Response of Phytoplankton in Acidic Lakes in Ontario to Whole-Lake Neutralization

1990 ◽  
Vol 47 (2) ◽  
pp. 422-431 ◽  
Author(s):  
Lewis A. Molot ◽  
L. Heintsch ◽  
K. H. Nicholls

Changes in phytoplankton community composition were examined in two acidic lakes in Ontario, Bowland and Trout Lakes, to determine whether neutralization (and subsequent stocking with lake trout (Salvelinus namaycush) in the case of Bowland Lake) would reverse acidic characteristics. Miskokway Lake was monitored as an untreated reference lake. Analysis of community percentage similarity showed that year-to-year variability in phytoplankton community structure would have been low in the absence of neutralization. While changes in phytoplankton biovolumes or chlorophyll a concentrations after neutralization were not significant, there were several taxonomic changes: (1) the shift in the Bowland Lake phytoplankton community away from dominance by the cyanophyte, Rhabdoderma, and (2) the dominance of the prymnesiophyte Chrysochromulina breviturrita in the Bowland Lake phytoplankton community in 1985 2 yr after neutralization. It is likely that the major phytoplankton taxonomic changes were direct responses to chemical changes. These results suggest that structural changes (taxonomic) maintained stability of the phytoplankton communities under chemical stress (in terms of standing crop).

2014 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh

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.


2021 ◽  
Vol 869 (1) ◽  
pp. 012037
Author(s):  
F Sulawesty ◽  
G P Yoga ◽  
L Subehi ◽  
R Rosidah

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.


2014 ◽  
Vol 11 (6) ◽  
pp. 8259-8324 ◽  
Author(s):  
M. Lasbleiz ◽  
K. Leblanc ◽  
S. Blain ◽  
J. Ras ◽  
V. Cornet-Barthaux ◽  
...  

Abstract. The particulate matter distribution and phytoplankton community structure of the iron-fertilized Kerguelen region were investigated in early austral spring (October–November 2011) during the KEOPS2 cruise. The iron-fertilized region was characterized by a complex mesoscale circulation resulting in a patchy distribution of particulate matter. Integrated concentrations over 200 m ranged from 72.2 to 317.7 mg m−2 for chlorophyll a, 314 to 744 mmol m−2 for biogenic silica (BSi), 1106 to 2268 mmol m−2 for particulate organic carbon, 215 to 436 mmol m−2 for particulate organic nitrogen, and 29.3 to 39.0 mmol m−2 for particulate organic phosphorus. Three distinct high biomass areas were identified: the coastal waters of Kerguelen Islands, the easternmost part of the study area in the Polar Front Zone, and the southeastern Kerguelen Plateau. As expected from previous artificial and natural iron-fertilization experiments, the iron-fertilized areas were characterized by the development of large diatoms revealed by BSi size–fractionation and HPLC pigment signatures, whereas the iron-limited reference area was associated to a low biomass dominated by a mixed (nanoflagellates and diatoms) phytoplankton assemblage. A major difference from previous artificial iron fertilization studies was the observation of much higher Si : C, Si : N, and Si : P ratios (respectively 0.31 ± 0.16, 1.6 ± 0.7 and 20.5 ± 7.9) in the iron-fertilized areas compared to the iron-limited reference station (respectively 0.13, 1.1, 5.8). A second difference is the patchy response of the elemental composition of phytoplankton communities to large scale natural iron fertilization. Comparison to the previous KEOPS1 cruise also allowed to address the seasonal dynamics of phytoplankton bloom over the southeastern plateau. From POC, PON, and BSi evolutions, we showed that the elemental composition of the particulate matter also varies at the seasonal scale. This temporal evolution followed changes of the phytoplankton community structure as well as major changes in the nutrient stocks progressively leading to silicic acid exhaustion at the end of the productive season. Our observations suggest that the specific response of phytoplankton communities under natural iron fertilization is much more diverse than what has been regularly observed in artificial iron fertilization experiments and that the elemental composition of the bulk particulate matter reflects phytoplankton taxonomic structure rather than being a direct consequence of iron availability.


2012 ◽  
Vol 23 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Simone Casali ◽  
Maria do Carmo Calijuri ◽  
Bernard Barbarisi ◽  
Vivian Fróes Renó ◽  
Adriana Gomes Affonso ◽  
...  

AIM: This paper examines the effect of the extreme water level change in 2009 on the structure and diversity of the phytoplankton communities in lakes of the Lower Amazon Floodplain, and compares it to phytoplankton community structure data reported in the literature for 2002 and 2003 high water periods, closer to the normal hydrological conditions. METHODS: Sub-surface integrated water samples for phytoplankton and chlorophyll-a analyses were collected during high and low water phases in 2009. Water temperature (°C), pH, turbidity (NTU) and electrical conductivity (µS.m-1) were measured, and the Shannon diversity index was calculated. RESULTS: The results showed striking differences in taxonomic composition between phases (high and low) and also between normal (2002 and 2003) and extreme (2009) hydrological conditions, all related to the flood pulse intensity. CONCLUSIONS: Extreme water level fluctuations can result in shifts in phytoplankton community structure and diversity. This work represents a valuable contribution to phytoplankton research since presents the community structure under extreme hydrological events in the Amazon floodplain.


2021 ◽  
Vol 20 (4A) ◽  
pp. 21-33
Author(s):  
Huynh Thi Ngoc Duyen ◽  
Tran Thi Minh Hue ◽  
Tran Thi Le Van ◽  
Phan Tan Luom ◽  
Nguyen Ngoc Lam ◽  
...  

Phytoplankton in coastal waters are important for the evaluation of either biodiversity or environmental impacts because of this highly vulnerable ecosystem. Seasonal and annual changes in the phytoplankton community structure in Quang Ngai waters during the period 2015 to 2019 were analyzed to assess the phytoplankton diversity and reveal possible causes of these changes. A total of 366 phytoplankton taxa belonging to 10 classes were identified throughout this present study. The highest species number was found in 2019 with 295 taxa, followed by those in 2015 (247), 2017 (185), and 2018 (99). The waters of Ly Son transect showed the highest diversity and most stable phytoplankton communities in both dry and rainy seasons, whereas the stations of Quang Ngai coast revealed high variability of the communities. All diversity indices including Margalef, Pielou, Shannon, Simpson did not reflect well differences in average values but a certain degree of variances, indicating possible environmental impacts. During the study time, there were blooms of certain diatom species including Skeletonema spp. in 2015 and Pseudo-nitzschia spp. in 2019. Analysis of a diatoms index, Centric/Pennate ratio, indicated that the waters were in eutrophic status with a decreasing trend from the coast area to Ly Son island in 2015 and 2019. This research built up fundamental data on phytoplankton communities for Quang Ngai province. The Centric/Pennate diatom index and diversity would be used as indicators for environmental changes and their values provided warning of eutrophication in this coastal waters including the water surrounding Ly Son island.


2013 ◽  
Vol 10 (9) ◽  
pp. 15153-15180 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh

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 analyzed 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.


2006 ◽  
Vol 3 (4) ◽  
pp. 585-606 ◽  
Author(s):  
E. Litchman ◽  
C. A. Klausmeier ◽  
J. R. Miller ◽  
O. M. Schofield ◽  
P. G. Falkowski

Abstract. Phytoplankton community composition profoundly affects patterns of nutrient cycling and the dynamics of marine food webs; therefore predicting present and future phytoplankton community structure is crucial to understand how ocean ecosystems respond to physical forcing and nutrient limitations. We develop a mechanistic model of phytoplankton communities that includes multiple taxonomic groups (diatoms, coccolithophores and prasinophytes), nutrients (nitrate, ammonium, phosphate, silicate and iron), light, and a generalist zooplankton grazer. Each taxonomic group was parameterized based on an extensive literature survey. We test the model at two contrasting sites in the modern ocean, the North Atlantic (North Atlantic Bloom Experiment, NABE) and subarctic North Pacific (ocean station Papa, OSP). The model successfully predicts general patterns of community composition and succession at both sites: In the North Atlantic, the model predicts a spring diatom bloom, followed by coccolithophore and prasinophyte blooms later in the season. In the North Pacific, the model reproduces the low chlorophyll community dominated by prasinophytes and coccolithophores, with low total biomass variability and high nutrient concentrations throughout the year. Sensitivity analysis revealed that the identity of the most sensitive parameters and the range of acceptable parameters differed between the two sites. We then use the model to predict community reorganization under different global change scenarios: a later onset and extended duration of stratification, with shallower mixed layer depths due to increased greenhouse gas concentrations; increase in deep water nitrogen; decrease in deep water phosphorus and increase or decrease in iron concentration. To estimate uncertainty in our predictions, we used a Monte Carlo sampling of the parameter space where future scenarios were run using parameter combinations that produced acceptable modern day outcomes and the robustness of the predictions was determined. Change in the onset and duration of stratification altered the timing and the magnitude of the spring diatom bloom in the North Atlantic and increased total phytoplankton and zooplankton biomass in the North Pacific. Changes in nutrient concentrations in some cases changed dominance patterns of major groups, as well as total chlorophyll and zooplankton biomass. Based on these scenarios, our model suggests that global environmental change will inevitably alter phytoplankton community structure and potentially impact global biogeochemical cycles.


2014 ◽  
Vol 955-959 ◽  
pp. 1363-1367 ◽  
Author(s):  
Rui Ye ◽  
Xin Qian ◽  
Kun Shan ◽  
Hai Long Gao

Temporal distribution phytoplankton community structure in a shallow lake, Lake Taihu, China, was investigated from 2010 to 2011 on a monthly basis at 9 sampling stations. The results showed that phytoplankton communities primarily consist of cyanobacteria, chlorophyta and bacillariophyta in Lake Taihu. A significant change in phytoplankton community was observed in both years: cyanobacteria hold an overwhelming dominance in summer and autumn, chloraphyta and bacillariophyta occupied the certain proportion only when the cyanobacterial bloom was declined in winter and early spring. The maximum abundance value of cyanobacteria, chlorophyta and bacillariophyta appeared at June, 2010, July, 2011 and Feb, 2011, respectively. The present study is a continuation and complement in long-term research of Lake Taihu, which provides scientific foundation for further research of the lake.


2018 ◽  
Vol 40 (1) ◽  
pp. 13-24
Author(s):  
Huynh Thi Ngoc Duyen ◽  
Phan Tuan Luom ◽  
Tran Thi Le Van ◽  
Nguyen Thi Mai Anh ◽  
Tran Thi Minh Hue ◽  
...  

Impacts of El Niño Southern Oscillation (ENSO) on the phytoplankton community have been studied in many different waters in the world. However, these effects on phytoplankton communities in coastal upwelling waters are still in need in various aspects such as specific responses of phytoplankton and its dynamics. Phytoplankton data of 15 stations in Ninh Thuan  - Binh Thuan coastal area collected in July 2016 (post El Niño year) and July 2017 (ENSO neutral year) was analyzed and comparing using diversity indices, composition and density of the phytoplankton to measure influences of ENSO on the phytoplankton community structure in coastal upwelling of South Centre Viet Nam. The results revealed significant differences of average species number, the Margalef, Shannon, and Simpson diversity indices and the density of phytoplankton between the two years. These values and indices were significant higher in ENSO neutral year (2017) than the post El Niño year (2016), except the Pielou evenness index. Phytoplankton community structures of two periods were different by 82.26% based on SIMPER analyzing.


2019 ◽  
Vol 10 (2) ◽  
pp. 60
Author(s):  
Nikita Kekenusa ◽  
Rose O.S.E Mantiri ◽  
Gaspar D Manu

This research was conducted at 3 stations in the seagrass ecosystem of the Tongkeina coastal waters district of Bunaken Darat Manado on March 16, 2019, at 10:35 - 13:45 WITA. This study aims to know the types and community structures of phytoplankton in the Tongkeina seagrass ecosystem and its environmental conditions. The method used to collect the sample is sampling. Samples were taken using a plankton net measuring 20 cm in mouth diameter with a mesh size of 60 microns. Based on the results of observations obtained by the composition of phytoplankton species, namely 17 genera of 22 species in 3 classes namely Bacillariophyceae, Cyanophyceae, and Pyramimonadophyceae. The highest density of phytoplankton in Tongkeina waters is at Station 2 (0.360 cells / l) with the highest relative density of Chaetoceros sp. (19.10%). While the highest density of phytoplankton is found at Station 3 (0.516 cells / l) with the highest relative density of Melosira sp. (21.69%). The lowest Diversity Index at Station 2 (H '= 2,217) and the highest at station 3 (H' = 2,284). This shows that overall these waters have moderate diversity values. The lowest Uniformity Index at Station 1 (e = 0.858) and the highest at Station 2 (e = 0.924). This shows that overall these waters have a medium uniformity value. The lowest dominance index at Station 3 (C = 0.119) and the highest at Station 1 (C = 0.127). This shows that no species dominate the waters. The water conditions such as temperature, salinity, pH, and brightness still support the growth of phytoplankton.Keywords: phytoplankton, community structure, seagrass, Tongkeina ABSTRAKPenelitian ini dilakukan pada 3 stasiun di  perairan ekosistem lamun kelurahan  Tongkeina kecamatan Bunaken Darat pada tanggal 16 Maret 2019 pukul 10:35 – 13:45 WITA, dengan tujuan mengetahui jenis dan struktur komunitas fitoplankton yang ada di perairan ekosistem lamun  Tongkeina serta kondisi lingkungannya. Metode yang digunakan adalah Metode sampling. Sampel diambil dengan menggunakan plankton net berdiameter mulut berukuran 20 cm dengan mesh size 60 mikron. Berdasarkan hasil pengamatan diperoleh komposisi jenis fitoplankton  yakni 17 genus 22 spesies dalam 3 kelas yaitu Bacillariophyceae, Cyanophyceae, dan Pyramimonadophyceae.Kepadatan tertinggi fitoplankton di perairan Tongkeina terdapat pada Stasiun 2 (0.360 sel/l) dengan kepadatan relatif tertinggi Chaetoceros sp. (19.10%). Sedangkan  kepadatan fitoplankton tertinggi terdapat pada Stasiun 3 (0.516 sel/l) dengan kepadatan relatif tertinggi Melosira sp. (21.69%). Indeks Keanekaragaman terrendah pada Stasiun 2 (H’= 2.217) dan tertinggi pada stasiun 3 (H’= 2.284). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keanekaragaman sedang. Indeks Keseragaman terrendah pada Stasiun 1  (e= 0.858) dan tertinggi pada Stasiun 2  (e= 0.924). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keseragaman  sedang. Indeks Dominansi terrendah pada Stasiun 3 (C= 0.119) dan yang tertinggi pada Stasiun 1 (C= 0.127). Hal ini menunjukkan bahwa tidak ada jenis yang mendominasi perairan. Adapun kondisi perairannya seperti suhu, salinitas, pH dan kecerahan masih menunjang pertumbuhan fitoplankton.Kata Kunci :Fitoplankton, Struktur Komunitas, Lamun, Tongkeina,


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