Casas‐Mulet; Joachim Pander; Maximilian Prietzel; Juergen Geist. The HydroEcoSedimentary tool: An integrated approach to characterise interstitial hydro‐sedimentary and associated ecological processes. River Research and Applications 2021, 1 .
AMA StyleRoser Casas‐Mulet, Joachim Pander, Maximilian Prietzel, Juergen Geist. The HydroEcoSedimentary tool: An integrated approach to characterise interstitial hydro‐sedimentary and associated ecological processes. River Research and Applications. 2021; ():1.
Chicago/Turabian StyleRoser Casas‐Mulet; Joachim Pander; Maximilian Prietzel; Juergen Geist. 2021. "The HydroEcoSedimentary tool: An integrated approach to characterise interstitial hydro‐sedimentary and associated ecological processes." River Research and Applications , no. : 1.
The global decline of freshwater bivalves (Unionida) has prompted many programmes for their conservation and augmentation, which often include a captive breeding component. One key point to such programmes is the collection, maintenance and use of mussel glochidium larvae, which require attachment to a fish host in a sensitive parasitic stage of their life cycle. Understanding the thermal limits of glochidia can increase knowledge of mussel larval survival and ultimately aid in the development of conservation programmes. Glochidia of the endangered thick-shelled river mussel Unio crassus and the non-native Chinese pond mussel Sinanodonta woodiana were observed for active clamping ability at 5, 15, 17, 20 and 25 °C over the course of a 7-d period. The results from this study confirm that an inverse relationship between water temperature and larval viability can be observed in both species. Additionally, the significantly higher thermal tolerance of S. woodiana indicates that the species exhibits competitive invasive behaviour beginning from the larval stage. These findings also suggest that the collection and transportation of glochidia from genetically important yet distant populations is feasible if the larvae can be maintained at temperatures between 5 and 15 °C.
Alia Benedict; Juergen Geist. Effects of water temperature on glochidium viability of Unio crassus and Sinanodonta woodiana: implications for conservation, management and captive breeding. Journal Of Molluscan Studies 2021, 87, 1 .
AMA StyleAlia Benedict, Juergen Geist. Effects of water temperature on glochidium viability of Unio crassus and Sinanodonta woodiana: implications for conservation, management and captive breeding. Journal Of Molluscan Studies. 2021; 87 (2):1.
Chicago/Turabian StyleAlia Benedict; Juergen Geist. 2021. "Effects of water temperature on glochidium viability of Unio crassus and Sinanodonta woodiana: implications for conservation, management and captive breeding." Journal Of Molluscan Studies 87, no. 2: 1.
Fish passes facilitate fish movement in fragmented river systems, yet they can also provide important habitat functions. This study investigated the fish community composition of different constructed habitat types (fluvial habitats, floodplain ponds) within fish passes in relation to habitat characteristics in order to deduce recommendations for fish-friendly designs of such structures. Fish community structures within passes differed significantly from those in the main river, comprising a high number of rheophilic species in fluvial habitats (Thymallus thymallus, Hucho hucho, Salmo trutta, Cottus gobio, Chondrostoma nasus, and Barbus barbus), and of stagnophilic species in floodplain ponds (Rhodeus amarus, Scardinius erythrophthalmus, Misgurnus bipartitus, and Tinca tinca). During summer, floodplain ponds also provided important juvenile habitats for the target species C. nasus and B. barbus. Differences between the two habitat types in fish abundance were mostly explained by differences in macrophyte coverage, gravel, boulders, temperature, and current speed. The findings of this study stress the important habitat functions of fish passes. They also suggest that integration of diverse habitat structures, especially of currently hardly considered constructed floodplain ponds into fish passes, can greatly enhance their fish communities and contribute to the restoration of several declining target species of conservation.
Joachim Pander; Christoffer Nagel; Juergen Geist. Integration of Constructed Floodplain Ponds into Nature-Like Fish Passes Supports Fish Diversity in a Heavily Modified Water Body. Water 2021, 13, 1018 .
AMA StyleJoachim Pander, Christoffer Nagel, Juergen Geist. Integration of Constructed Floodplain Ponds into Nature-Like Fish Passes Supports Fish Diversity in a Heavily Modified Water Body. Water. 2021; 13 (8):1018.
Chicago/Turabian StyleJoachim Pander; Christoffer Nagel; Juergen Geist. 2021. "Integration of Constructed Floodplain Ponds into Nature-Like Fish Passes Supports Fish Diversity in a Heavily Modified Water Body." Water 13, no. 8: 1018.
Understanding stream thermal heterogeneity patterns is crucial to assess and manage river resilience in light of climate change. The dual acquisition of high-resolution thermal infrared (TIR) and red–green–blue-band (RGB) imagery from unmanned aerial vehicles (UAVs) allows for the identification and characterization of thermally differentiated patches (e.g., cold-water patches—CWPs). However, a lack of harmonized CWP classification metrics (patch size and temperature thresholds) makes comparisons across studies almost impossible. Based on an existing dual UAV imagery dataset (River Ovens, Australia), we present a semi-automatic supervised approach to classify key riverscape habitats and associated thermal properties at a pixel-scale accuracy, based on spectral properties. We selected five morphologically representative reaches to (i) illustrate and test our combined classification and thermal heterogeneity assessment method, (ii) assess the changes in CWP numbers and distribution with different metric definitions, and (iii) model how climatic predictions will affect thermal habitat suitability and connectivity of a cold-adapted fish species. Our method was successfully tested, showing mean thermal differences between shaded and sun-exposed fluvial mesohabitats of up to 0.62 °C. CWP metric definitions substantially changed the number and distance between identified CWPs, and they were strongly dependent on reach morphology. Warmer scenarios illustrated a decrease in suitable fish habitats, but reach-scale morphological complexity helped sustain such habitats. Overall, this study demonstrates the importance of method and metric definitions to enable spatio-temporal comparisons between stream thermal heterogeneity studies.
Johannes Kuhn; Roser Casas-Mulet; Joachim Pander; Juergen Geist. Assessing Stream Thermal Heterogeneity and Cold-Water Patches from UAV-Based Imagery: A Matter of Classification Methods and Metrics. Remote Sensing 2021, 13, 1379 .
AMA StyleJohannes Kuhn, Roser Casas-Mulet, Joachim Pander, Juergen Geist. Assessing Stream Thermal Heterogeneity and Cold-Water Patches from UAV-Based Imagery: A Matter of Classification Methods and Metrics. Remote Sensing. 2021; 13 (7):1379.
Chicago/Turabian StyleJohannes Kuhn; Roser Casas-Mulet; Joachim Pander; Juergen Geist. 2021. "Assessing Stream Thermal Heterogeneity and Cold-Water Patches from UAV-Based Imagery: A Matter of Classification Methods and Metrics." Remote Sensing 13, no. 7: 1379.
Since historical times, the inherent human fascination with pearls turned the freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) into a highly valuable cultural and economic resource. Although pearl harvesting in M. margaritifera is nowadays residual, other human threats have aggravated the species conservation status, especially in Europe. This mussel presents a myriad of rare biological features, e.g. high longevity coupled with low senescence and Doubly Uniparental Inheritance of mitochondrial DNA, for which the underlying molecular mechanisms are poorly known. Here, the first draft genome assembly of M. margaritifera was produced using a combination of Illumina Paired-end and Mate-pair approaches. The genome assembly was 2.4 Gb long, possessing 105,185 scaffolds and a scaffold N50 length of 288,726 bp. The ab initio gene prediction allowed the identification of 35,119 protein-coding genes. This genome represents an essential resource for studying this species’ unique biological and evolutionary features and ultimately will help to develop new tools to promote its conservation.
André Gomes-Dos-Santos; Manuel Lopes-Lima; André M Machado; António Marcos Ramos; Ana Usié; Ivan N Bolotov; Ilya V Vikhrev; Sophie Breton; L Filipe C Castro; Rute R da Fonseca; Juergen Geist; Martin E Österling; Vincent Prié; Amílcar Teixeira; Han Ming Gan; Oleg Simakov; Elsa Froufe. The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758). DNA Research 2021, 28, 1 .
AMA StyleAndré Gomes-Dos-Santos, Manuel Lopes-Lima, André M Machado, António Marcos Ramos, Ana Usié, Ivan N Bolotov, Ilya V Vikhrev, Sophie Breton, L Filipe C Castro, Rute R da Fonseca, Juergen Geist, Martin E Österling, Vincent Prié, Amílcar Teixeira, Han Ming Gan, Oleg Simakov, Elsa Froufe. The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758). DNA Research. 2021; 28 (2):1.
Chicago/Turabian StyleAndré Gomes-Dos-Santos; Manuel Lopes-Lima; André M Machado; António Marcos Ramos; Ana Usié; Ivan N Bolotov; Ilya V Vikhrev; Sophie Breton; L Filipe C Castro; Rute R da Fonseca; Juergen Geist; Martin E Österling; Vincent Prié; Amílcar Teixeira; Han Ming Gan; Oleg Simakov; Elsa Froufe. 2021. "The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758)." DNA Research 28, no. 2: 1.
Anthropogenic freshwater habitats may provide undervalued prospects for long‐term conservation as part of species conservation planning. This fundamental, but overlooked, issue requires attention considering the pace that humans have been altering natural freshwater ecosystems and the accelerated levels of biodiversity decline in recent decades. We compiled 709 records of freshwater mussels (Bivalvia, Unionida) inhabiting a broad variety of anthropogenic habitat types (from small ponds to large reservoirs and canals) and reviewed their importance as refuges for this faunal group. Most records came from Europe and North America, with a clear dominance of canals and reservoirs. The dataset covered 228 species, including 34 threatened species on the IUCN Red List. We discuss the conservation importance and provide guidance on how these anthropogenic habitats could be managed to provide optimal conservation value to freshwater mussels. This review also shows that some of these habitats may function as ecological traps owing to conflicting management practices or because they act as a sink for some populations. Therefore, anthropogenic habitats should not be seen as a panacea to resolve conservation problems. More information is necessary to better understand the trade‐offs between human use and the conservation of freshwater mussels (and other biota) within anthropogenic habitats, given the low number of quantitative studies and the strong biogeographic knowledge bias that persists.
Ronaldo Sousa; Dariusz Halabowski; Anna M. Labecka; Karel Douda; Olga Aksenova; Yulia Bespalaya; Ivan Bolotov; Juergen Geist; Hugh A. Jones; Ekaterina Konopleva; Michael W. Klunzinger; Carlos A. Lasso; Iga Lewin; Xiongjun Liu; Manuel Lopes‐Lima; Jon Mageroy; Musa Mlambo; Keiko Nakamura; Mitsunori Nakano; Martin Österling; John Pfeiffer; Vincent Prié; Lucas R. P. Paschoal; Nicoletta Riccardi; Rogério Santos; Spase Shumka; Allan K. Smith; Mikhail O. Son; Amílcar Teixeira; Frankie Thielen; Santiago Torres; Simone Varandas; Ilya V. Vikhrev; Xiaoping Wu; Alexandra Zieritz; Joana G. Nogueira. The role of anthropogenic habitats in freshwater mussel conservation. Global Change Biology 2021, 27, 2298 -2314.
AMA StyleRonaldo Sousa, Dariusz Halabowski, Anna M. Labecka, Karel Douda, Olga Aksenova, Yulia Bespalaya, Ivan Bolotov, Juergen Geist, Hugh A. Jones, Ekaterina Konopleva, Michael W. Klunzinger, Carlos A. Lasso, Iga Lewin, Xiongjun Liu, Manuel Lopes‐Lima, Jon Mageroy, Musa Mlambo, Keiko Nakamura, Mitsunori Nakano, Martin Österling, John Pfeiffer, Vincent Prié, Lucas R. P. Paschoal, Nicoletta Riccardi, Rogério Santos, Spase Shumka, Allan K. Smith, Mikhail O. Son, Amílcar Teixeira, Frankie Thielen, Santiago Torres, Simone Varandas, Ilya V. Vikhrev, Xiaoping Wu, Alexandra Zieritz, Joana G. Nogueira. The role of anthropogenic habitats in freshwater mussel conservation. Global Change Biology. 2021; 27 (11):2298-2314.
Chicago/Turabian StyleRonaldo Sousa; Dariusz Halabowski; Anna M. Labecka; Karel Douda; Olga Aksenova; Yulia Bespalaya; Ivan Bolotov; Juergen Geist; Hugh A. Jones; Ekaterina Konopleva; Michael W. Klunzinger; Carlos A. Lasso; Iga Lewin; Xiongjun Liu; Manuel Lopes‐Lima; Jon Mageroy; Musa Mlambo; Keiko Nakamura; Mitsunori Nakano; Martin Österling; John Pfeiffer; Vincent Prié; Lucas R. P. Paschoal; Nicoletta Riccardi; Rogério Santos; Spase Shumka; Allan K. Smith; Mikhail O. Son; Amílcar Teixeira; Frankie Thielen; Santiago Torres; Simone Varandas; Ilya V. Vikhrev; Xiaoping Wu; Alexandra Zieritz; Joana G. Nogueira. 2021. "The role of anthropogenic habitats in freshwater mussel conservation." Global Change Biology 27, no. 11: 2298-2314.
The biological communities of mountain lakes are suspected to be highly sensitive to global warming and associated catchment changes. To identify the parameters determining algal community responses, subfossil pigments from 21 different mountain lakes in the Bavarian‐Tyrolean Limestone Alps were investigated. Sediment cores were radio‐isotopically dated, and their pigment preservation evaluated. General additive models (GAM) of pigment compositions were calculated with temperature as the explanatory variable and generalised linear models with several lake parameters explaining log‐transformed GAM p‐values. Lake depth and trophic state were identified as major control variables of the algal community and productivity changes. Shifts in a deep oligotrophic alpine lake (lg(p) = –1.04) were half as strong as in a shallow mesotrophic alpine lake (lg(p) = –1.86) with faster warming and higher productivity forcing the development of biomass. Phytoplankton and macrophyte pigments increased clearly with warming, at lower altitudes, and decreased at the treeline, so that periphytic pigments dominated alpine sediments. This pattern is probably the result of interactions of UV radiation and allochthonous inputs of DOM. Our findings suggest that (sub)alpine shallow lakes with higher nutrient levels are most vulnerable to climate change‐driven changes whereas deep, nutrient‐poor lakes appear more resilient.
Wolfgang Kuefner; Andrea M. Hofmann; Juergen Geist; Natalie Dubois; Uta Raeder. Algal Community Change in Mountain Lakes of the Alps Reveals Effects of Climate Warming and Shifting Treelines 1. Journal of Phycology 2021, 57, 1266 -1283.
AMA StyleWolfgang Kuefner, Andrea M. Hofmann, Juergen Geist, Natalie Dubois, Uta Raeder. Algal Community Change in Mountain Lakes of the Alps Reveals Effects of Climate Warming and Shifting Treelines 1. Journal of Phycology. 2021; 57 (4):1266-1283.
Chicago/Turabian StyleWolfgang Kuefner; Andrea M. Hofmann; Juergen Geist; Natalie Dubois; Uta Raeder. 2021. "Algal Community Change in Mountain Lakes of the Alps Reveals Effects of Climate Warming and Shifting Treelines 1." Journal of Phycology 57, no. 4: 1266-1283.
Increased deposition of fine sediments in streams affects a range of key ecosystem processes across the sediment-water interface, and it is a critical aspect of river habitat degradation and restoration. Understanding the mechanisms leading to fine sediment accumulation along and across streambeds, and their affectation to ecological processes is therefore essential for comprehending human impacts on river ecosystems and inform river restoration. Here, we introduce the HydroEcoSedimentary Tool (HEST) as an integrated approach to assess hydro-sedimentary and ecologically relevant processes together. The HEST integrates the estimation of a range of processes occurring in the interstitial zone, including sedimentary (fine sediment accumulation and fine sediment loss upon retrieval), hydraulic (hydraulic conductivity), geochemical (water quality and temperature) and ecological (with a focus on brown trout early life stages).
We tested the HEST application in two rivers with different degrees of morphological degradation in Germany. The HEST was successful in recording the set of key hydrosedimentary and ecologically relevant factors, and in providing a mechanistic linkage between and biological effect in a site-specific context. The HEST data confirmed that salmonid embryo mortality could be linked to high fine deposition in gravel beds. In addition, the HEST illustrated that such mortality could be linked explicitly to interstitial depths and to different infiltration pathways for fines (e.g. vertical vs. horizontal). Although interstitial water quality and temperature were within ecological thresholds and did not show significant differences with surface water, it was still useful to monitor such variables and to rule out any effect on mortality. Water temperature, for example, could be extremely important to detect local groundwater inputs, which has been demonstrated to have a significant effect on embryo salmonids elsewhere. The HEST also allowed accounting for the loss of fines during retrieval failure and estimating hydrological factors with the HEST illustrates its additional usefulness and reliability.
Compared to other methods, the HEST expands the possibilities to monitor and quantify fine sediment deposition in streambeds by differentiating between vertical, lateral and longitudinal infiltration pathways, and distinguishing between the depth (upper vs. lower layers) at which interstitial processes occur along the streambed column.
Roser Casas-Mulet; Joachim Pander; Maximilian Prietzel; Juergen Geist. The HydroEcoSedimentary Tool: an integrated approach to characterise interstitial processes in freshwater systems. 2021, 1 .
AMA StyleRoser Casas-Mulet, Joachim Pander, Maximilian Prietzel, Juergen Geist. The HydroEcoSedimentary Tool: an integrated approach to characterise interstitial processes in freshwater systems. . 2021; ():1.
Chicago/Turabian StyleRoser Casas-Mulet; Joachim Pander; Maximilian Prietzel; Juergen Geist. 2021. "The HydroEcoSedimentary Tool: an integrated approach to characterise interstitial processes in freshwater systems." , no. : 1.
Securing adequate supply of high-quality water is of increasing global importance and relies in large part on ecosystem services provided by freshwater biota. Unionid mussels are important keystone species and habitat engineers that shape freshwater ecosystems through water filtration, nutrient cycling and provision of habitats; their rapid global declines result in dramatic losses of ecosystem functions. Maintenance and enhancement of the services they provide depend on the identification of their crucial habitats. Following theoretical assumptions, this study analyses the importance of lake-stream transition zones for unionid mussels, based on data collected in 1984 and 2019 from an undisturbed stream flowing through five consecutive lakes. Mussel distribution matched the distribution of host fish and was strongly influenced by lakes: densities were highest near lake outlets, reaching 290 ind. m−2 (14.7 kg m−2) in 2019, and declined with downstream distance following a negative power function. This pattern was spatially consistent and sustained over time. All six unionid species native to north-central Europe were present, but common species (Anodonta anatina, Unio pictorum, U. tumidus) contributed about 80% of individuals and were responsible for most of the ecosystem services provided by unionid mussels. Estimated 1.9 × 106 mussel individuals inhabiting 3.2 km of stream length filtered a water volume equivalent to the total stream discharge approximately 2.5 times daily. Aggregations of spent shells, up to 17 kg m−2, accumulated downstream of lakes, forming extensive shell and mussel beds, providing habitats and contributing shell hash that improved stream-bed conditions. Globally invasive Dreissena polymorpha was present at low densities and did not spread or increase in abundance, indicating a long-term biotic resistance of the natural native community. Our study underscores the importance of undisturbed lake outlets, longitudinal connectivity of riverine ecosystems, and of common mussel species in maintaining freshwater ecosystem functionality and provision of vital services.
Małgorzata Ożgo; Maria Urbańska; Magdalena Marzec; Andrzej Kamocki; Wojciech Andrzejewski; Janusz Golski; Krzysztof Lewandowski; Juergen Geist. Lake-stream transition zones support hotspots of freshwater ecosystem services: Evidence from a 35-year study on unionid mussels. Science of The Total Environment 2021, 774, 145114 .
AMA StyleMałgorzata Ożgo, Maria Urbańska, Magdalena Marzec, Andrzej Kamocki, Wojciech Andrzejewski, Janusz Golski, Krzysztof Lewandowski, Juergen Geist. Lake-stream transition zones support hotspots of freshwater ecosystem services: Evidence from a 35-year study on unionid mussels. Science of The Total Environment. 2021; 774 ():145114.
Chicago/Turabian StyleMałgorzata Ożgo; Maria Urbańska; Magdalena Marzec; Andrzej Kamocki; Wojciech Andrzejewski; Janusz Golski; Krzysztof Lewandowski; Juergen Geist. 2021. "Lake-stream transition zones support hotspots of freshwater ecosystem services: Evidence from a 35-year study on unionid mussels." Science of The Total Environment 774, no. : 145114.
Extensive fish production in earthen ponds is a common aquaculture practice, which requires draining of the ponds for fish harvesting. Despite their value for biodiversity and water retention, the impact of fish ponds on the receiving streams as regards fine sediment and nutrient pollution remains controversial. This holds particularly true for streams with endangered freshwater pearl mussels, requiring a highly permeable streambed with low fine sediment content for successful juvenile development. This study quantified the amount of fine sediment, suspended solids and nutrients delivered to pearl mussel streams in relation to the pond characteristics, distance to the receiving stream and applications of measures to prevent the input of fines. Comparing fine sediment deposition above and downstream of the pond inlets after 21 pond drainage operations, as well as continuous measurements of the turbidity for 12 operations revealed varying effects of pond fishing on the receiving streams. Average fine sediment deposition was increased by nearly six-fold compared to upstream and maximum turbidity values for single drainage operations exceeded 460 NTU. Draining between 1% and 92% of the water volume of individual ponds resulted in additional loading of 0.07–4.6 t suspended particles. Physical mitigation structures that prevent mobilized material from reaching the receiving stream significantly reduced the fine sediment input and deposition rates. Harvesting methods that do not require complete drainage of the pond reduced the turbidity by ten-fold. Without mitigation measures, the impact of pond drainage operations on the fine sediment deposition was comparable to high discharge events. No significant increase in nutrient concentration was observed during most drainage operations. These results reveal remarkable effects of pond drainage on the aquatic environment, as well as the possibility to minimize such impacts by switching to harvest methods that do not require complete pond drainage and installation of sedimentation structures.
Rebecca Hoess; Juergen Geist. Effect of fish pond drainage on turbidity, suspended solids, fine sediment deposition and nutrient concentration in receiving pearl mussel streams. Environmental Pollution 2021, 274, 116520 .
AMA StyleRebecca Hoess, Juergen Geist. Effect of fish pond drainage on turbidity, suspended solids, fine sediment deposition and nutrient concentration in receiving pearl mussel streams. Environmental Pollution. 2021; 274 ():116520.
Chicago/Turabian StyleRebecca Hoess; Juergen Geist. 2021. "Effect of fish pond drainage on turbidity, suspended solids, fine sediment deposition and nutrient concentration in receiving pearl mussel streams." Environmental Pollution 274, no. : 116520.
Ecotoxicological effect assessment of particulate materials and sparingly soluble substances (SSS) is an emerging field. Current standard toxicity tests of aquatic organisms are based on soluble substances which are added to the aqueous phase. While soluble substances distribute homogeneously, particles can form aggregates resulting in inhomogeneous distribution and unpredictable exposure. Therefore, test scenarios need to be adapted to overcome these uncertainties. Here we present a dietary particle exposure tool for the toxicity testing of SSS or particles in combination with a standardizable food source for gammarids based on DECOTABs from Kampfraath et al. (2012). Four food supplements in the DEOCOTAB formulation were compared to test their influence on the energy reserves of gammarids. While feeding rate was constant for most supplements, mortality and energy reserves revealed clear differences. Tabs supplemented with algae‐based phyll or animal protein‐based trout food met best all requirements. Fluorescent plastic microparticles (10 to 65 µm) were homogenously distributed and stable in the DECOTABs. Constant feeding was observed and the number of ingested microparticles by Gammarus roeseli was quantified in relation to the consumed food. The developed method provides a realistic and methodologically reliable uptake from the oral pathway and allows the quantification of inner exposition via feeding rate, providing a promising tool for standardized dietary exposure scenarios with particles.
Astrid Götz; Hannes K. Imhof; Juergen Geist; Sebastian Beggel. Moving Toward Standardized Toxicity Testing Procedures with Particulates by Dietary Exposure of Gammarids. Environmental Toxicology and Chemistry 2021, 40, 1463 -1476.
AMA StyleAstrid Götz, Hannes K. Imhof, Juergen Geist, Sebastian Beggel. Moving Toward Standardized Toxicity Testing Procedures with Particulates by Dietary Exposure of Gammarids. Environmental Toxicology and Chemistry. 2021; 40 (5):1463-1476.
Chicago/Turabian StyleAstrid Götz; Hannes K. Imhof; Juergen Geist; Sebastian Beggel. 2021. "Moving Toward Standardized Toxicity Testing Procedures with Particulates by Dietary Exposure of Gammarids." Environmental Toxicology and Chemistry 40, no. 5: 1463-1476.
Monitoring of fish passage at hydropower plants largely relies on stow-fyke-net captures installed downstream of turbine outlets, yet little is known about which fish behavior contributes to reduced catch efficiency. We studied fish-net interactions as well as biological and physical factors potentially influencing behavior in three experiments: (i) fall-through experiment, to measure the general physical ability of a fish to fit through a certain mesh size; (ii) net-perception experiment, where fish were filmed while being exposed to different mesh sizes, flow and lure conditions in a controlled arena setup; and (iii) stow-fyke-net experiment, where fish behavior was recorded using 20 cameras simultaneously inside a stow net during regular hydropower fish monitoring. In total, we analyzed 382 h of video recordings. The material revealed that fish interacted with the net on a high rate, independent of flow conditions, and tried to swim through the mesh regardless of whether their body fits through. Under field conditions, the fish showed three specific behavioral patterns, “sneaking,” “dwelling” and “commuting,” which led to a reduced recapture rate in the catch unit of the stow-fyke net. This study highlights the importance of considering fish behavior in future fish monitoring programs to improve the accuracy of turbine-effect assessments on fish.
Nicole Smialek; Joachim Pander; Arne Heinrich; Juergen Geist. Sneaker, Dweller and Commuter: Evaluating Fish Behavior in Net-Based Monitoring at Hydropower Plants—A Case Study on Brown Trout (Salmo trutta). Sustainability 2021, 13, 669 .
AMA StyleNicole Smialek, Joachim Pander, Arne Heinrich, Juergen Geist. Sneaker, Dweller and Commuter: Evaluating Fish Behavior in Net-Based Monitoring at Hydropower Plants—A Case Study on Brown Trout (Salmo trutta). Sustainability. 2021; 13 (2):669.
Chicago/Turabian StyleNicole Smialek; Joachim Pander; Arne Heinrich; Juergen Geist. 2021. "Sneaker, Dweller and Commuter: Evaluating Fish Behavior in Net-Based Monitoring at Hydropower Plants—A Case Study on Brown Trout (Salmo trutta)." Sustainability 13, no. 2: 669.
A recent global meta‐analysis reported a decrease in terrestrial but increase in freshwater insect abundance and biomass (van Klink et al., Science 368, p. 417). The authors suggested that water quality has been improving, thereby challenging recent reports documenting drastic global declines in freshwater biodiversity. We raise two major concerns with the meta‐analysis and suggest that these account for the discrepancy with the declines reported elsewhere. First, total abundance and biomass alone are poor indicators of the status of freshwater insect assemblages, and the observed differences may well have been driven by the replacement of sensitive species with tolerant ones. Second, many of the datasets poorly represent global trends and reflect responses to local conditions or nonrandom site selection. We conclude that the results of the meta‐analysis should not be considered indicative of an overall improvement in the condition of freshwater ecosystems. This article is categorized under: Water and Life > Conservation, Management, and Awareness
Sonja C. Jähnig; Viktor Baranov; Florian Altermatt; Peter Cranston; Martin Friedrichs‐Manthey; Juergen Geist; Fengzhi He; Jani Heino; Daniel Hering; Franz Hölker; Jonas Jourdan; Gregor Kalinkat; Jens Kiesel; Florian Leese; Alain Maasri; Michael T. Monaghan; Ralf B. Schäfer; Klement Tockner; Jonathan D. Tonkin; Sami Domisch. Revisiting global trends in freshwater insect biodiversity. WIREs Water 2020, 8, 1 .
AMA StyleSonja C. Jähnig, Viktor Baranov, Florian Altermatt, Peter Cranston, Martin Friedrichs‐Manthey, Juergen Geist, Fengzhi He, Jani Heino, Daniel Hering, Franz Hölker, Jonas Jourdan, Gregor Kalinkat, Jens Kiesel, Florian Leese, Alain Maasri, Michael T. Monaghan, Ralf B. Schäfer, Klement Tockner, Jonathan D. Tonkin, Sami Domisch. Revisiting global trends in freshwater insect biodiversity. WIREs Water. 2020; 8 (2):1.
Chicago/Turabian StyleSonja C. Jähnig; Viktor Baranov; Florian Altermatt; Peter Cranston; Martin Friedrichs‐Manthey; Juergen Geist; Fengzhi He; Jani Heino; Daniel Hering; Franz Hölker; Jonas Jourdan; Gregor Kalinkat; Jens Kiesel; Florian Leese; Alain Maasri; Michael T. Monaghan; Ralf B. Schäfer; Klement Tockner; Jonathan D. Tonkin; Sami Domisch. 2020. "Revisiting global trends in freshwater insect biodiversity." WIREs Water 8, no. 2: 1.
Since historical times, the inherent human fascination with pearls turned the freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) into a highly valuable cultural and economic resource. Although pearl harvesting in M. margaritifera is nowadays residual, other human threats have aggravated the species conservation status, especially in Europe. This mussel presents a myriad of rare biological features, e.g. high longevity coupled with low senescence and Doubly Uniparental Inheritance of mitochondrial DNA, for which the underlying molecular mechanisms are poorly known. Here, the first draft genome assembly of M. margaritifera was produced using a combination of Illumina Paired-end and Mate-pair approaches. The genome assembly was 2,4 Gb long, possessing 105,185 scaffolds and a scaffold N50 length of 288,726 bp. The ab initio gene prediction allowed the identification of 35,119 protein-coding genes. This genome represents an essential resource for studying this species’ unique biological and evolutionary features and ultimately will help to develop new tools to promote its conservation.
André Gomes-Dos-Santos; Manuel Lopes-Lima; André M. Machado; António Marcos Ramos; Ana Usié; Ivan N. Bolotov; Ilya V. Vikhrev; Sophie Breton; L. Filipe C. Castro; Rute R. da Fonseca; Juergen Geist; Martin E. Österling; Vincent Prié; Amílcar Teixeira; Han Ming Gan; Oleg Simakov; Elsa Froufe. The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758). 2020, 1 .
AMA StyleAndré Gomes-Dos-Santos, Manuel Lopes-Lima, André M. Machado, António Marcos Ramos, Ana Usié, Ivan N. Bolotov, Ilya V. Vikhrev, Sophie Breton, L. Filipe C. Castro, Rute R. da Fonseca, Juergen Geist, Martin E. Österling, Vincent Prié, Amílcar Teixeira, Han Ming Gan, Oleg Simakov, Elsa Froufe. The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758). . 2020; ():1.
Chicago/Turabian StyleAndré Gomes-Dos-Santos; Manuel Lopes-Lima; André M. Machado; António Marcos Ramos; Ana Usié; Ivan N. Bolotov; Ilya V. Vikhrev; Sophie Breton; L. Filipe C. Castro; Rute R. da Fonseca; Juergen Geist; Martin E. Österling; Vincent Prié; Amílcar Teixeira; Han Ming Gan; Oleg Simakov; Elsa Froufe. 2020. "The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758)." , no. : 1.
Oxygenated streambeds are considered a key requirement for the successful recruitment of stream fauna, including highly endangered freshwater pearl mussel Margaritifera margaritifera. Excessive amounts of fines impede exchange between open water and interstitial, leading to colmation and low oxygen levels in the juvenile habitat. Understanding the dynamic relationship between sediment delivery, transport, deposition and remobilization in relation to anthropogenic drivers is still poorly understood, yet is essential for conservation and restoration. This study analysed spatiotemporal sediment dynamics and interstitial habitat quality in five pearl mussel streams at the border region between Bavaria, Saxony and the Czech Republic during 2018 and 2019, comparing extremely dry periods with higher discharge events caused by snow melt and rainfall. Physicochemical habitat conditions within the streambed and sediment deposition were recorded in high spatial resolution along the stream courses, with a particular focus on the effects of tributaries and outflows of man-made fishponds. Habitat conditions were unsuitable for juvenile pearl mussels at the majority of sites, indicated by pronounced differences in physicochemical parameters between open water and the substrate, independent of discharge conditions. Sediment deposition varied markedly between discharge events, in terms of both the quality and quantity of deposits. Snow melt resulted in the highest sedimentation rates, but the smallest proportion of fine particles. During low flow conditions, fine sediment deposition was highly variable, ranging from 0.048 to 4.170 kg/week/m², mostly independent of flow velocity. High spatiotemporal variation was observed within and amongst stream systems, revealing different longitudinal patterns of fine sediment deposition, with catchment land use as the main driver. Temporal variability in sediment deposition was mainly associated with the discharge condition while abiotic parameters varied mainly with season. The high site-specificity of sedimentation rates and substrate conditions in response to different discharge events highlights the importance of an adapted conservation management which considers anthropogenic effects at the local scale.
Rebecca Hoess; Juergen Geist. Spatiotemporal variation of streambed quality and fine sediment deposition in five freshwater pearl mussel streams, in relation to extreme drought, strong rain and snow melt. Limnologica 2020, 85, 125833 .
AMA StyleRebecca Hoess, Juergen Geist. Spatiotemporal variation of streambed quality and fine sediment deposition in five freshwater pearl mussel streams, in relation to extreme drought, strong rain and snow melt. Limnologica. 2020; 85 ():125833.
Chicago/Turabian StyleRebecca Hoess; Juergen Geist. 2020. "Spatiotemporal variation of streambed quality and fine sediment deposition in five freshwater pearl mussel streams, in relation to extreme drought, strong rain and snow melt." Limnologica 85, no. : 125833.