Homogenization of diatom assemblages is driven by eutrophication in tropical reservoirs

2021 ◽  
pp. 117778
Author(s):  
Stéfano Zorzal-Almeida ◽  
Elaine C.Rodrigues Bartozek ◽  
Denise C. Bicudo
Keyword(s):  
Diatom Assemblages ◽  
Tropical Reservoirs

Environmental and spatial drivers of diatom assemblages in the water column and surface sediment of tropical reservoirs

2019 ◽  
Vol 62 (3) ◽  
pp. 245-257
Author(s):  
Elaine C. R. Bartozek ◽  
Angela M. da Silva-Lehmkuhl ◽  
Irene Gregory-Eaves ◽  
Denise C. Bicudo
Keyword(s):  
Water Column ◽  
Surface Sediment ◽  
Diatom Assemblages ◽  
Tropical Reservoirs

scholarly journals Diatom assemblages (Bacillariophyta) in six tropical reservoirs from southeast Brazil: species composition and spatial and temporal variation patterns

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Gisele Carolina Marquardt ◽  
Carlos Eduardo de Mattos Bicudo ◽  
Thelma Alvim Veiga Ludwig ◽  
Luc Ector ◽  
Carlos E. Wetzel
Keyword(s):  
Water Quality ◽  
Species Composition ◽  
Sao Paulo ◽  
Spatial And Temporal Variation ◽  
São Paulo ◽  
Diatom Assemblages ◽  
Tropical Reservoirs ◽  
Southeast Brazil ◽  
Variation Patterns ◽  
First Time

Abstract Aim Relationships between species composition and variation patterns in diatom assemblages over six tropical reservoirs located in Southeast Brazil were explored. Methods Surface-sediment and phytoplankton diatom assemblages were determined and Canonical Correspondence Analysis was used to verify the set of environmental variables that best explain the species composition variation among sites. Results A total of 28 diatom taxa representing 20 genera were identified using light and scanning electron microscopy. Information on their ecological preferences was also provided. Humidophila biscutella is reported for the first time in Brazil whereas Sellaphora sassiana and Humidophila brekkaensis are reported for the first time in São Paulo State. Three groups of potential water quality indicators were delineated: the first suggests oligotrophic conditions, the second is related to cold waters with low luminosity in a mixing regime, and the third is a small group of tolerant species occurring in water with high conductivity, pH and total phosphorus conditions. Conclusion present study provided the first insight into the general diatom communities over six tropical reservoirs in Southeast Brazil and provided information on their ecology and distribution aiming bioassessment. The potential of water quality indicator diatom groups here outlined are in line with those reported in the literature and reinforce the importance of PEJU for the maintenance of ecological quality of reservoirs and reference conditions for the Metropolitan Region of São Paulo water sources.

Holocene diatom assemblages from Dunderbukhta sediments, West Svalbard

2019 ◽  
pp. 242-245
Author(s):  
Ksenya V. Poleshchuk ◽  
Zinaida V. Pushina ◽  
Sergey R. Verkulich
Keyword(s):  
Environmental Changes ◽  
Ecological Groups ◽  
Diatom Assemblages ◽  
Diatom Analysis ◽  
Diatom Flora ◽  
Sediment Samples ◽  
Ecological Zones ◽  
Middle Holocene ◽  
Temperature Trends

The diatom analysis results of sediment samples from Dunderbukta area (Wedel Jarlsberg Land, West Svalbard) are presented in this paper. The diatom flora consists of four ecological groups, which ratio indicates three ecological zones. These zones show environmental changes of the area in early–middle Holocene that is demonstrating periods of regression and temperature trends.

Diatoms in the Early Valdai (Weichselian) sediments in Lake Ladoga basin

2019 ◽  
pp. 225-228
Author(s):  
Anna V. Ludikova
Keyword(s):  
Species Diversity ◽  
High Energy ◽  
Lake Ladoga ◽  
Diatom Assemblages ◽  
Marine Diatoms ◽  
Selective Preservation

The pioneer diatom study of the Early Weichselian (Valdai) sediments in Lake Ladoga basin was performed. The specifics of the diatom assemblages (co-occurrence of ecologically incompatible taxa, poor species diversity, low diatom concentration and selective preservation) suggest that during the Early Weichselian time intense erosion of previously deposited marine Eemian (Mikulino) sediments prevailed, which resulted in re-deposition of marine diatoms. The sedimentation took place in high-energy environments unfavorable for diatom accumulation and preservation.

Composition and distribution of diatom assemblages in the surface sediments of the Bering Sea

2013 ◽  
Vol 24 (3) ◽  
pp. 167 ◽  
Author(s):  
Lixia SHAO ◽  
Rongcheng LIN ◽  
Yahui GAO ◽  
Dingyong HUANG
Keyword(s):  
Bering Sea ◽  
Surface Sediments ◽  
Diatom Assemblages ◽  
The Bering Sea

DIATOM ASSEMBLAGES IN COASTAL SURFACE SEDIMENTS IN SOUTHEAST OF CHINA

2012 ◽  
Vol 32 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Chun CHEN ◽  
Guangtao ZHAO ◽  
Min CHEN ◽  
Binbin LAN ◽  
Dongzhao LAN ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Diatom Assemblages

An Assessment of Environmental Changes in Three Lakes from King's County (Nova Scotia, Canada) Using Diatom-Based Paleolimnological Techniques

2008 ◽  
Vol 43 (2-3) ◽  
pp. 85-98 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Brian K. Ginn ◽  
Brian F. Cumming ◽  
John P. Smol
Keyword(s):  
Nova Scotia ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Lake Management ◽  
River System ◽  
210Pb Dating ◽  
Hydroelectric Power ◽  
Diatom Assemblages ◽  
Shoreline Development ◽  
Before And After

Abstract Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by 210Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.

scholarly journals Late-Holocene diatom community response to climate driven chemical changes in a small, subarctic lake, Northwest Territories, Canada

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Paul B Hamilton ◽  
Scott J Hutchinson ◽  
R Timothy Patterson ◽  
Jennifer M Galloway ◽  
Nawaf A Nasser ◽  
...  
Keyword(s):  
Iron Age ◽  
Biological Diversity ◽  
Regional Climate ◽  
Natural Aging ◽  
Community Response ◽  
Warm Period ◽  
Ice Age ◽  
Diatom Assemblages ◽  
Subarctic Lake ◽  
Over Time

The paleolimnological record of diatoms and climate, spanning the last 2800 years, was investigated in a small subarctic lake (Pocket Lake) that from AD 1948 to 2004 was contaminated by gold smelting waste. An age-depth model was constructed using a combination of 210Pb, 14C, and tephra to determine a 2800 year history of lake ontogeny (natural aging), biological diversity, and regional climate variability. Diatoms form six strong paleoecological assemblages over time in response to changes in local hydrological and sedimentological conditions (including metals). Selected environmental variables explained 28.8% of the variance in the diatom assemblages, with Fe, Ca, and sediment end member distribution being important indicators. The diatom assemblages correlated to the Iron Age Cold Epoch (2800–2300 cal BP), Roman Warm Period (2250–1610 cal BP), Dark Age Cold Period (1500–1050 cal BP), Medieval Climate Anomaly (ca. 1100–800 cal BP), and the Little Ice Age (800–200 cal BP). The disappearance of Staurosira venter highlights the change from the Iron Age Cold Epoch to the Roman Warm Period. After deposition of the White River Ash (833–850 CE; 1117–1100 cal BP), transition to circumneutral conditions was followed in tandem by a transition to planktic influenced communities. Ten discrete peaks of Cu, Pb, and Zn were observed and attributed to soluble mobility from catchment soils through enhanced seepage and spring snowmelt. The prominent metal spikes were aligned with increases in Brachysira neoexilis. Downward mobilization of arsenic and antimony from contaminated surficial sediments highlight the problem of post depositional industrial contamination of paleosediments. Results demonstrate that paleoclimatic changes in the region, modulated by solar radiation, impacted temperature and precipitation in the lake catchment, influencing temporal shifts in diatom ecology. Changes in diatom taxa richness provided valuable information on the relative influence of water quality (planktic taxa) and sediment input (benthic taxa). The diatom assemblage succession also provides evidence that natural aging over time has played a role in the ecological evolution of the lake.

scholarly journals Drivers of Macrophyte and Diatom Diversity in a Shallow Hypertrophic Lake

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1569
Author(s):  
Kateřina Šumberová ◽  
Ondřej Vild ◽  
Michal Ducháček ◽  
Martina Fabšičová ◽  
Jan Potužák ◽  
...  
Keyword(s):  
Fish Farming ◽  
Spatial Diversity ◽  
Spatiotemporal Variability ◽  
Water Level Fluctuations ◽  
Nutrient Requirements ◽  
Diatom Assemblages ◽  
Climatic Extremes ◽  
Growing Seasons ◽  
High Species Richness ◽  
Different Parts

We studied macrophyte and diatom assemblages and a range of environmental factors in the large hypertrophic Dehtář fishpond (Southern Bohemia, Czech Republic) over the course of several growing seasons. The spatial diversity of the environment was considered when collecting diatoms and water samples in three distinct parts of the fishpond, where automatic sensor stations continually measuring basic factors were established. Macrophytes were mapped in 30 segments of the fishpond littoral altogether. High species richness and spatiotemporal variability were found in assemblages of these groups of autotrophs. Water level fluctuations, caused by the interaction of fish farming management and climatic extremes, were identified as one of the most important factors shaping the structure and species composition of diatom and macrophyte assemblages. The distance of the sampling sites from large inflows reflected well the spatial variability within the fishpond, with important differences in duration of bottom drainage and exposure to disturbances in different parts of the fishpond. Disturbances caused by intensive wave action are most probably a crucial factor allowing the coexistence of species with different nutrient requirements under the hypertrophic conditions of the Dehtář fishpond. Due to a range of variables tested and climatic extremes encountered, our study may be considered as a basis for predictive model constructions in similar hypertrophic water bodies under a progressing climate change.

Sign in / Sign up

Export Citation Format

Share Document