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8. Two-Decade Changes in the Ciliate Assemblage Feeding Pattern Reflect the Reservoir Nutrient Load.

Author

Macek, Miroslav, Vrba, Jaroslav, Hejzlar, Josef, Řeháková, Klára, Jarošík, Jiří, Šorf, Michal, and Šimek, Karel

Subjects
AUTUMN, CRYPTOMONADS, BIOMASS, MULTIVARIATE analysis, PLANKTON, CILIATA
Abstract

The perception of the importance of ciliate in freshwater has changed dramatically since the "microbial loop" conceptualisation, reflecting methodological attempts. The data from two decades (1994–2018) on the surface (0–3 m) ciliate assemblage in the Slapy reservoir (Vltava River, Czech Republic) during two different nutrient-load defined periods were analysed. We grouped the identified, quantified, and biomass-evaluated ciliates in the quantitative protargol-impregnated preparations according to their feeding behaviour. The sampling median and interquartile range data of the ciliates were plotted; the modelled water age, nutrients, bacteria, heterotrophic nanoflagellates, and Rhodomonas spp. were applied as the main explanatory background variables. We validated the differences between the periods, engaging multivariate analyses. The picoplankton-filtering species dominated the assemblages in an annual mean (halteriids and minute strobilidiids followed by peritrichs). Algae hunting urotrichs, Balanion planctonicum, and nanoplankton filtering tintinnids were significant before the spring phytoplankton peak when a maximum of ciliate biomass reflected mixotrophic nanoplankton filtering pelagostrombidiids. Only there did ciliate biomass tightly follow their quantified prey. Heterotrophic and mixotrophic Askenasia and Lagynophrya were typical raptorial/flagellate-hunting cilates; only Mesodinium spp. reached the maximum during autumn. The observed oligotrophication of the reservoir increased the ciliate assemblage biomass in the surface layer during stratification in concordance with the Plankton Ecology Group (PEG) model. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming

Author

Weyhenmeyer, Gesa A, Mackay, Murray, Stockwell, Jason D, Thiery, Wim, Grossart, Hans-Peter, Augusto-Silva, Pétala B, Baulch, Helen M, de Eyto, Elvira, Hejzlar, Josef, Kangur, Külli, Kirillin, Georgiy, Pierson, Don C, Rusak, James A, Sadro, Steven, and Woolway, R Iestyn

Subjects
Earth Sciences, Atmospheric Sciences, Climate Action
Abstract

Citizen science projects have a long history in ecological studies. The research usefulness of such projects is dependent on applying simple and standardized methods. Here, we conducted a citizen science project that involved more than 3500 Swedish high school students to examine the temperature difference between surface water and the overlying air (Tw-Ta) as a proxy for sensible heat flux (QH). If QH is directed upward, corresponding to positive Tw-Ta, it can enhance CO2 and CH4 emissions from inland waters, thereby contributing to increased greenhouse gas concentrations in the atmosphere. The students found mostly negative Tw-Ta across small ponds, lakes, streams/rivers and the sea shore (i.e. downward QH), with Tw-Ta becoming increasingly negative with increasing Ta. Further examination of Tw-Ta using high-frequency temperature data from inland waters across the globe confirmed that Tw-Ta is linearly related to Ta. Using the longest available high-frequency temperature time series from Lake Erken, Sweden, we found a rapid increase in the occasions of negative Tw-Ta with increasing annual mean Ta since 1989. From these results, we can expect that ongoing and projected global warming will result in increasingly negative Tw-Ta, thereby reducing CO2 and CH4 transfer velocities from inland waters into the atmosphere.

Published
2017

12. Widespread deoxygenation of temperate lakes

Author

Jane, Stephen F., Hansen, Gretchen J. A., Kraemer, Benjamin M., Leavitt, Peter R., Mincer, Joshua L., North, Rebecca L., Pilla, Rachel M., Stetler, Jonathan T., Williamson, Craig E., Woolway, R. Iestyn, Arvola, Lauri, Chandra, Sudeep, DeGasperi, Curtis L., Diemer, Laura, Dunalska, Julita, Erina, Oxana, Flaim, Giovanna, Grossart, Hans-Peter, Hambright, K. David, Hein, Catherine, Hejzlar, Josef, Janus, Lorraine L., Jenny, Jean-Philippe, Jones, John R., Knoll, Lesley B., Leoni, Barbara, Mackay, Eleanor, Matsuzaki, Shin-Ichiro S., McBride, Chris, Müller-Navarra, Dörthe C., Paterson, Andrew M., Pierson, Don, Rogora, Michela, Rusak, James A., Sadro, Steven, Saulnier-Talbot, Emilie, Schmid, Martin, Sommaruga, Ruben, Thiery, Wim, Verburg, Piet, Weathers, Kathleen C., Weyhenmeyer, Gesa A., Yokota, Kiyoko, and Rose, Kevin C.

Published
2021
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13. Global Lake Health in the Anthropocene : Societal Implications and Treatment Strategies

Author

Weyhenmeyer, Gesa A., Chukwuka, Azubuike V., Anneville, Orlane, Brookes, Justin, Carvalho, Carolinne R., Cotner, James B., Grossart, Hans-Peter, Hamilton, David P., Hanson, Paul C., Hejzlar, Josef, Hilt, Sabine, Hipsey, Matthew R., Ibelings, Bas W., Jacquet, Stephan, Kangur, Kuelli, Kragh, Theis, Lehner, Bernhard, Lepori, Fabio, Lukubye, Ben, Marce, Rafael, Mcelarney, Yvonne, Paule-Mercado, Ma. Cristina, North, Rebecca, Rojas-Jimenez, Keilor, Rusak, James A., Sharma, Sapna, Scordo, Facundo, de Senerpont Domis, Lisette N., So, Jonas Stage, Wood, Susanna (Susie) A., Xenopoulos, Marguerite A., Zhou, Yongqiang, Weyhenmeyer, Gesa A., Chukwuka, Azubuike V., Anneville, Orlane, Brookes, Justin, Carvalho, Carolinne R., Cotner, James B., Grossart, Hans-Peter, Hamilton, David P., Hanson, Paul C., Hejzlar, Josef, Hilt, Sabine, Hipsey, Matthew R., Ibelings, Bas W., Jacquet, Stephan, Kangur, Kuelli, Kragh, Theis, Lehner, Bernhard, Lepori, Fabio, Lukubye, Ben, Marce, Rafael, Mcelarney, Yvonne, Paule-Mercado, Ma. Cristina, North, Rebecca, Rojas-Jimenez, Keilor, Rusak, James A., Sharma, Sapna, Scordo, Facundo, de Senerpont Domis, Lisette N., So, Jonas Stage, Wood, Susanna (Susie) A., Xenopoulos, Marguerite A., and Zhou, Yongqiang

Abstract

The world's 1.4 million lakes (>= 10 ha) provide many ecosystem services that are essential for human well-being; however, only if their health status is good. Here, we reviewed common lake health issues and classified them using a simple human health-based approach to outline that lakes are living systems that are in need of oxygen, clean water and a balanced energy and nutrient supply. The main reason for adopting some of the human health terminology for the lake health classification is to increase the awareness and understanding of global lake health issues. We show that lakes are exposed to various anthropogenic stressors which can result in many lake health issues, ranging from thermal, circulatory, respiratory, nutritional and metabolic issues to infections and poisoning. Of particular concern for human well-being is the widespread lake drying, which is a severe circulatory issue with many cascading effects on lake health. We estimated that similar to 115,000 lakes evaporate twice as much water as they gain from direct precipitation, making them vulnerable to potential drying if inflowing waters follow the drying trend, putting more than 153 million people at risk who live in close vicinity to those lakes. Where lake health issues remain untreated, essential ecosystem services will decline or even vanish, posing a threat to the well-being of millions of people. We recommend coordinated multisectoral and multidisciplinary prevention and treatment strategies, which need to include a follow-up of the progress and an assessment of the resilience of lakes to intensifying threats. Priority should be given to implementing sewage water treatment, mitigating climate change, counteracting introductions of non-native species to lakes and decreasing uncontrolled anthropogenic releases of chemicals into the hydro-, bio-, and atmosphere. Lakes around the world come in an array of sizes, shapes and colors, each telling a unique story of geological history and environment

Published
2024
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16. Unveiling the Role of Biological and Environmental Factors and the Piscivory in the Recruitment Success of Pikeperch (Stizostedion Lucioperca)

Author

Tesfaye, Million, primary, Juza, Tomas, additional, Šmejkal, Marek, additional, Soukalová, Katerina, additional, Bartoň, Daniel, additional, Blabolil, Petr, additional, Čech, Martin, additional, Hejzlar, Josef, additional, Prchalová, Marie, additional, Muška, Milan, additional, Tušer, Michal, additional, Kočvara, Luboš, additional, Sajdlová, Zuzana, additional, Draštík, Vladislav, additional, Martinez, Carlos, additional, de Moraes, Karlos Ribeiro, additional, Říha, Milan, additional, Vašek, Mojmír, additional, Symonová, Radka, additional, Brabec, Marek, additional, Kubečka, Jan, additional, and Souza, Allan T., additional

Published
2024
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28. Distribution patterns, annual density changes, growth and mortality of pikeperch [Sander lucioperca (L. 1758)] fry following oligotrophication of a reservoir

Author

Jůza, Tomáš, primary, Blabolil, Petr, additional, Čech, Martin, additional, Draštík, Vladislav, additional, Hejzlar, Josef, additional, Kočvara, Luboš, additional, Muška, Milan, additional, Peterka, Jiří, additional, Sajdlová, Zuzana, additional, Tušer, Michal, additional, Vašek, Mojmír, additional, and Kubečka, Jan, additional

Published
2023
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29. Fish scale stable isotopes as potential indicators of nutrient pollution: Exploring the response of roach (Rutilus rutilus) scale δ15N and δ13C to a gradient of land use disturbance

Author

Vašek, Mojmír, primary, Brabec, Marek, additional, Blabolil, Petr, additional, Čech, Martin, additional, Draštík, Vladislav, additional, Jůza, Tomáš, additional, Kubečka, Jan, additional, Muška, Milan, additional, Peterka, Jiří, additional, Prchalová, Marie, additional, Říha, Milan, additional, and Hejzlar, Josef, additional

Published
2023
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32. Widespread diminishing anthropogenic effects on calcium in freshwaters

Author

Weyhenmeyer, Gesa A., Hartmann, Jens, Hessen, Dag O., Kopáček, Jiří, Hejzlar, Josef, Jacquet, Stéphan, Hamilton, Stephen K., Verburg, Piet, Leach, Taylor H., Schmid, Martin, Flaim, Giovanna, Nõges, Tiina, Nõges, Peeter, Wentzky, Valerie C., Rogora, Michela, Rusak, James A., Kosten, Sarian, Paterson, Andrew M., Teubner, Katrin, Higgins, Scott N., Lawrence, Gregory, Kangur, Külli, Kokorite, Ilga, Cerasino, Leonardo, Funk, Clara, Harvey, Rebecca, Moatar, Florentina, de Wit, Heleen A., and Zechmeister, Thomas

Published
2019
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35. Changes in nutrient concentration and water level affect the microbial loop: a multi-seasonal mesocosm experiment

Author

Zingel, Priit, Jeppesen, Erik, Nõges, Tiina, Hejzlar, Josef, Tavşanoğlu, Ülkü Nihan, Papastergiadou, Eva, Scharfenberger, Ulrike, Agasild, Helen, and Centre for Limnology

Subjects
protozoa, eutrophication, heterotrophic nanoflagellates, articles, top-down and bottom-up control, bacteria
Abstract

Eutrophication and lake depth are of key importance in structuring lake ecosystems. To elucidate the effect of contrasting nutrient concentrations and water levels on the microbial community, we manipulated water depth and nutrients in a mesocosm experiment in north temperate Estonia and followed the microbial community dynamics during a 6-month period. We used two nutrient levels crossed with two water depths, each represented by four replicates. We found treatment effects on the microbial food web structure, with nutrients having a positive and water depth a negative effect on bacterial biomass, heterotrophic nanoflagellates (HNF) and metazooplankton biomass. Nutrients and water depth had both positive impacts on phytoplankton biomass. Bacterivorous ciliates had lowest biomass in shallow and nutrient rich mesocosms, whilst predaceous ciliates had highest biomass here, influencing trophic interactions in the microbial loop. Overall, increased nutrient concentrations and decreased water level resulted in an enhanced bacterial biomass and a decrease in their main grazers. These differences appeared to reflect distinctive regulation mechanisms inside the protozoan community and in the trophic interactions in the microbial loop community. This work was supported by EU 7FP Theme 6 projects MARS (Managing Aquatic ecosystems and water Resources under multiple Stress, Contract No. 603378), Estonian Ministry of Education and Research (IUT 21-02), Estonian Research Council grant PRG709, Estonian University of Life Sciences (P190258PKKH) and Swiss Grant for Programme "Enhancing public environmental monitoring capacities". This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963. Erik Jeppesen was also supported by the TÜBITAK program BIDEB2232 (project 118C250). This work was supported by EU 7FP Theme 6 projects MARS (Managing Aquatic ecosystems and water Resources under multiple Stress, Contract No. 603378), Estonian Ministry of Education and Research (IUT 21-02), Estonian Research Council grant PRG709, Estonian University of Life Sciences (P190258PKKH) and Swiss Grant for Programme "Enhancing public environmental monitoring capacities". This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963. Erik Jeppesen was also supported by the TÜBITAK program BIDEB2232 (project 118C250).

Published
2023

36. Effects of nutrient and water level changes on the composition and size structure of zooplankton communities in shallow lakes under different climatic conditions: a pan-European mesocosm experiment

Author

Tavşanoğlu, Ülkü Nihan, Šorf, Michal, Stefanidis, Konstantinos, Brucet, Sandra, Türkan, Semra, Agasild, Helen, Baho, Didier L., Scharfenberger, Ulrike, Hejzlar, Josef, Papastergiadou, Eva, Adrian, Rita, Angeler, David G., Zingel, Priit, Çakıroğlu, Ayşe İdil, Özen, Arda, Drakare, Stina, Søndergaard, Martin, Jeppesen, Erik, and Beklioğlu, Meryem

Published
2017
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40. Carbon metabolism and nutrient balance in a hypereutrophic semi-intensive fishpond

Author

Rutegwa Marcellin, Potužák Jan, Hejzlar Josef, and Drozd Bořek

Subjects
aquaculture pond, input use efficiency, metabolism, organic carbon, nitrogen, phosphorus, primary production, freshwater fish production, Aquaculture. Fisheries. Angling, SH1-691
Abstract

Eutrophication and nutrient pollution is a serious problem in many fish aquaculture ponds, whose causes are often not well documented. The efficiency of using inputs for fish production in a hypereutrophic fishpond (Dehtář), was evaluated using organic carbon (OC), nitrogen (N) and phosphorus (P) balances and measurement of ecosystem metabolism rates in 2015. Primary production and feeds were the main inputs of OC and contributed 82% and 13% to the total OC input, respectively. Feeds and manure were the major inputs of nutrients and contributed 73% and 86% of the total inputs of N and P, respectively. Ecosystem respiration, accumulation in water and accumulation in sediment were the main fates of OC, N and P, respectively. They accounted for 79%, 52% and 61% of OC, N and P inputs. The efficiency of using OC, N and P inputs to produce fish biomass was very low and represented 0.9%, 25% and 23% of total OC, N, and P inputs, indicating an excessive phytoplankton production and overdosing of fish feeds and manure. Dehtář pond was slightly autotrophic and phosphorus availability did not limit the phytoplankton growth. The low efficiency of using inputs was attributed to the low digestibility of raw cereals grain used as feed and the inability of planktonic food webs to transfer the primary production to fish due to high predatory pressure of fish stock on zooplankton. The primary production is an important input of OC in semi-intensive fishponds and should be considered in evaluations of fish production efficiency.

Published
2019
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42. A framework for ensemble modelling of climate change impacts on lakes worldwide: the ISIMIP Lake Sector

Author

Golub, Malgorzata, primary, Thiery, Wim, additional, Marcé, Rafael, additional, Pierson, Don, additional, Vanderkelen, Inne, additional, Mercado-Bettin, Daniel, additional, Woolway, R. Iestyn, additional, Grant, Luke, additional, Jennings, Eleanor, additional, Kraemer, Benjamin M., additional, Schewe, Jacob, additional, Zhao, Fang, additional, Frieler, Katja, additional, Mengel, Matthias, additional, Bogomolov, Vasiliy Y., additional, Bouffard, Damien, additional, Côté, Marianne, additional, Couture, Raoul-Marie, additional, Debolskiy, Andrey V., additional, Droppers, Bram, additional, Gal, Gideon, additional, Guo, Mingyang, additional, Janssen, Annette B. G., additional, Kirillin, Georgiy, additional, Ladwig, Robert, additional, Magee, Madeline, additional, Moore, Tadhg, additional, Perroud, Marjorie, additional, Piccolroaz, Sebastiano, additional, Raaman Vinnaa, Love, additional, Schmid, Martin, additional, Shatwell, Tom, additional, Stepanenko, Victor M., additional, Tan, Zeli, additional, Woodward, Bronwyn, additional, Yao, Huaxia, additional, Adrian, Rita, additional, Allan, Mathew, additional, Anneville, Orlane, additional, Arvola, Lauri, additional, Atkins, Karen, additional, Boegman, Leon, additional, Carey, Cayelan, additional, Christianson, Kyle, additional, de Eyto, Elvira, additional, DeGasperi, Curtis, additional, Grechushnikova, Maria, additional, Hejzlar, Josef, additional, Joehnk, Klaus, additional, Jones, Ian D., additional, Laas, Alo, additional, Mackay, Eleanor B., additional, Mammarella, Ivan, additional, Markensten, Hampus, additional, McBride, Chris, additional, Özkundakci, Deniz, additional, Potes, Miguel, additional, Rinke, Karsten, additional, Robertson, Dale, additional, Rusak, James A., additional, Salgado, Rui, additional, van der Linden​​​​​​​, Leon, additional, Verburg, Piet, additional, Wain, Danielle, additional, Ward, Nicole K., additional, Wollrab, Sabine, additional, and Zdorovennova, Galina, additional

Published
2022
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46. A framework for ensemble modelling of climate change impacts on lakes worldwide: the ISIMIP Lake Sector

Author

Golub, Malgorzata, Thiery, Wim, Marcé, Rafael, Pierson, Don, Vanderkelen, Inne, Mercado-Bettin, Daniel, Woolway, R. Iestyn, Grant, Luke, Jennings, Eleanor, Kraemer, Benjamin M., Schewe, Jacob, Zhao, Fang, Frieler, Katja, Mengel, Matthias, Bogomolov, Vasiliy Y., Bouffard, Damien, Côté, Marianne, Couture, Raoul-Marie, Debolskiy, Andrey V., Droppers, Bram, Gal, Gideon, Guo, Mingyang, Janssen, Annette B.G., Kirillin, Georgiy, Ladwig, Robert, Magee, Madeline, Moore, Tadhg, Perroud, Marjorie, Piccolroaz, Sebastiano, Raaman Vinnaa, Love, Schmid, Martin, Shatwell, Tom, Stepanenko, Victor M., Tan, Zeli, Woodward, Bronwyn, Yao, Huaxia, Adrian, Rita, Allan, Mathew, Anneville, Orlane, Arvola, Lauri, Atkins, Karen, Boegman, Leon, Carey, Cayelan, Christianson, Kyle, de Eyto, Elvira, DeGasperi, Curtis, Grechushnikova, Maria, Hejzlar, Josef, Joehnk, Klaus, Jones, Ian D., Laas, Alo, Mackay, Eleanor B., Mammarella, Ivan, Markensten, Hampus, McBride, Chris, Özkundakci, Deniz, Potes, Miguel, Rinke, Karsten, Robertson, Dale, Rusak, James A., Salgado, Rui, van der Linden​​​​​​​, Leon, Verburg, Piet, Wain, Danielle, Ward, Nicole K., Wollrab, Sabine, Zdorovennova, Galina, Golub, Malgorzata, Thiery, Wim, Marcé, Rafael, Pierson, Don, Vanderkelen, Inne, Mercado-Bettin, Daniel, Woolway, R. Iestyn, Grant, Luke, Jennings, Eleanor, Kraemer, Benjamin M., Schewe, Jacob, Zhao, Fang, Frieler, Katja, Mengel, Matthias, Bogomolov, Vasiliy Y., Bouffard, Damien, Côté, Marianne, Couture, Raoul-Marie, Debolskiy, Andrey V., Droppers, Bram, Gal, Gideon, Guo, Mingyang, Janssen, Annette B.G., Kirillin, Georgiy, Ladwig, Robert, Magee, Madeline, Moore, Tadhg, Perroud, Marjorie, Piccolroaz, Sebastiano, Raaman Vinnaa, Love, Schmid, Martin, Shatwell, Tom, Stepanenko, Victor M., Tan, Zeli, Woodward, Bronwyn, Yao, Huaxia, Adrian, Rita, Allan, Mathew, Anneville, Orlane, Arvola, Lauri, Atkins, Karen, Boegman, Leon, Carey, Cayelan, Christianson, Kyle, de Eyto, Elvira, DeGasperi, Curtis, Grechushnikova, Maria, Hejzlar, Josef, Joehnk, Klaus, Jones, Ian D., Laas, Alo, Mackay, Eleanor B., Mammarella, Ivan, Markensten, Hampus, McBride, Chris, Özkundakci, Deniz, Potes, Miguel, Rinke, Karsten, Robertson, Dale, Rusak, James A., Salgado, Rui, van der Linden​​​​​​​, Leon, Verburg, Piet, Wain, Danielle, Ward, Nicole K., Wollrab, Sabine, and Zdorovennova, Galina

Abstract

Empirical evidence demonstrates that lakes and reservoirs are warming across the globe. Consequently, there is an increased need to project future changes in lake thermal structure and resulting changes in lake biogeochemistry in order to plan for the likely impacts. Previous studies of the impacts of climate change on lakes have often relied on a single model forced with limited scenario-driven projections of future climate for a relatively small number of lakes. As a result, our understanding of the effects of climate change on lakes is fragmentary, based on scattered studies using different data sources and modelling protocols, and mainly focused on individual lakes or lake regions. This has precluded identification of the main impacts of climate change on lakes at global and regional scales and has likely contributed to the lack of lake water quality considerations in policy-relevant documents, such as the Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC). Here, we describe a simulation protocol developed by the Lake Sector of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) for simulating climate change impacts on lakes using an ensemble of lake models and climate change scenarios for ISIMIP phases 2 and 3. The protocol prescribes lake simulations driven by climate forcing from gridded observations and different Earth system models under various representative greenhouse gas concentration pathways (RCPs), all consistently bias-corrected on a 0.5∘ × 0.5∘ global grid. In ISIMIP phase 2, 11 lake models were forced with these data to project the thermal structure of 62 well-studied lakes where data were available for calibration under historical conditions, and using uncalibrated models for 17 500 lakes defined for all global grid cells containing lakes. In ISIMIP phase 3, this approach was expanded to consider more lakes, more models, and more processes. The ISIMIP Lake Sector is the largest international effort to project

Published
2022

49. Land Use Change to Reduce Freshwater Nitrogen and Phosphorus will Be Effective Even with Projected Climate Change

Author

Wade, Andrew J., primary, Skeffington, Richard A., additional, Couture, Raoul-Marie, additional, Erlandsson Lampa, Martin, additional, Groot, Simon, additional, Halliday, Sarah J., additional, Harezlak, Valesca, additional, Hejzlar, Josef, additional, Jackson-Blake, Leah A., additional, Lepistö, Ahti, additional, Papastergiadou, Eva, additional, Riera, Joan Lluís, additional, Rankinen, Katri, additional, Shahgedanova, Maria, additional, Trolle, Dennis, additional, Whitehead, Paul G., additional, Psaltopoulos, Demetris, additional, and Skuras, Dimitris, additional

Published
2022
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