Effect of water chemistry on zooplanktonic and microbial communities across freshwater ecotones in different macrophyte-dominated shallow lakes

Complex interactions between zooplankton and microbial food webs are vital to the ecosystem ecology of shallow lakes. However, little is known about how horizontal changes in environmental conditions may influence microbial and metazoan communities in shallow lakes. The specific goals of the study were i) to describe environmental variables responsible for the distribution of bacteria, flagellates, ciliates and crustaceans in an adjacent canal, ecotone and reservoir (littoral-pelagic zone) in two different types of lakes (Ceratophyllum-dominated and Potamogeton-dominated lakes); ii) to determine whether the contact zone waters differ in hydrochemical and biological terms from the waters of the canal and the open water zone; iii) and to evaluate the influence of particular macro-habitats (canal, canal/reservoir, littoral and pelagic zone) on the interactions between components of the planktonic food web. We studied four shallow, eutrophic lakes in Polesie Lubelskie (eastern Poland). The highest diversity and abundance of microorganisms and crustaceans were observed in the canal-reservoir contact zone, while the lowest values were noted in the pelagic zone. Hence, the contact zone in the investigated lakes could fulfil the function of an ecotone, distinguished by a significant increase in biodiversity, abundance, and species specificity of micro- and macroorganisms. Weak relations between food web components were found in the Ceratophyllum-dominated lakes, where environmental variables explained the bulk of the total variance in plankton abundance, whereas in the Potamogeton-dominated lakes, where environmental variables had a minor role in the total variance in plankton abundance, strong predator-prey relations were noted. Spatial structure of habitats proved to be another important factor for relationships between food web components, as our study indicated that habitat complexity can reduce negative correlations between food web components. Our study contributes to knowledge of the functioning of eutrophic lakes in the current era of increasing eutrophication caused by climate change and human activity.

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The effect of epiphytic macroinvertebrates on microbial communities in different types of macrophyte-dominated shallow lakes

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2017060 ◽

2018 ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Tomasz Mieczan ◽

Monika Tarkowska-Kukuryk ◽

Diana Ȃrva ◽

Làszló Berzni-Nagy ◽

Zoltan Novak ◽

...

Keyword(s):

Food Web ◽

Microbial Communities ◽

Shallow Lakes ◽

Environmental Variables ◽

Total Variance ◽

Minor Role ◽

Eutrophic Lakes ◽

Epiphytic Fauna ◽

Different Types ◽

The Impact

Complex interactions between epiphytic fauna and microbial food webs in periphyton are vital to the ecosystem ecology of shallow lakes. However, little is known about how different types of macrophyte dominated lakes may influence microbial and metazoan communities. The goal of the present study was to examine the impact of metazoan on microbial food web in three different types of lakes (Stratiotes-dominated,Ceratophyllum-dominated andPotamogeton-dominated). The results of this study suggest a strong correlations between chironomid larvae, small Metazoa and microbial communities in the periphyton of macrophyte-dominated lakes. Weak relations between food web components were found in thePotamogeton-dominated andCeratophyllum-dominated lakes, where environmental variables explained the bulk of the total variance in periphyton abundance, whereas strong predator-prey relations were noted in theStratiotes-dominated lake, where environmental variables had a minor role in the total variance in periphyton abundance. Our study contributes to knowledge of the functioning of eutrophic lakes in the current era of increasing eutrophication caused by climate change and human activity.

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Warming winters in lakes: Later ice onset promotes consumer overwintering and shapes springtime planktonic food webs

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2114840118 ◽

2021 ◽

Vol 118 (48) ◽

pp. e2114840118

Author(s):

Marie-Pier Hébert ◽

Beatrix E. Beisner ◽

Milla Rautio ◽

Gregor F. Fussmann

Keyword(s):

Food Web ◽

Global Climate ◽

Light Availability ◽

Open Water ◽

Early Winter ◽

Ecological Processes ◽

Cascading Effects ◽

Freshwater Ice ◽

Planktonic Food ◽

Sequence Of Events

Global climate warming is causing the loss of freshwater ice around the Northern Hemisphere. Although the timing and duration of ice covers are known to regulate ecological processes in seasonally ice-covered ecosystems, the consequences of shortening winters for freshwater biota are poorly understood owing to the scarcity of under-ice research. Here, we present one of the first in-lake experiments to postpone ice-cover onset (by ≤21 d), thereby extending light availability (by ≤40 d) in early winter, and explicitly demonstrate cascading effects on pelagic food web processes and phenologies. Delaying ice-on elicited a sequence of events from winter to spring: 1) relatively greater densities of algal resources and primary consumers in early winter; 2) an enhanced prevalence of winter-active (overwintering) consumers throughout the ice-covered period, associated with augmented storage of high-quality fats likely due to a longer access to algal resources in early winter; and 3) an altered trophic structure after ice-off, with greater initial springtime densities of overwintering consumers driving stronger, earlier top-down regulation, effectively reducing the spring algal bloom. Increasingly later ice onset may thus promote consumer overwintering, which can confer a competitive advantage on taxa capable of surviving winters upon ice-off; a process that may diminish spring food availability for other consumers, potentially disrupting trophic linkages and energy flow pathways over the subsequent open-water season. In considering a future with warmer winters, these results provide empirical evidence that may help anticipate phenological responses to freshwater ice loss and, more broadly, constitute a case of climate-induced cross-seasonal cascade on realized food web processes.

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Carbon flow patterns in the planktonic food web of the Gulf of Riga, the Baltic Sea: a reconstruction by the inverse method

Journal of Marine Systems ◽

10.1016/s0924-7963(99)00061-5 ◽

1999 ◽

Vol 23 (1-3) ◽

pp. 251-268 ◽

Cited By ~ 37

Author(s):

Espen Donali ◽

Kalle Olli ◽

Anna-Stiina Heiskanen ◽

Tom Andersen

Keyword(s):

Baltic Sea ◽

Food Web ◽

Inverse Method ◽

Flow Patterns ◽

Carbon Flow ◽

The Baltic Sea ◽

Planktonic Food ◽

Gulf Of Riga ◽

The Baltic

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Effects of microzooplankton and mixotrophy in an experimental planktonic food web

Limnology and Oceanography ◽

10.4319/lo.2004.49.4_part_2.1435 ◽

2004 ◽

Vol 49 (4part2) ◽

pp. 1435-1445 ◽

Cited By ~ 41

Author(s):

Robert Ptacnik ◽

Ulrich Sommer ◽

Thomas Hansen ◽

Volker Martens

Keyword(s):

Food Web ◽

Planktonic Food

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Planktonic food web structure and dynamic in freshwater marshes after a lock closing in early spring

Aquatic Sciences ◽

10.1007/s00027-014-0376-1 ◽

2014 ◽

Vol 77 (1) ◽

pp. 115-128 ◽

Cited By ~ 3

Author(s):

Hélène Masclaux ◽

Sébastien Tortajada ◽

Olivier Philippine ◽

François-Xavier Robin ◽

Christine Dupuy

Keyword(s):

Food Web ◽

Early Spring ◽

Food Web Structure ◽

Freshwater Marshes ◽

Planktonic Food ◽

Web Structure

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Biogeochemical and biological impacts of diazotroph blooms in a Low Nutrient Low Chlorophyll ecosystem: synthesis from the VAHINE mesocosm experiment (New Caledonia)

10.5194/bg-2015-668 ◽

2016 ◽

Cited By ~ 1

Author(s):

Sophie Bonnet ◽

Melika Baklouti ◽

Audrey Gimenez ◽

Hugo Berthelot ◽

Ilana Berman-Frank

Keyword(s):

Food Web ◽

N2 Fixation ◽

New Caledonia ◽

External Source ◽

Marine Ecosystems ◽

Inorganic Phosphorus ◽

Food Web Structure ◽

West Pacific ◽

Planktonic Food ◽

South West

Abstract. In marine ecosystems, N2 fixation provides the predominant external source of nitrogen (N) (140 ± 50 Tg N yr−1), contributing more than atmospheric and riverine inputs to the N supply. Yet the fate and magnitude of the newly-fixed N, or diazotroph-derived N (hereafter named DDN) in marine ecosystems is poorly understood. Moreover, it remains unclear whether the DDN is preferentially directly exported out of the photic zone, recycled by the microbial loop, and/or transferred into larger organisms, subsequently enhancing indirect particle export. These questions were investigated in the framework of the VAHINE (VAriability of vertical and tropHIc transfer of diazotroph derived N in the south wEst Pacific) project. Triplicate large volume (~50 m3) mesocosms were deployed in the tropical South West Pacific coastal ocean (New Caledonia) to maintain a stable water-mass without disturbing ambient light and temperature conditions. The mesocosms were intentionally fertilized with ~0.8 μM dissolved inorganic phosphorus (DIP) at the start of the experiment to stimulate diazotrophy. A total of 47 stocks, fluxes, enzymatic activities and diversity parameters were measured daily inside and outside the mesocosms by the 40 scientists involved in the project. The experiment lasted for 23 days and was characterized by two distinct and successive diazotroph blooms: a dominance of diatom-diazotroph associations (DDAs) during the first half of the experiment (days 2–14) followed by a bloom of UCYN-C during the second half of the experiment (days 15–23). These conditions provided a unique opportunity to compare the DDN transfer and export efficiency associated with different diazotrophs. Here we summarize the major experimental and modelling results obtained during the project and described in the VAHINE Special issue, in particular those regarding the evolution of the main standing stocks, fluxes and biological characteristics over the 23-days experiment, the contribution of N2 fixation to export fluxes, the DDN released to dissolved pool and its transfer to the planktonic food web (bacteria, phytoplankton, zooplankton). We then apply our Eco3M modelling platform further to infer the fate of DDN in the ecosystem and role of N2 fixation on productivity, food web structure and carbon export. Recommendations for future work are finally provided in the conclusion section.

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Contrasting pelagic ecosystem functioning in eastern and western Baffin Bay revealed by trophic network modeling

Elem Sci Anth ◽

10.1525/elementa.397 ◽

2020 ◽

Vol 8 ◽

Cited By ~ 2

Author(s):

Blanche Saint-Béat ◽

Brian D. Fath ◽

Cyril Aubry ◽

Jonathan Colombet ◽

Julie Dinasquet ◽

...

Keyword(s):

Carbon Cycle ◽

Food Web ◽

Biological Data ◽

The Arctic ◽

Ecosystem Structure ◽

Carbon Export ◽

Baffin Bay ◽

Planktonic Food ◽

Carbon Transfer ◽

Current Flows

Baffin Bay, located at the Arctic Ocean’s ‘doorstep’, is a heterogeneous environment where a warm and salty eastern current flows northwards in the opposite direction of a cold and relatively fresh Arctic current flowing along the west coast of the bay. This circulation affects the physical and biogeochemical environment on both sides of the bay. The phytoplanktonic species composition is driven by its environment and, in turn, shapes carbon transfer through the planktonic food web. This study aims at determining the effects of such contrasting environments on ecosystem structure and functioning and the consequences for the carbon cycle. Ecological indices calculated from food web flow values provide ecosystem properties that are not accessible by direct in situ measurement. From new biological data gathered during the Green Edge project, we built a planktonic food web model for each side of Baffin Bay, considering several biological processes involved in the carbon cycle, notably in the gravitational, lipid, and microbial carbon pumps. Missing flow values were estimated by linear inverse modeling. Calculated ecological network analysis indices revealed significant differences in the functioning of each ecosystem. The eastern Baffin Bay food web presents a more specialized food web that constrains carbon through specific and efficient pathways, leading to segregation of the microbial loop from the classical grazing chain. In contrast, the western food web showed redundant and shorter pathways that caused a higher carbon export, especially via lipid and microbial pumps, and thus promoted carbon sequestration. Moreover, indirect effects resulting from bottom-up and top-down control impacted pairwise relations between species differently and led to the dominance of mutualism in the eastern food web. These differences in pairwise relations affect the dynamics and evolution of each food web and thus might lead to contrasting responses to ongoing climate change.

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Mesoscale variations in the assemblage structure and trophodynamics of mesozooplankton communities of the Adriatic basin (Mediterranean Sea)

10.5194/bg-2021-240 ◽

2021 ◽

Author(s):

Emanuela Fanelli ◽

Samuele Menicucci ◽

Sara Malavolti ◽

Andrea De Felice ◽

Iole Leonori

Keyword(s):

Food Web ◽

Food Webs ◽

Mediterranean Sea ◽

Environmental Variables ◽

Complex Structure ◽

Assemblage Structure ◽

Trophic Levels ◽

Ecosystem Functions ◽

Food Web Structure ◽

Adriatic Basin

Abstract. Zooplankton are critical to the functioning of ocean food webs because of their utter abundance and vital ecosystem roles. Zooplankton communities are highly diverse and thus perform a variety of ecosystem functions, thus changes in their community or food web structure may provide evidence of ecosystem alteration. Assemblage structure and trophodynamics of mesozooplantkon communities were examined across the Adriatic basin, the northernmost and most productive basin of the Mediterranean Sea. Samples were collected in June–July 2019 along coast-offshore transects covering the whole western Adriatic side, consistently environmental variables were also recorded. Results showed a clear separation between samples from the northern-central Adriatic and the southern ones, with a further segregation, although less clear, of inshore vs. off-shore stations, the latter mostly dominated in the central and southern stations by gelatinous plankton. Such patterns were mainly driven by chlorophyll-a concentration (as a proxy of primary production) for northern-central stations, i.e. closer to the Po river input, and by temperature and salinity, for southern ones, with the DistLM model explaining 46 % of total variance. The analysis of stable isotopes of nitrogen and carbon allowed to identify a complex food web characterized by 3 trophic levels from herbivores to carnivores, passing through the mixed feeding behavior of omnivores, shifting from phytoplankton/detritus ingestion to microzooplankton. Trophic structure also spatially varied according to sub-area, with the northern-central sub-areas differing from each other and from the southern stations. Our results highlighted the importance of environmental variables as drivers of zooplanktonic communities and the complex structure of their food webs. Disentangling and considering such complexity is crucial to generate realistic predictions on the functioning of aquatic ecosystems, especially in high productive and, at the same time, overexploited area such as the Adriatic Sea.

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