Response of a Phytoplankton Community to Controlled Partial Recovery from Experimental Acidification

1991 ◽  
Vol 48 (6) ◽  
pp. 1022-1029 ◽  
Author(s):  
D. L. Findlay ◽  
S. E. M. Kasian

Lake 223 was experimentally acidified with H2SO4 from 1976 to 1989. The pH was reduced from 6.7 (1974) to 5.0 (1981) and held there for 3 yr (1981–83). Beginning in 1984 the pH was allowed to increase at a controlled rate by reduction of acid additions, resulting in a two-step recovery of 4 yr at pH ~5.5 and 2 yr at pH ~5.8. During the first 6 yr of early recovery, species diversity of the phytoplankton community increased linearly with pH and the number of common species increased. Total phytoplankton biomass remained elevated above preacidification estimates or increased. Dinoflagellates and cyanophytes remained codominant with little evidence of other taxonomic groups increasing.

2017 ◽  
Vol 68 (6) ◽  
pp. 1061 ◽  
Author(s):  
Juliana dos Santos Severiano ◽  
Viviane Lúcia dos Santos Almeida-Melo ◽  
Enaide Marinho de Melo-Magalhães ◽  
Maria do Carmo Bittencourt-Oliveira ◽  
Ariadne do Nascimento Moura

Experiments were conducted to evaluate the N:P ratio, as well as the effects of the interaction between this ratio and zooplankton, on phytoplankton in a tropical reservoir. Three experiments were performed in the presence (+Z) or absence (–Z) of zooplankton and the addition of N and P in different ratios (N:P molar ratio of 5, 16 and 60).In Experiment I, the total phytoplankton biomass and biomass by taxonomic class and species of the N:P 16–Z treatment did not differ significantly from that of the control, whereas for N:P 16+Z, there was a reduction in total phytoplankton. In Experiment II, there was a significant increase in Bacillariophyceae and the biomass of two species in the N:P 60–Z treatment. For the N:P 60+Z treatment, a significant reduction was observed in the total phytoplankton biomass and the biomass of three phytoplankton classes and three species. In Experiment III, there was an increase in the biomass of Dinophyceae with the N:P 5–Z treatment. In the N:P 5+Z treatment, there was a significant reduction in total phytoplankton biomass and the biomass of the phytoplankton class and five species. The findings of the present study reveal that zooplankton species native to a tropical reservoir can change the structure of the phytoplankton community and the response of these organisms to variations in nutrients.


Author(s):  
Kirill K. Kivva ◽  
Tatiana V. Polyakova ◽  
Antonina V. Polyakova

The hydrochemical structure of the Caspian Sea, which is formed and changed under the influence of the dynamics of water and the intensity of production and destruction processes, has been studied. The formation of the biogenic base and hydrochemical structure of the waters of the Caspian Sea is greatly influenced by the phytoplankton community. The dominant species of Pseudosolenia calcar-avis and Prorocentrum cordatum, which constitute 60–95% of the population and more than 80% of the total phytoplankton biomass, are mainly responsible for the redistribution of chemical components in the sea.


1981 ◽  
Vol 38 (5) ◽  
pp. 524-534 ◽  
Author(s):  
Bruce D. LaZerte ◽  
Susan Watson

We tested the hypothesis that total phytoplankton biomass can predict phytoplankton community structure independent of its taxonomic composition. From a 2-yr study on Lake Memphremagog, Quebec, which exhibits a marked axial trophic gradient, 133 samples were rarefied to uniform count sizes and a range of diversity numbers, based on proportional biomass, was calculated for each. Biomass is a good predictor of evenness (0.7 < R < 0.9), but not species richness (0.1 < R < 0.3), and this prediction is independent of changes in taxonomic composition. Species richness is more directly related to season and changes in taxonomic composition.Key words: diversity, evenness, species richness, phytoplankton


2021 ◽  
Vol 12 ◽  
Author(s):  
Javier Alegria Zufia ◽  
Hanna Farnelid ◽  
Catherine Legrand

Picophytoplankton in the Baltic Sea includes the simplest unicellular cyanoprokaryotes (Synechococcus/Cyanobium) and photosynthetic picoeukaryotes (PPE). Picophytoplankton are thought to be a key component of the phytoplankton community, but their seasonal dynamics and relationships with nutrients and temperature are largely unknown. We monitored pico- and larger phytoplankton at a coastal site in Kalmar Sound (K-Station) weekly during 2018. Among the cyanoprokaryotes, phycoerythrin-rich picocyanobacteria (PE-rich) dominated in spring and summer while phycocyanin-rich picocyanobacteria (PC-rich) dominated during autumn. PE-rich and PC-rich abundances peaked during summer (1.1 × 105 and 2.0 × 105 cells mL–1) while PPE reached highest abundances in spring (1.1 × 105 cells mL–1). PPE was the main contributor to the total phytoplankton biomass (up to 73%). To assess nutrient limitation, bioassays with combinations of nitrogen (NO3 or NH4) and phosphorus additions were performed. PE-rich and PC-rich growth was mainly limited by nitrogen, with a preference for NH4 at &gt;15°C. The three groups had distinct seasonal dynamics and different temperature ranges: 10°C and 17–19°C for PE-rich, 13–16°C for PC-rich and 11–15°C for PPE. We conclude that picophytoplankton contribute significantly to the carbon cycle in the coastal Baltic Sea and underscore the importance of investigating populations to assess the consequences of the combination of high temperature and NH4 in a future climate.


2021 ◽  
Author(s):  
Javier Alegria Zufia ◽  
Hanna Farnelid ◽  
Catherine Legrand

Abstract Picophytoplankton in the Baltic Sea includes picocyanobacteria (Synechococcus/Cyanobium) and photosynthetic picoeukaryotes (PPE). Picophytoplankton are thought to be a key component of the phytoplankton community but their seasonal dynamics and relationships with nutrients and temperature are largely unknown. We monitored pico- and larger phytoplankton at a coastal site in Kalmar Sound (K-Station) weekly during 2018. Among the picocyanobacteria, phycoerythrin-rich Synechococcus (PE-rich) dominated in spring and summer while phycocyanin-rich Synechococcus (PC-rich) dominated during autumn. PE-rich and PC-rich abundances peaked during summer (1.1x105 and 2.0x105 cells mL− 1) while PPE reached highest abundances in spring (1.1x105 cells mL− 1). PPE was the main contributor to the total phytoplankton biomass (3–73%). To assess nutrient limitation, bioassays with combinations of nitrogen (NO3 or NH4) and phosphorus additions were performed. PE-rich and PC-rich growth was mainly limited by nitrogen, with a preference for NH4 at 15–19°C. The three groups had distinct seasonal dynamics and optimal temperatures for growth were 10°C and 17–19°C for PE-rich, 13–16°C for PC-rich and 11–15°C for PPE. We conclude that picophytoplankton contribute significantly to the carbon cycle in the coastal Baltic Sea and underscore the importance of investigating functional groups to assess the consequences of the combination of high temperature and NH4 in a future climate.


1992 ◽  
Vol 49 (12) ◽  
pp. 2605-2610 ◽  
Author(s):  
Susan Watson ◽  
Edward McCauley ◽  
John A. Downing

It has long been recognized that there is a positive relationship between total phytoplankton biomass and eutrophication. Recent independent studies demonstrated that algal biomass (chlorophyll) actually responds in a nonlinear, sigmoidal fashion with increasing phosphorus levels among lakes. Chlorophyll has been considered (by some authors) as an inconsistent estimate of algal biomass. Using a wide range of published data, we first demonstrate that the sigmoidal nature of the phosphorus–biomass relationship is quite robust, and not simply generated by a systematic variation in the relationship between algal chlorophyll to cell volume ratio and nutrient levels. We show that the sigmoid relationship with total phosphorus persists whether algal biomass is measured by chlorophyll or biovolume. We hypothesize that this nonlinearity actually reflects an underlying systematic variation in one or more of the components of total phytoplankton biomass. In this paper, we examine two functional size groups and show that the large inedible fraction exhibits a strong, nonlinear response to increasing nutrient levels, while the small edible algae do not vary systematically with phosphorus. We hypothesize that this discontinuous shift in the ratio of edible to inedible phytoplankton should be accompanied by concomitant shifts in the structure of the herbivore community.


2020 ◽  
Vol 37 ◽  
pp. 34-42
Author(s):  
Liudmila Stelmakh ◽  
Nela Kovrigina ◽  
Tatiana Gorbunova

Some ways of the Black Sea coastal waters phytoplankton community adaptation to changes in water temperature, nutrients concentration and anthropogenic pollution have been identified on the example of the Sevastopol Bay. The increase in water temperature and decrease in nutrient content in the studied waters during 2000 – 2014 caused a gradual decrease in the chlorophyll a concentrations, total phytoplankton biomass and its re-composition, predominantly in the summer and autumn periods. The phytoplankton restructuring was predominantly reflected by a decrease in relative diatoms contribution in the total phytoplankton biomass and an increase in dinoflagellates contribution. Among the dominant diatoms species, the share of resistant species to high temperatures, pollution, low nitrate content in the water and microzooplankton grazing was increasing. An increase in nitrate concentration in the studied waters in 2020 led to increase in total phytoplankton biomass and a predominance of diatoms species, which under the stated conditions did not lead to bloom emergence as were regularly observed earlier in the Sevastopol region.


2015 ◽  
Vol 46 (3) ◽  
pp. 403-422
Author(s):  
Józefa Sosnowska

Species composition of phytoplankton, its biomass, share of nannoplankton, and concentration of chlorophyll and pheophytin in phytoplankton and nannoplankton were assessed basing on the materials collected from two pelagic stations of Lakę Żarnowieckie during the period 30 March - 6 December 1974. Average and maximal values of phytoplankton biomass (4-5 and 10-11 mg/1 respectively), as well as the concentration of chlorophyll (1.7 -10.0 μg/l together with pheophytin) point to slightly advanced eutrophication of the lake. Share of nannoplankton in total phytoplankton biomass was very low (as a rule below 3%) with an increase to 15% only in spring. Relatively slight taxonomic differentiation of phytoplankton (164 taxons), its qualitative composition with the predominance of <i>Cyanophyceae</i> in summer, and of <i>Bacillariophyceae</i> in spring and autumn, as also seasonal succession of algae, point to eutrophic character of the lake.


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