scholarly journals Comparison of FlowCAM and microscope biovolume measurements for a diverse freshwater phytoplankton community

2019 ◽  
Vol 41 (6) ◽  
pp. 849-864 ◽  
Author(s):  
Allison R Hrycik ◽  
Angela Shambaugh ◽  
Jason D Stockwell
Keyword(s):  
Processing Speed ◽  
Phytoplankton Community ◽  
Taxonomic Resolution ◽  
Natural Unit ◽  
Freshwater Phytoplankton ◽  
Phytoplankton Communities ◽  
Genus Richness ◽  
Freshwater System ◽  
Rapid Processing ◽  
Number Of Particles

Abstract FlowCAM combines flow cytometry and imaging to rapidly enumerate, classify and measure particles. The instrument potentially increases processing speed of phytoplankton samples. FlowCAM, however, requires extensive comparison to microscopy before incorporation into monitoring and research. Past studies have compared FlowCAM and microscopy results for mostly marine rather than freshwater phytoplankton communities. We compared phytoplankton biovolume, density and taxonomic classifications between FlowCAM and microscopy for 113 samples from Lake Champlain, USA—a large freshwater system with diverse phytoplankton. Total biovolume estimates from FlowCAM were higher than microscope biovolumes due to higher individual particle biovolumes. Biovolume relationships, however, were closely correlated between the two methods. Shape-specific biovolumes from FlowCAM images slightly improved estimates compared to area-based biovolumes. Diatoms and filamentous cyanobacteria showed the strongest relationships between FlowCAM and microscope biovolumes. Microscope natural unit counts were generally higher than FlowCAM counts. Genus richness was weakly related between FlowCAM and microscopy, demonstrating a potential tradeoff between finer taxonomic resolutions with a microscope versus the higher number of particles processed with FlowCAM. Both methods produced reproducible biovolumes with replicate samples. We conclude that microscopy is more reliable when fine taxonomic resolution is needed and FlowCAM is suitable for rapid processing of major phytoplankton groups.

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Algal Biomass ◽  
Phytoplankton Community ◽  
Seasonal Pattern ◽  
Principal Component ◽  
Lake Ontario ◽  
Dominant Group ◽  
Phytoplankton Communities ◽  
Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

Factors influencing the growth of Mougeotia in experimentally acidified mesocosms

2000 ◽  
Vol 57 (3) ◽  
pp. 538-547 ◽  
Author(s):  
Jennifer L Klug ◽  
Janet M Fischer
Keyword(s):  
Inorganic Carbon ◽  
Phytoplankton Community ◽  
Dissolved Inorganic Carbon ◽  
Abiotic Factors ◽  
Minor Role ◽  
Little Rock ◽  
Factors Associated ◽  
Phytoplankton Communities ◽  
Mesocosm Experiments ◽  
Potential Factors

Acidification causes profound changes in species composition in aquatic systems. We conducted mesocosm experiments in three northern Wisconsin lakes (Trout Lake, Little Rock - Reference, Little Rock - Treatment) to test how different phytoplankton communities respond to acidification. Major differences exist among these lakes in water chemistry and phytoplankton community composition. In each lake, three pH treatments (control, press (sustained pH 4.7), and pulse (alternating pH 4.7 and ambient pH)) were maintained for 6 weeks. We observed a striking increase in species in the genus Mougeotia in all systems. Mougeotia is a filamentous green alga often found in acidified lakes. The magnitude of the Mougeotia increase differed among lakes and treatments, and we used an autoregressive model to identify potential factors responsible for these differences. Our results suggest that biotic factors such as competition with other algae played a relatively minor role in regulating Mougeotia dynamics. Instead, pH and abiotic factors associated with changes in pH (e.g., dissolved inorganic carbon) were important predictors of Mougeotia dynamics.

scholarly journals Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean

2014 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh
Keyword(s):  
Community Structure ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Phytoplankton Community ◽  
Phytoplankton Community Structure ◽  
Western Arctic Ocean ◽  
Phytoplankton Communities ◽  
Ice Retreat ◽  
Western Arctic ◽  
Sea Ice Retreat

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analysed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years–the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.

scholarly journals Feeding patterns in Eubranchipus grubii (Dybowski 1860) (Branchiopoda: Anostraca) and its potential influence on the phytoplankton communities of vernal pools

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Sofia Celewicz ◽  
Michał Jan Czyż ◽  
Bartłomiej Gołdyn
Keyword(s):  
Cell Volume ◽  
Phytoplankton Community ◽  
Grazing Pressure ◽  
Potential Influence ◽  
Filter Feeder ◽  
Algal Communities ◽  
Phytoplankton Communities ◽  
Fairy Shrimps ◽  
The Mean ◽  
And Control

Filtration patterns in the fairy shrimp Eubranchipus grubii were analysed under laboratory conditions using water containing phytoplankton from their actual locality in western Poland. After 48 hours of feeding, we compared the structure of algal communities in water samples in treatments with males, females and control. The mean filtration rate for E. grubii was relatively high (14,488 mL h-1) in comparison to other crustacean filter feeders and was higher for females than for males. Fairy shrimps grazed effectively on all 11 dominant phytoplankton taxa and there was no sign of overall preferences with regard to taxon, cell volume, length or shape. Female fairy shrimps removed significantly more cells of three taxa (Cryptomonas erosa, C. ovata and Trachelomonas volvocina). The differences between sexes did not depend on the cell volume or length of particular phytoplankton taxa but were significantly related to their initial abundance, initial biomass and shape. The higher the abundance and biomass of the algal taxa, the more intensively it was grazed by females than by males. Females were also observed to graze more on spherical and elongated cells. In conclusion, our results show E. grubii to be an effective, generalist filter feeder capable of significantly influencing the phytoplankton community of a vernal pool. Possible implications of such grazing pressure are also discussed.

scholarly journals Phytoplankton community structure in Menjer Lake, Central Java

2021 ◽  
Vol 869 (1) ◽  
pp. 012037
Author(s):  
F Sulawesty ◽  
G P Yoga ◽  
L Subehi ◽  
R Rosidah
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Nutrient Content ◽  
Cell Counting ◽  
Phytoplankton Community Structure ◽  
Nitrogen And Phosphorus ◽  
Central Java ◽  
Phytoplankton Communities ◽  
Ecological Pressure

Abstract The occurrence of land changes around Lake Menjer, Central Java Province will affect the condition of water quality subsequently will affect biota, including phytoplankton. The purposes of study was to analyze the composition and abundance of phytoplankton in Menjer Lake regarding to nutrient content i.e. nitrogen and phosphorus. Observations on the phytoplankton community were conducted in July and October 2019 at six locations in Menjer Lake. Water samples were taken at the water surface as much as 10 L filtered using plankton net. Identification was carried out under the inverted microscope Diaphot 300. The abundance was calculated using the Sedgwick Rafter cell counting (SRCC) method. Analysis of the phytoplankton community structure was derived by calculating the Diversity Index, Evenness Index, and Simpson Dominance Index. The nutrient content in Menjer Lake influences the structure of phytoplankton communities quantitatively and qualitatively. Observation showed that the diversity of phytoplankton was low and there was one species dominanted, the result explained that the phytoplankton community in Menjer Lake is unstable and there is ecological pressure on the community. It can be concluded that the improvement of environmental conditions around Menjer Lake is the basis for the sustainable management of Menjer Lake.

scholarly journals Summer aspect of phytoplankton communities in some Montenegrin lakes: Are there changes after more than two decades?

2012 ◽  
Vol 64 (2) ◽  
pp. 745-755
Author(s):  
Jelena Rakocevic
Keyword(s):  
Water Quality ◽  
Sustainable Management ◽  
Aquatic Ecosystems ◽  
Phytoplankton Community ◽  
Management Plan ◽  
Phytoplankton Composition ◽  
Qualitative And Quantitative ◽  
Environmental Monitoring System ◽  
Phytoplankton Communities ◽  
Second Period

Qualitative and quantitative phytoplankton compositions of 10 Montenegrin lakes were investigated in the summer of 2007. The obtained results were compared with a previous study-period that was undertaken two decades ago. In the first period, diatoms numerically dominated the phytoplankton community in all studied lakes, while in the second period, the same was observed only in three of the ten lakes; in other studied lakes the relative contributions of green algae, dinoflagellates and/or cyanobacteria increased, while the contribution of diatoms decreased. The shift observed in phytoplankton composition and diversity in some of the studied lakes indicates an increase in the trophic level over the two decades. The sustainable management plan of the aquatic ecosystems in Montenegro should include the establishment of an environmental monitoring system in order to record any alterations that may take place in water quality.

scholarly journals Freshwater phytoplankton diversity: models, drivers and implications for ecosystem properties

Hydrobiologia ◽  
2020 ◽  
Vol 848 (1) ◽  
pp. 53-75 ◽  
Author(s):  
Gábor Borics ◽  
András Abonyi ◽  
Nico Salmaso ◽  
Robert Ptacnik
Keyword(s):  
Phytoplankton Community ◽  
Species Coexistence ◽  
Molecular Tools ◽  
Lake Ecosystems ◽  
Phytoplankton Diversity ◽  
Freshwater Phytoplankton ◽  
Phytoplankton Ecology ◽  
Ecological Theories ◽  
Insight Into

AbstractOur understanding on phytoplankton diversity has largely been progressing since the publication of Hutchinson on the paradox of the plankton. In this paper, we summarise some major steps in phytoplankton ecology in the context of mechanisms underlying phytoplankton diversity. Here, we provide a framework for phytoplankton community assembly and an overview of measures on taxonomic and functional diversity. We show how ecological theories on species competition together with modelling approaches and laboratory experiments helped understand species coexistence and maintenance of diversity in phytoplankton. The non-equilibrium nature of phytoplankton and the role of disturbances in shaping diversity are also discussed. Furthermore, we discuss the role of water body size, productivity of habitats and temperature on phytoplankton species richness, and how diversity may affect the functioning of lake ecosystems. At last, we give an insight into molecular tools that have emerged in the last decades and argue how it has broadened our perspective on microbial diversity. Besides historical backgrounds, some critical comments have also been made.

Development of Embedded Laser Marking Controller Based on ARM9

2013 ◽  
Vol 772 ◽  
pp. 407-411
Author(s):  
Yu Fang ◽  
Dong Yun Wang ◽  
Qi Wei Yu ◽  
Yang Xiu Wei
Keyword(s):  
Control Systems ◽  
Processing Speed ◽  
Processing Capacity ◽  
Laser Marking ◽  
Laser Drivers ◽  
Rapid Processing

The existing laser marking control systems are mainly based on PC and PCI laser drivers. PC is used for editing marking information and extracting marking data. The rapid processing capacity of PC makes the laser making machine achieve faster processing speed. However, it cannot be used in the outdoors and bad situations. In older to make the laser marking system widely adapt to various environments, an embedded laser marking controller is developed. It is based on ARM9 and LINUX. It can be easily operated and can achieve wonderful marking.

scholarly journals High-resolution underway measurements of phytoplankton photosynthesis and abundance as an innovative addition to water quality monitoring programs

Ocean Science ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 1267-1285 ◽  
Author(s):  
Hedy M. Aardema ◽  
Machteld Rijkeboer ◽  
Alain Lefebvre ◽  
Arnold Veen ◽  
Jacco C. Kromkamp
Keyword(s):  
High Resolution ◽  
Spatial Patterns ◽  
North Sea ◽  
Phytoplankton Community ◽  
Spatial And Temporal Variability ◽  
Good Representation ◽  
Low Resolution ◽  
Monitoring Programs ◽  
Phytoplankton Communities ◽  
Phytoplankton Photosynthesis

Abstract. Marine waters can be highly heterogeneous both on a spatial and temporal scale, yet monitoring programs currently rely primarily on low-resolution methods. This potentially leads to undersampling. This study explores the potential of two high-resolution methods for monitoring phytoplankton dynamics: fast repetition rate fluorometry for information on phytoplankton photosynthesis and productivity and automated scanning flow cytometry for information on phytoplankton abundance and community composition. These methods were tested in combination with an underway Ferrybox system during four cruises on the Dutch North Sea in April, May, June, and August 2017. The high-resolution methods were able to visualize both the spatial and temporal variability of the phytoplankton community in the Dutch North Sea. Spectral cluster analysis was applied to objectively interpret the multitude of parameters and visualize potential spatial patterns. This resulted in the identification of biogeographic regions with distinct phytoplankton communities, which varied per cruise. Our results clearly show that the sampling based on fixed stations does not give a good representation of the spatial patterns, showing the added value of underway high-resolution measurements. To fully exploit the potential of the tested high-resolution measurement setup, methodological constraints need further research. Among these constraints are accounting for the diurnal cycle in photophysiological parameters concurrent to the spatial variation, better predictions of the electron requirement for carbon fixation to estimate gross primary productivity, and the identification of more flow cytometer clusters with informative value. Nevertheless, the richness of additional information provided by high-resolution methods can improve existing low-resolution monitoring programs towards a more precise and ecosystemic ecological assessment of the phytoplankton community and productivity.

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