The Experts below are selected from a list of 1500 Experts worldwide ranked by ideXlab platform
Carla Ferragut - One of the best experts on this subject based on the ideXlab platform.
-
Relationship between epipelon, Epiphyton and phytoplankton in two limnological phases in a shallow tropical reservoir with high Nymphaea coverage
Hydrobiologia, 2020Co-Authors: Thiago Rodrigues Santos, Maria Carolina Castilho, Raoul Henry, Carla FerragutAbstract:Macrophytes and phytoplankton are recognized as having roles in determining alternative stable states in shallow lakes and reservoirs, while the role of periphyton has been poorly investigated. Temporal and spatial variation of phytoplankton, epipelon and Epiphyton was examined in a shallow reservoir with high abundance of aquatic macrophytes. The relationships between algae communities and abiotic factors, macrophyte coverage and zooplankton density were also analyzed. Monthly sampling was performed in three zones of the depth gradient of the reservoir. Two phases of algal dominance were found: a phytoplankton phase and epipelon phase. The phase of phytoplankton dominance was characterized by high macrophyte coverage. Rotifera was the dominant zooplankton group in all the zones. Flagellate algae were dominant in phytoplankton, epipelon and Epiphyton. Macrophyte coverage was found to be a predictor for algal biomass. Changes in biomass and species composition were associated with macrophyte cover variation, mainly the Nymphaea . In addition to the abiotic factors, the macrophyte coverage was a determining factor for changes to the algal community, contributing to the alternation between dominance phases of phytoplankton and epipelon. The macrophyte–phytoplankton–periphyton relationship needs to be further known in shallow reservoirs, especially the role of epipelon as an alternate stable state.
-
Environmental predictors of algal community structure of plankton, epipelon and Epiphyton in a shallow tropical reservoir
Brazilian Journal of Botany, 2019Co-Authors: Thiago Rodrigues Dos Santos, Carla FerragutAbstract:Structural characteristics of algal communities can be used to access environmental conditions, but there is a great need to identify the drivers of change in all habitats. This study evaluated the spatial and temporal changes in the phytoplankton, epipelon and Epiphyton structures in a shallow reservoir. We investigated the determining factors of the structural variability and spatial differences in the species composition and algal density in the three habitats. Bimonthly samplings were carried out for determination of the limnological variables and algal communities. The rainy season was characterized by high nutrient availability and macrophyte coverage, and the communities were dominated by flagellate algae, as Chromulina elegans Doflein. The highest modification rate was found in the phytoplankton structure, followed by Epiphyton and epipelon. Despite the species co-occurrence among phytoplankton, epipelon and Epiphyton, the descriptor species presented different representativeness in communities. Planktonic and epiphytic algae were more associated with temporal variation in nutrient availability, while depth was more important for epipelic algae structuring. We conclude that the algal community in the plankton, epipelon and Epiphyton was structured by different environmental factors, but descriptor species co-occurrence suggested an interrelationship between communities in this shallow reservoir with high abundance of macrophytes.
-
Structural changes of the phytoplankton and Epiphyton in an urban hypereutrophic reservoir
Acta Limnologica Brasiliensia, 2016Co-Authors: Lucineide Maria Santana, Carla FerragutAbstract:Abstract: Aim: This study evaluated the temporal changes of phytoplankton and Epiphyton structure and their relationships with limnological factors in an urban hypereutrophic reservoir (Rasgao Reservoir, Brazil). Methods: We collected water sample and phytoplankton in different depths at two sites (dam and near tributary input) in summer and winter 2010. Epiphyton on Salvinia spp. was sampled only at site near the tributary input. We determined limnological variables and structural attributes (species composition, density, biovolume, descriptors species, diversity) for both communities. Results: Phytoplankton density and Epiphyton density and biovolume were higher in the winter (dry season), which occurred the higher nutrient concentrations and lower water flow. Chlorophyceae was dominant in the phytoplankton, except in the winter when Cyanobacteria was co-abundant. In the Epiphyton, Bacillariophyceae was dominant in the summer and Cyanobacteria in the winter. The increase in light availability and water flow can have provided high species richness and diversity in the summer. Conclusion: Temporal changes in the structure of phytoplankton and Epiphyton on Salvinia were more related to increased nutrients availability (nitrogen and phosphorus) and flow variations in a hypereutrophic reservoir. Keywords: algae community, plankton, periphyton, seasonality, urban pollution. Resumo: Objetivo: Este estudo avaliou as mudancas temporais da estrutura do fitoplâncton e do epifiton e suas relacoes com os fatores limnologicos em um reservatorio urbano hipereutrofico (Reservatorio Rasgao, Brasil). Metodos: Nos coletamos amostras de agua e fitoplâncton em diferentes profundidades em dois locais (barragem e proximo da entrada do tributario) no verao e inverno de 2010. O epifiton em Salvinia spp. foi amostrado somente no local proximo da entrada do tributario. Nos determinamos as variaveis limnologicas e os atributos estruturais (composicao de especies, densidade, biovolume, especies descritoras, diversidade) para ambas as comunidades. Resultados : A densidade do fitoplâncton e a densidade e o biovolume do epifiton foram maior no inverno (estacao seca), no qual ocorreu as maiores concentracoes de nutrientes e menor vazao. Chlorophyceae foi dominante no fitoplâncton, exceto no inverno quando Cyanobacteria foi co-abundante. No epifiton, Bacillariophyceae foi dominante no verao e Cyanobacteria no inverno. O aumento da disponibilidade de luz e da vazao podem ter favorecido a alta riqueza e diversidade de especies no verao. Conclusao : As mudancas temporais na estrutura do fitoplâncton e do epifiton em Salvinia foram mais relacionadas com o aumento na disponibilidade de nutrientes (nitrogenio e fosforo) e as variacoes na vazao em um reservatorio hipereutrofico. Palavras-chave: comunidade de algas, plâncton, perifiton, sazonalidade, poluicao urbana.
David Da Motta Marques - One of the best experts on this subject based on the ideXlab platform.
-
Epiphyton dynamics during an induced succession in a large shallow lake wind disturbance and zooplankton grazing act as main structuring forces
Hydrobiologia, 2017Co-Authors: Denise Matias De Faria, Luciana De Souza Cardoso, David Da Motta MarquesAbstract:We investigated the main structuring forces driving epiphytic algae dynamics with wind disturbances and zooplankton grazing acting as potential stressors by inducing a natural 60-day Epiphyton summer succession. We cleaned macrophytes in the subtropical shallow Mangueira Lake, southern Brazil, using soft sponges and sampled them randomly at short-term intervals. Simultaneously, we sampled and classified zooplankton from the littoral zone according to their particle ingestion size. Disturbance by wind was the main factor driving the Epiphyton succession. Tightly attached diatoms were well adapted to the system’s high mean wind velocity (15 m s−1), whereas low wind velocity (<7 m s−1) reduced community diversity. Summer storms (46.7 mm of precipitation; 29.5 m s−1 wind velocity) caused phosphorus input and favored prostrate diatoms. Epiphyton was very productive (8028.8 mg C m−2 h−1), consistent with a heterogeneous community. Small rotifers and ciliates were abundant in the water column during the study. Our data indicate that rotifers as well as other zooplankton grazed on Epiphyton, due to the positive correlation between algal diversity and rotifer abundance as well as between diatom and zooplankton biomasses, whereas Copepods and Cladocerans followed large motile diatoms in abundance. We conclude that Epiphyton is an important food source for zooplankton in Mangueira Lake.
-
Epiphyton dynamics during an induced succession in a large shallow lake: wind disturbance and zooplankton grazing act as main structuring forces
Hydrobiologia, 2016Co-Authors: Denise Matias De Faria, Luciana De Souza Cardoso, David Da Motta MarquesAbstract:We investigated the main structuring forces driving epiphytic algae dynamics with wind disturbances and zooplankton grazing acting as potential stressors by inducing a natural 60-day Epiphyton summer succession. We cleaned macrophytes in the subtropical shallow Mangueira Lake, southern Brazil, using soft sponges and sampled them randomly at short-term intervals. Simultaneously, we sampled and classified zooplankton from the littoral zone according to their particle ingestion size. Disturbance by wind was the main factor driving the Epiphyton succession. Tightly attached diatoms were well adapted to the system’s high mean wind velocity (15 m s−1), whereas low wind velocity (
Emilie Duffaud - One of the best experts on this subject based on the ideXlab platform.
-
temporal changes in essential fatty acid availability in different food sources in the littoral macrophyte zone
Hydrobiologia, 2014Co-Authors: Helene Masclaux, Gilles Bourdier, Lionel Jouve, Emilie DuffaudAbstract:In littoral environments, different food resources are available for zooplankters. In addition to seston, species may feed on biofilms growing on sediments, plants (Epiphyton), and at the air–water interface (neuston). However, despite a growing interest in these different biofilms, little is known about their food quality for microcrustaceans. In a field study, we measured changes in the food quality over time in terms of the essential fatty acid (EFA) content of different potential food sources for littoral consumers. The food quality of seston, neuston, and Epiphyton growing on three different aquatic macrophytes were assessed. Our results showed that there is an important seasonal variability within each food source. However, in the system studied, epiphytic biofilms, especially those of Ludwigia and Callitriche offered the highest food quality, in terms of EFA content, throughout the year. As the highest EFA concentrations in each food source were found consecutively, high concentrations of these physiologically important compounds are maintained in the system throughout the year. Therefore, greater diversity of food resources could affect ecosystem productivity.
-
resource partitioning among cladocerans in a littoral macrophyte zone implications for the transfer of essential compounds
Aquatic Sciences, 2014Co-Authors: Helene Masclaux, Gilles Bourdier, Lionel Jouve, Emilie Duffaud, Pascal Riera, Martin J KainzAbstract:The maintenance of species diversity in a given environment is strongly linked to resource partitioning. Littoral macrophyte zones are heterogeneous environments with high microcrustacean diversity, where zooplankton have dietary access to seston as well as organisms growing on macrophytic surfaces (Epiphyton). We conducted a field study in a macrophyte-rich backwater of the river Allier to examine how seston and Epiphyton were used as potential food sources by four dominant cladoceran species. Fatty acids were analyzed in these two food sources to assess how their differential uptake affects the trophic trajectory of essential compounds from these resources to cladocerans. Our results showed resource partitioning among the four cladocerans studied; while Eurycercus fed mostly on Epiphyton, Daphnia mostly consumed phytoplankton, and Ceriodaphnia and Simocephalus were able to forage on sestonic and epiphytic resources. Based on their polyunsaturated fatty acid (PUFA) content, it was evident that Epiphyton was of higher food quality than seston in this macrophyte-rich backwater system. Variability of PUFA compositions of seston and Epiphyton, and diversity of foraging strategies of cladoceran species, which represent the major link between microorganisms and consumers at higher trophic levels, affect dietary energy pathways and point to a variable PUFA transfer efficiency in backwater food webs.
Denise Matias De Faria - One of the best experts on this subject based on the ideXlab platform.
-
Epiphyton dynamics during an induced succession in a large shallow lake wind disturbance and zooplankton grazing act as main structuring forces
Hydrobiologia, 2017Co-Authors: Denise Matias De Faria, Luciana De Souza Cardoso, David Da Motta MarquesAbstract:We investigated the main structuring forces driving epiphytic algae dynamics with wind disturbances and zooplankton grazing acting as potential stressors by inducing a natural 60-day Epiphyton summer succession. We cleaned macrophytes in the subtropical shallow Mangueira Lake, southern Brazil, using soft sponges and sampled them randomly at short-term intervals. Simultaneously, we sampled and classified zooplankton from the littoral zone according to their particle ingestion size. Disturbance by wind was the main factor driving the Epiphyton succession. Tightly attached diatoms were well adapted to the system’s high mean wind velocity (15 m s−1), whereas low wind velocity (<7 m s−1) reduced community diversity. Summer storms (46.7 mm of precipitation; 29.5 m s−1 wind velocity) caused phosphorus input and favored prostrate diatoms. Epiphyton was very productive (8028.8 mg C m−2 h−1), consistent with a heterogeneous community. Small rotifers and ciliates were abundant in the water column during the study. Our data indicate that rotifers as well as other zooplankton grazed on Epiphyton, due to the positive correlation between algal diversity and rotifer abundance as well as between diatom and zooplankton biomasses, whereas Copepods and Cladocerans followed large motile diatoms in abundance. We conclude that Epiphyton is an important food source for zooplankton in Mangueira Lake.
-
Epiphyton dynamics during an induced succession in a large shallow lake: wind disturbance and zooplankton grazing act as main structuring forces
Hydrobiologia, 2016Co-Authors: Denise Matias De Faria, Luciana De Souza Cardoso, David Da Motta MarquesAbstract:We investigated the main structuring forces driving epiphytic algae dynamics with wind disturbances and zooplankton grazing acting as potential stressors by inducing a natural 60-day Epiphyton summer succession. We cleaned macrophytes in the subtropical shallow Mangueira Lake, southern Brazil, using soft sponges and sampled them randomly at short-term intervals. Simultaneously, we sampled and classified zooplankton from the littoral zone according to their particle ingestion size. Disturbance by wind was the main factor driving the Epiphyton succession. Tightly attached diatoms were well adapted to the system’s high mean wind velocity (15 m s−1), whereas low wind velocity (
Helene Masclaux - One of the best experts on this subject based on the ideXlab platform.
-
temporal changes in essential fatty acid availability in different food sources in the littoral macrophyte zone
Hydrobiologia, 2014Co-Authors: Helene Masclaux, Gilles Bourdier, Lionel Jouve, Emilie DuffaudAbstract:In littoral environments, different food resources are available for zooplankters. In addition to seston, species may feed on biofilms growing on sediments, plants (Epiphyton), and at the air–water interface (neuston). However, despite a growing interest in these different biofilms, little is known about their food quality for microcrustaceans. In a field study, we measured changes in the food quality over time in terms of the essential fatty acid (EFA) content of different potential food sources for littoral consumers. The food quality of seston, neuston, and Epiphyton growing on three different aquatic macrophytes were assessed. Our results showed that there is an important seasonal variability within each food source. However, in the system studied, epiphytic biofilms, especially those of Ludwigia and Callitriche offered the highest food quality, in terms of EFA content, throughout the year. As the highest EFA concentrations in each food source were found consecutively, high concentrations of these physiologically important compounds are maintained in the system throughout the year. Therefore, greater diversity of food resources could affect ecosystem productivity.
-
resource partitioning among cladocerans in a littoral macrophyte zone implications for the transfer of essential compounds
Aquatic Sciences, 2014Co-Authors: Helene Masclaux, Gilles Bourdier, Lionel Jouve, Emilie Duffaud, Pascal Riera, Martin J KainzAbstract:The maintenance of species diversity in a given environment is strongly linked to resource partitioning. Littoral macrophyte zones are heterogeneous environments with high microcrustacean diversity, where zooplankton have dietary access to seston as well as organisms growing on macrophytic surfaces (Epiphyton). We conducted a field study in a macrophyte-rich backwater of the river Allier to examine how seston and Epiphyton were used as potential food sources by four dominant cladoceran species. Fatty acids were analyzed in these two food sources to assess how their differential uptake affects the trophic trajectory of essential compounds from these resources to cladocerans. Our results showed resource partitioning among the four cladocerans studied; while Eurycercus fed mostly on Epiphyton, Daphnia mostly consumed phytoplankton, and Ceriodaphnia and Simocephalus were able to forage on sestonic and epiphytic resources. Based on their polyunsaturated fatty acid (PUFA) content, it was evident that Epiphyton was of higher food quality than seston in this macrophyte-rich backwater system. Variability of PUFA compositions of seston and Epiphyton, and diversity of foraging strategies of cladoceran species, which represent the major link between microorganisms and consumers at higher trophic levels, affect dietary energy pathways and point to a variable PUFA transfer efficiency in backwater food webs.