TREICLAKE

Selle valdkonna püsiv URIhttp://hdl.handle.net/10492/7299

"Towards Research Excellence and Innovation Capacity in Studing Lake Ecosystems Functional Structures and Climate Change Impact " (1.01.2021−31.12.2023); Principal investigator: Lea Tuvikene, Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Chair of Hydrobiology and Fishery. Funder: European Commission

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Nüüd näidatakse 1 - 20 82

11th International Shallow Lakes Conference Estonia 11-16 June 2023 : [opening presentation]
(Estonian University of Life Sciences, 2023) Zingel, Priit
The presentation took place at the 11th International Shallow Lakes Conference.
6 põhjust, miks Peipsi järv vajab tähelepanu : [faktileht]
(Eesti Maaülikool, 2021) Eesti Maaülikool
Peipsi järv on Euroopa üks kalarikkam ja suurim piiriülene järv. Õigupoolest koosneb järv kolmest osast: Peipsi, Pihkva ja Lämmijärvest. Kuna jagame järve Venemaaga, siis keskkonnakaitse meetmeid tuleb ellu viia üheskoos. Peipsi-Pihkva järv on oma suuruse (3555 km2) kohta madal järv: tema keskmine sügavus on ainult 7,1 meetrit. Suurte ja madalate järvede ökoloogiline seisund ehk tervis oleneb väga palju keskkonnatngimustest. Järve tervist mõjutavad üheaegselt nii looduslikud kui inimtekkelised tegurid, seejuures on neil sageli raske vahet teha.
Amazon River – far and near : [posters]
(Estonian University of Life Sciences, 2022) Agasild, Helen (compiler); Zingel, Priit (compiler); Tuvikene, Arvo (compiler)
* Amazon river - far and near : opening poster of the exhibition. Projekti rahastab Horisont 2020, Euroopa Liidu teadusuuringute ja innovatsiooni raamprogramm grandiga nr. 951963, TREICLAKE. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963.
Amazonas – kaugel ja lähedal : [postrid]
(Eesti Maaülikool, 2022) Agasild, Helen (koostaja); Zingel, Priit (koostaja); Tuvikene, Arvo (koostaja)
* Amazonas - kaugel ja lähedal : näituse avaposter. Projekti rahastab Horisont 2020, Euroopa Liidu teadusuuringute ja innovatsiooni raamprogramm grandiga nr. 951963, TREICLAKE. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963.
Behavioural responses of invasive (Gmelinoides faciatus) and native (Gammarus lacustris) amphipods to predators on different bottom substrates : [poster]
(Estonian University of Life Sciences, 2023) Teesalu, Paul; Ercoli, Fabio; Tuvikene, Arvo
The amphipod Gmelinoides fasciatus has invaded and established in numerous large lakes in Eurasia and, in the process, has displaced the native amphipod, Gammarus lacustris. In Lake Peipsi, G. fasciatus dominates the shoreline macroinvertebrate fauna, forming up to 99% of macroinvertebrate individuals (Fig. 1). The mechanism behind its invasion success is unclear and remains an important topic for invasion ecology. In order to determine if different bottom substrates and predator avoidance behaviour contribute to the invasion success of G. fasciatus we conducted two laboratory experiments.
Behavioural responses of invasive (Gmelinoides fasciatus) and native (Gammarus lacustris) amphipods to predators on different bottom substrates
(Springer Nature, 2023) Teesalu, Paul; Ercoli, Fabio; Tuvikene, Arvo
The amphipod Gmelinoides fasciatus has invaded and established in numerous large lakes in Eurasia and, in the process, has displaced the native amphipod, Gammarus lacustris. The mechanism behind its invasion success is unclear and remains an important topic for invasion ecology. Three labo- ratory experiments were conducted to determine if superior predator avoidance and different types of bottom substrate could be important factors contrib- uting to the invasion success of G. fasciatus. Our results indicate that, on gravel and sand substrates, G. fasciatus exhibited superior digging behaviour to avoid predation by fishes (perch and common roach), contrary to G. lacustris. On sandy substrate, only 9% of G. fasciatus individuals were consumed, whereas G. lacustris were consumed much more intensively at 74%. In addition, G. fasciatus exhibited a more sub- stantial reduction in activity, where the time spent in motion reduced from 37.6 to 20.8% compared to G. lacustris (from 21.8 to 17.4%) when in the presence of predatory fish kairomones. G. fasciatus movement speed was also reduced in the presence of kairomones (from 57.1 to 39.3 mm/s). However, the presence of kairomones had little effect on digging behaviour of G. fasciatus. G. fasciatus consistently demonstrated superior predator avoidance abilities over G. lacus- tris, suggesting that this mechanism might play an important role in the invasion success of G. fasciatus.
Bimodality and alternative equilibria do not help explain long-term patterns in shallow lake chlorophyll-a
(Springer Nature, 2023) Davidson, Thomas A.; Sayer, Carl D.; Jeppesen, Erik; Søndergaard, Martin; Lauridsen, Torben; Johansson, Liselotte S.; Baker, Ambroise; Graeber, Daniel
Since its inception, the theory of alternative equilibria in shallow lakes has evolved and been applied to an ever wider range of ecological and socioecological systems. The theory posits the existence of two alternative stable states or equilibria, which in shallow lakes are characterised by either clear water with abundant plants or turbid water where phytoplankton dominate. Here, we used data simulations and real-world data sets from Denmark and north-eastern USA (902 lakes in total) to examine the relationship between shallow lake phytoplankton biomass (chlorophyll-a) and nutrient concentrations across a range of timescales. The data simulations demonstrated that three diagnostic tests could reliably identify the presence or absence of alternative equilibria. The real-world data accorded with data simulations where alternative equilibria were absent. Crucially, it was only as the temporal scale of observation increased (>3 years) that a predictable linear relationship between nutrient concentration and chlorophyll-a was evident. Thus, when a longer term perspective is taken, the notion of alternative equilibria is not required to explain the response of chlorophyll-a to nutrient enrichment which questions the utility of the theory for explaining shallow lake response to, and recovery from, eutrophication.
Black and white, day and night – fish diurnal movements in two different Amazonian lakes : [presentation]
(2021) Zingel, Priit; Tuvikene, Arvo; Feldmann, Tõnu; Agasild, Helen
The presentation took place at the 10th International Conference on Shallow Lakes in 2021.
Catchment land cover and soil as predictors of organic carbon, nitrogen, and phosphorus levels in temperate lakes : [presentation]
(Estonian University of Life Sciences, 2021) Sepp, Margot; Kõiv, Toomas; Nõges, Peeter; Nõges, Tiina; Newell, Silvia; McCarthy, Mark J.
The presentation took place at the 10th International Conference on Shallow Lakes in 2021.
Catchment soil characteristics predict organic carbon, nitrogen, and phosphorus levels in temperate lakes
(The University of Chicago Press, 2021) Sepp, Margot; Kõiv, Toomas; Nõges, Peeter; Nõges, Tiina; Newell, Silvia E.; McCarthy, Mark J.; Institute of Agricultural and Environmental Sciences. Estonian University of Life Sciences
Allochthonous supply of dissolved organic matter (DOM) and nutrients from the catchment have a sub- stantial impact on the physical and chemical properties of lake water. Transport of DOM and nutrients is affected by different catchment characteristics, e.g., catchment area, soil and land cover, and population density. The aim of this study was to relate geological, hydrological, land-cover, and soil characteristics of 52 temperate catchments in Estonia to variability in DOM (measured as dissolved organic carbon [DOC]), total organic nitrogen (TON), and total phosphorus (TP) in lakes and to assess the relative importance of different land-cover and soil types as sources of these substances. DOC, TON, and TP were very diverse in the studied lakes. Strong positive correlation between DOC and TON indicated that these substances had similar concentration patterns and sources. Catchment soil cover was the best predictor of DOC, TON, and TP levels in lakes, explaining up to 43.8% of their variabilities. This obser- vation can partly be explained by different soil organic carbon (SOC) content: soils with higher SOC were associated with higher lake DOC and TON, whereas soils with low SOC corresponded to lower DOC and TON. Similar to other temperate lakes, bogs and peat soils were a major source of DOM in our studied lakes. DOC, TON, and color were positively associated with percentages of peat soils in the catchment. On the other hand, TP increased with the pro- portion of urban areas in the catchments, indicating the importance of human impact on its concentration. Under- standing the impact of different catchment characteristics on DOC, TON, and TP in temperate lakes is crucial for developing transport models used for predicting future levels of DOM and nutrients under changing climate and land use.
Causal networks of phytoplankton diversity and biomass are modulated by environmental context
(Nature Research, 2022) Chang, Chun-Wei; Miki, Takeshi; Ye, Hao; Souissi, Sami; Adrian, Rita; Anneville, Orlane; Agasild, Helen; Ban, Syuhei; Be’eri-Shlevin, Yaron; Chiang, Yin-Ru; Feuchtmayr, Heidrun; Gal, Gideon; Ichise, Satoshi; Kagami, Maiko; Kumagai, Michio; Liu, Xin; Matsuzaki, Shin-Ichiro S.; Manca, Marina M.; Nõges, Peeter; Piscia, Roberta; Rogora, Michela; Shiah, Fuh-Kwo; Thackeray, Stephen J.; Widdicombe, Claire E.; Wu, Jiunn-Tzong; Zohary, Tamar; Hsieh, Chih-hao
Untangling causal links and feedbacks among biodiversity, ecosystem functioning, and environmental factors is challenging due to their complex and context-dependent interactions (e.g., a nutrient-dependent relationship between diversity and biomass). Consequently, studies that only consider separable, unidirectional effects can produce divergent conclusions and equivocal ecological implications. To address this complexity, we use empirical dynamic modeling to assemble causal networks for 19 natural aquatic ecosystems (N24°~N58°) and quantified strengths of feedbacks among phytoplankton diversity, phytoplankton biomass, and environmental factors. Through a cross-system comparison, we identify macroecological patterns; in more diverse, oligotrophic ecosystems, biodiversity effects are more important than environmental effects (nutrients and temperature) as drivers of biomass. Furthermore, feedback strengths vary with productivity. In warm, productive systems, strong nitratemediated feedbacks usually prevail, whereas there are strong, phosphate-mediated feedbacks in cold, less productive systems. Our findings, based on recovered feedbacks, highlight the importance of a network view in future ecosystem management.
The Challenge of Understanding – from Protozoa to Ecosystems : [presentation]
(Estonian University of Life Sciences, 2023) Zingel, Priit
The presentation took place at the 23rd biennial conference EcoBalt2023.
Changes in nutrient concentration and water level affect the microbial loop: a 6‑month mesocosm experiment
(Springer, 2023) Zingel, Priit; Jeppesen, Erik; Nõges, Tiina; Hejzlar, Josef; Tavşanoğlu, Ülkü Nihan; Papastergiadou, Eva; Scharfenberger, Ulrike; Agasild, Helen
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 in fully mixed shallow lakes, we manipulated water depth and nutrients in a lake mesocosm experiment in north temperate Estonia and followed the microbial community dynamics over a 6-month period. The experiment was carried out in Lake Võrtsjärv—a large, shallow eutrophic lake. 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 the biomasses of bacterial and heterotrophic nanoflagellates (HNF) (RM-ANOVA, p < 0.05). Nutrients affected positively and depth negatively the mean size of individual HNF and ciliate cells (RM-ANOVA; p < 0.05). The interactions of depth and nutrients affected positively the biomass of bacterivorous and bacteriherbivorous ciliates and negatively the biomass of predaceous ciliates (RM-ANOVA; p < 0.05). 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.
Changes in nutrient concentration and water level affect the microbial loop: a multi-seasonal mesocosm experiment : [submitted version]
(Springer, 2023) Zingel, Priit; Jeppesen, Erik; Nõges, Tiina; Hejzlar, Josef; Tavşanoğlu, Ülkü Nihan; Papastergiadou, Eva; Scharfenberger, Ulrike; Agasild, Helen; Centre for Limnology
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.
Climate change affects lakes. What can we do?: Policy brief, June 26, 2023
(Estonian University of Life Sciences, 2023) Tuvikene, Lea; Nõges, Peeter
✓ Lake ecosystems provide vital services for humanity, but, due to global climate change, the quality and quantity of these services is decreasing. ✓ Lakes supply us with clean water and fish, they regulate nutrient cycling and modify climate change effects by controlling floods and the amount of CO2, which is the main cause of climate warming. In an urbanizing world, the aesthetic and recreational importance of lakes for human well-being is increasing. ✓ Changes in temperature, precipitation and wind affect lake levels and water availability, alter the distribution of oxygen and nutrients, and impact the survival and abundance of aquatic organisms: algal blooms expand causing massive fish kills. ✓ Understanding these mutual interactions through improved climate models, monitoring of water quality, and assessing ecosystem health is crucial for managing and mitigating the impacts of climate change on lakes. ✓ As the impact of eutrophication and climate change follow the same pathways affecting nutrient availability and cascading effects in the food web, establishing stricter control over anthropogenic nutrient loading is the most efficient adaptive strategy to preserve the ecological integrity of lakes and the services they provide.
Climate change impact on Estonian lakes : [presentation]
(Estonian University of Life Sciences, 2023) Laas, Alo; Cremona, Fabien; Maljutenko, Ilja; Raudsepp, Urmas; Uiboupin, Rivo; Ott, Ingmar
The presentation took place at the 11th International Shallow Lakes Conference.
Combining different omics to study aquatic food web functions and processes : [presentation]
(University of Jyväskylä, 2023) Taipale, Sami J.
The presentation took place at the 11th International Shallow Lakes Conference.
Comparison of larval perch feeding between littoral and open-water sites of the lakes : [presentation]
(Estonian University of Life Sciences, 2021) Karus, Katrit; Žagars, Matiss; Zingel, Priit; Agasild, Helen; Feldmann, Tõnu; Tuvikene, Arvo; Medne-Peipere, Madara; Puncule, Linda
The presentation took place at the 10th International Conference on Shallow Lakes in 2021.
The comparison of the feeding of European perch Perca fluviatilis L. larvae in littoral and pelagic habitats of northern temperate lakes
(Estonian Academy Publishers, 2022) Karus, Katrit; Zagars, Matiss; Agasild, Helen; Feldmann, Tõnu; Tuvikene, Arvo; Puncule, Linda; Zingel, Priit; Chair of Hydrobiology and Fishery; Centre for Limnology
We studied the feeding of European perch Perca fluviatilis L. larvae in littoral and pelagic habitats of four different lakes – one Latvian (Auciema) and three Estonian (Akste, Kaiavere, and Prossa). Altogether, 162 perch larvae (81 from both habitats) were collected to estimate the diet composition of gathered larval specimens in spring (2019) using gut content analysis via epifluorescence microscopy. Attention was paid particularly to the question how does the larval perch food composition differ in pelagic and littoral habitats. We hypothesized that the consumption of zooplankton is higher and the larval condition is better in littoral habitats. We assessed the feeding on both protozoo- (ciliates) and metazooplankton and applied multiple indices (Hurlbert’s standardized niche breadth, Ivlev’s selectivity and relative importance index) to evaluate, respectively, the larval fish prey importance, feeding homogeneity and strategies. The results showed that larval length and weight were slightly higher and body condition was slightly better in the lakes’ littoral habitats. The feeding niche of perch larvae was narrower in the littoral, which can indicate more favourable feeding conditions in littoral than lake pelagic habitats. While the small cladocerans (Bosmina longirostris Müller) were generally the preferred and important food objects, ciliates were avoided and consumed only when their share in the total zooplankton biomass was >40%. However, in shortage of cladocerans, ciliates could be vitally important food objects for perch larvae.
Cross border cooperation on environmental monitoring of Lake Peipsi: main results and perspectives : [presentation]
(Estonian University of Life Sciences, 2021) Tuvikene, Lea; Tammeorg, Olga; Nõges, Peeter; Nõges, Tiina
The presentation took place at the Lahti Lakes 2021 Symposium.

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