Plankton and water chemistry in Lake Njupfatet before and after liming

1995 ◽  
Vol 52 (3) ◽  
pp. 551-565 ◽  
Author(s):  
Peter Blomqvist ◽  
Russell T. Bell ◽  
Hans Olofsson ◽  
Ulrika Stensdotter ◽  
Katarina Vrede
Keyword(s):  
Organic Carbon ◽  
Inorganic Nitrogen ◽  
Zooplankton Biomass ◽  
Phytoplankton Growth ◽  
Particulate Phosphorus ◽  
Total Biomass ◽  
Calanoid Copepods ◽  
Particulate Carbon ◽  
Particulate Nitrogen ◽  
Before And After

Moderately acidified Lake Njupfatet was studied during 2 consecutive years, before and after liming (calcite), and compared with corresponding data from six reference lakes. After liming, the concentration of total phosphorus in the lake water decreased by some 30% as did the concentrations of particulate carbon, particulate nitrogen, particulate phosphorus, and phytoplankton biomass. Because of significant increases of inorganic nitrogen and dissolved organic carbon, the concentrations of total nitrogen and total organic carbon remained unchanged after liming. Before liming, there was a close balance between phosphorus and nitrogen limitation of phytoplankton growth, but we conclude that after liming the reduced concentrations of phosphorus induced phosphorus limitation of phytoplankton growth. Liming changed the phytoplankton community structure, most importantly causing the complete loss of the dominant species before liming, the cyanophyte Merismopedia tenuissima. The decrease in total biomass of phytoplankton was not compensated for by a corresponding increase in other species. After liming total biomasses of bacterioplankton and protozoan zooplankton did not change, while total biomass of metazoan zooplankton increased; hence, total plankton community carbon remained unchanged. Phytoplankton, protozoan, and metazoan zooplankton diversity (Shannon index) did not change after liming. Zooplankton biomass remained heavily dominated by calanoid copepods, typical of acidified lakes.

Investigation of a nutrient-growth model using a continuous culture of natural phytoplankton

1978 ◽  
Vol 58 (4) ◽  
pp. 923-941 ◽  
Author(s):  
K. J. Jones ◽  
P. Tett ◽  
A. C. Wallis ◽  
B. J. B. Wood
Keyword(s):  
Growth Rate ◽  
Continuous Culture ◽  
Algal Growth ◽  
Nutrient Status ◽  
Inorganic Phosphorus ◽  
Particulate Phosphorus ◽  
Particulate Carbon ◽  
Particulate Nitrogen ◽  
Rate Of Increase ◽  
Dominance Pattern

Phytoplankton from Loch Creran, Argyll was maintained in continuous culture for 41 days. During most of this time the mixture of species retained the diversity and dominance pattern typical of summer phytoplankton in the loch, notwithstanding the manipulation of algal nutrient status to bring about phosphorus control of growth. Results suggest that most detritus was washed out early in the experiment.The aim of the experiment was to test the applicability to natural multispecies phytoplankton of part of Droop's (1974, 1975) model of nutrient-limited algal growth. ‘Quasi-steady states’ with respect to concentration of chlorophyll, particulate carbon (PC), particulate phosphorus (PP) and particulate nitrogen (PN), wereobserved at two levels of input of dissolved inorganic phosphorus. At other times the algal phosphorus quota (estimated from the ratio of PP to PC) varied from about 0·002 to 0·015 atoms P per atom C. Specific growth rate was estimated from the rate of increase of PC. During part of the experiment, growth rate was linearly related to reciprocal phosphorus quota, thus confirming the applicability of the model.

scholarly journals Modelling carbon overconsumption and the formation of extracellular particulate organic carbon

2007 ◽  
Vol 4 (4) ◽  
pp. 433-454 ◽  
Author(s):  
M. Schartau ◽  
A. Engel ◽  
J. Schröter ◽  
S. Thoms ◽  
C. Völker ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Organic Nitrogen ◽  
Dissolved Inorganic Carbon ◽  
Inorganic Nitrogen ◽  
C:N Ratio ◽  
Algal Growth ◽  
Phytoplankton Growth ◽  
Maximum Likelihood Estimates ◽  
Model Parameters

Abstract. During phytoplankton growth a fraction of dissolved inorganic carbon (DIC) assimilated by phytoplankton is exuded in the form of dissolved organic carbon (DOC), which can be transformed into extracellular particulate organic carbon (POC). A major fraction of extracellular POC is associated with carbon of transparent exopolymer particles (TEP; carbon content = TEPC) that form from dissolved polysaccharides (PCHO). The exudation of PCHO is linked to an excessive uptake of DIC that is not directly quantifiable from utilisation of dissolved inorganic nitrogen (DIN), called carbon overconsumption. Given these conditions, the concept of assuming a constant stoichiometric carbon-to-nitrogen (C:N) ratio for estimating new production of POC from DIN uptake becomes inappropriate. Here, a model of carbon overconsumption is analysed, combining phytoplankton growth with TEPC formation. The model describes two modes of carbon overconsumption. The first mode is associated with DOC exudation during phytoplankton biomass accumulation. The second mode is decoupled from algal growth, but leads to a continuous rise in POC while particulate organic nitrogen (PON) remains constant. While including PCHO coagulation, the model goes beyond a purely physiological explanation of building up carbon rich particulate organic matter (POM). The model is validated against observations from a mesocosm study. Maximum likelihood estimates of model parameters, such as nitrogen- and carbon loss rates of phytoplankton, are determined. The optimisation yields results with higher rates for carbon exudation than for the loss of organic nitrogen. It also suggests that the PCHO fraction of exuded DOC was 63±20% during the mesocosm experiment. Optimal estimates are obtained for coagulation kernels for PCHO transformation into TEPC. Model state estimates are consistent with observations, where 30% of the POC increase was attributed to TEPC formation. The proposed model is of low complexity and is applicable for large-scale biogeochemical simulations.

scholarly journals Can microcystins affect zooplankton structure community in tropical eutrophic reservoirs?

2016 ◽  
Vol 76 (2) ◽  
pp. 450-460 ◽  
Author(s):  
T. A. S. V. Paes ◽  
I. A. S. Costa ◽  
A. P. C. Silva ◽  
E. M. Eskinazi-Sant’Anna
Keyword(s):  
Zooplankton Community ◽  
Population Level ◽  
Temporal Variations ◽  
Zooplankton Biomass ◽  
Total Biomass ◽  
Control Mechanisms ◽  
Calanoid Copepods ◽  
Negative Effects ◽  
Eutrophic Reservoirs ◽  
Allelopathic Compounds

Abstract The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcystins in water proved to be correlated with the cyanobacterial biovolume, indicating the contributions from colonial forms such as Microcystis in the production of cyanotoxins. At the community level, the total biomass of zooplankton was not correlated with the concentration of microcystin (r2 = 0.00; P > 0.001), but in a population-level analysis, the biomass of rotifers and cladocerans showed a weak positive correlation. Cyclopoid copepods, which are considered to be relatively inefficient in ingesting cyanobacteria, were negatively correlated (r2 = – 0.01; P > 0.01) with the concentration of cyanotoxins. Surprisingly, the biomass of calanoid copepods was positively correlated with the microcystin concentration (r2 = 0.44; P > 0.001). The results indicate that allelopathic control mechanisms (negative effects of microcystin on zooplankton biomass) do not seem to substantially affect the composition of mesozooplankton, which showed a constant and high biomass compared to the microzooplankton (rotifers). These results may be important to better understand the trophic interactions between zooplankton and cyanobacteria and the potential effects of allelopathic compounds on zooplankton.

A Proposed Method Suitable for Large-Scale Surveys of Biomass in Lakes

1974 ◽  
Vol 31 (3) ◽  
pp. 327-328
Author(s):  
George F. Carpenter
Keyword(s):  
Large Scale ◽  
Dry Weight ◽  
Zooplankton Biomass ◽  
Total Biomass ◽  
Particulate Carbon ◽  
Carbon And Nitrogen ◽  
Plankton Biomass ◽  
Total Phytoplankton ◽  
Filter Papers

A method for studying plankton biomass by comparing the results between planktonnet hauls and an integrated water column sample is described. Filtering the planktonnet sample through glass-fiber filter papers would yield planktonnet phytoplankton plus zooplankton biomass. Filtering the integrator sample would yield total phytoplankton biomass. Sieving part of this sample would give direct estimates of net and nannophytoplankton which could be used in combination with the values of net plankton biomass to give estimates of total biomass and zooplankton biomass.Ash-free dry weight is recommended instead of dry weight biomass. The results are easy to produce, are comparable with other parameters such as particulate carbon and nitrogen, and are in units which may be used in the determination of trophic status or nutrient budgets for a lake.

scholarly journals Modelling carbon overconsumption and the formation of extracellular particulate organic carbon

2007 ◽  
Vol 4 (1) ◽  
pp. 13-67 ◽  
Author(s):  
M. Schartau ◽  
A. Engel ◽  
J. Schröter ◽  
S. Thoms ◽  
C. Völker ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Organic Nitrogen ◽  
Dissolved Inorganic Carbon ◽  
Inorganic Nitrogen ◽  
C:N Ratio ◽  
Algal Growth ◽  
Phytoplankton Growth ◽  
Maximum Likelihood Estimates ◽  
Model Parameters

Abstract. During phytoplankton growth a fraction of dissolved inorganic carbon (DIC) assimilated by phytoplankton is exuded in the form of dissolved organic carbon (DOC), which can be transformed into extracellular particulate organic carbon (POC). A major fraction of extracellular POC is associated with carbon of transparent exopolymer particles (TEP; carbon content = TEPC) that form from dissolved polysaccharides (PCHO). The exudation of PCHO is linked to an excessive uptake of DIC that is not directly quantifiable from utilisation of dissolved inorganic nitrogen (DIN), called carbon overconsumption. Given these conditions, the concept of assuming a constant stoichiometric carbon-to-nitrogen (C:N) ratio for estimating new production of POC from DIN uptake becomes inappropriate. Here, a model of carbon overconsumption is analysed, combining phytoplankton growth with TEPC formation. The model describes two modes of carbon overconsumption. The first mode is associated with DOC exudation during phytoplankton biomass accumulation. The second mode is decoupled from algal growth, but leads to a continuous rise in POC while particulate organic nitrogen (PON) remains constant. While including PCHO coagulation, the model goes beyond a purely physiological explanation of building up carbon rich particulate organic matter (POM). The model is validated against observations from a mesocosm study. Maximum likelihood estimates of model parameters, such as nitrogen- and carbon loss rates of phytoplankton, are determined. The optimisation yields results with higher rates for carbon exudation than for the loss of organic nitrogen. It also suggests that the PCHO fraction of exuded DOC was 63±20% during the mesocosm experiment. Optimal estimates are obtained for coagulation kernels for PCHO transformation into TEPC. Model state estimates are consistent with observations, where 30% of the POC increase was attributed to TEPC formation. The proposed model is of low complexity and is applicable for large-scale biogeochemical simulations.

scholarly journals Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen

2012 ◽  
Vol 26 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. P. Wickland ◽  
G. R. Aiken ◽  
K. Butler ◽  
M. M. Dornblaser ◽  
R. G. M. Spencer ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Inorganic Nitrogen ◽  
Yukon River

Bacterioplankton, Phytoplankton, and Zooplankton Communities in a British Columbia Coastal Lake Before and After Nutrient Reduction

1986 ◽  
Vol 43 (8) ◽  
pp. 1504-1514 ◽  
Author(s):  
F. Joan Hardy ◽  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Growing Season ◽  
Nutrient Reduction ◽  
Nitrogen And Phosphorus ◽  
Coastal Lake ◽  
Before And After ◽  
High Concentrations

Inorganic nitrogen and phosphorus were applied weekly during the growing season from 1980 to 1982 and twice weekly in 1983 to Hobiton Lake, a warm monomictic coastal lake in British Columbia. The lake was not fertilized in 1984. Average numbers of bacteria during the growing season decreased from a high of 1.53 × 106∙mL−1 in the fertilized condition to 0.84 × 106∙mL−1 in the unfertilized condition. Chlorophyll a concentrations decreased from a maximum seasonal average of 2.69 μg∙L−1 (1981) to 1.30 μg∙L−1 (1984), and algal numbers decreased from 5.83 × 104∙mL−1 (1983) to 2.29 × 104∙mL−1 (1984). Although the numbers of phytoplankton in each size fraction (picoplankton, nanoplankton, or microplankton) decreased in the unfertilized condition, the greatest change was an almost fourfold decrease in picoplankton, which consisted of 90% cyanobacteria (primarily Synechococcus spp.). Abundance of the large diatoms Rhizosolenia spp. and Melosira spp. increased in 1984, resulting in an increase in average seasonal algal volume. Average densities of medium (0.15–0.84 mm) and large (0.85–1.5 mm) zooplankton were greatest in 1982, while rotifers and small zooplankton (0.10–0.14 mm) were most dense in 1984 following nutrient reduction. The lake had relatively high concentrations of planktivorous juvenile sockeye salmon (Oncorhynchus nerka) that appeared to minimize any direct effect of nutrient additions on zooplankton densities.

scholarly journals Forest defoliator outbreaks alter nutrient cycling in northern waters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Samuel G. Woodman ◽  
Sacha Khoury ◽  
Ronald E. Fournier ◽  
Erik J. S. Emilson ◽  
John M. Gunn ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Water Chemistry ◽  
Inorganic Nitrogen ◽  
Biogeochemical Cycles ◽  
Dissolved Inorganic Nitrogen ◽  
Insect Outbreaks ◽  
Receiving Waters ◽  
North Temperate Lakes ◽  
Lake Waters ◽  
Terrestrial Biomass

AbstractInsect defoliators alter biogeochemical cycles from land into receiving waters by consuming terrestrial biomass and releasing biolabile frass. Here, we related insect outbreaks to water chemistry across 12 boreal lake catchments over 32-years. We report, on average, 27% lower dissolved organic carbon (DOC) and 112% higher dissolved inorganic nitrogen (DIN) concentrations in lake waters when defoliators covered entire catchments and reduced leaf area. DOC reductions reached 32% when deciduous stands dominated. Within-year changes in DOC from insect outbreaks exceeded 86% of between-year trends across a larger dataset of 266 boreal and north temperate lakes from 1990 to 2016. Similarly, within-year increases in DIN from insect outbreaks exceeded local, between-year changes in DIN by 12-times, on average. As insect defoliator outbreaks occur at least every 5 years across a wider 439,661 km2 boreal ecozone of Ontario, we suggest they are an underappreciated driver of biogeochemical cycles in forest catchments of this region.

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