scholarly journals RELACIONES CONTEMPORANEAS Y REZAGADAS ENTRE VARIABLES FISICOQUIMICAS Y BIOLOGICAS EN LA CIENAGA GRANDE DE SANTA MARTA, CARIBE COLOMBIANO

2016 ◽  
Vol 27 ◽  
Author(s):  
Sven Zea ◽  
Ramón Giraido H. ◽  
José Ernesto Mancera P ◽  
Jorge Martínez C.
Keyword(s):  
Primary Production ◽  
Total Nitrogen ◽  
Phytoplankton Biomass ◽  
Apparent Lack ◽  
Biological Variables ◽  
Physical Chemical ◽  
Generation Times ◽  
Mean And Variance ◽  
Cross Correlations ◽  
Time Lagged

From available data from four sampling stations at Ciénaga Grande de Santa Marta coastal lagoon (Colombian Caribbean), contemporary and time-lagged cross-correlations between biweekly series of "biological" variables (chrolophyll a, primary productivity) and "physical-chemical" variables (salinity, transparency, inorganic nutrientes, total nitrogen and phosphorous, phaeopigments, seston proteins) were explored. In contrast with the original analyses, turning series stationary (constant mean and variance) eliminated variations in trend and magnitude associated with climate, and emphasized variation at the scale of weeks. As a result, changes in primary production were not related either with contemporary changes in phytoplankton biomass (measured as chlorophyll a) or with previous or contemporary changes in physical chemical variables. This apparent lack of effect of the inorganic nutrients regime on the primary production may occur because nutrient availability is the dinamyc result of uptake and recycling. Only, increases in total nitrogen were associated with rises in primary production 4 weeks later, possibly from lagged used of reserves by phytoplankton. Variations in phytoplankton biomass were positively correlated with contemporary changes in dissolved phosphorous, and negatively with changes in transparency. The first relation could be caused by phosphorous liberation from the benthos in nocturnal anoxic conditions during massive blooms. The second may occur because the main agent conditioning water transparency is phytoplankton. In contrast, increases in primary production were followed by decreases in dissolved nitrogen and phosphorous two weeks later, again possibly in relation to phytoplankton generation times and the dynamics of uptake and recycling.

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

scholarly journals Effects of Weir Construction on Phytoplankton Assemblages and Water Quality in a Large River System

2018 ◽  
Vol 15 (11) ◽  
pp. 2348 ◽  
Author(s):  
Hae-Jin Lee ◽  
Hae-Kyung Park ◽  
Se-Uk Cheon
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
River System ◽  
Large River ◽  
Anthropogenic Factors ◽  
Centric Diatom ◽  
Nakdong River ◽  
Biological Variables ◽  
Physical Chemical ◽  
The Nakdong River

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006–2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.

scholarly journals The response of Carlos Botelho (Lobo, Broa) reservoir to the passage of cold fronts as reflected by physical, chemical, and biological variables

2004 ◽  
Vol 64 (1) ◽  
pp. 177-186 ◽  
Author(s):  
J. G. Tundisi ◽  
T. Matsumura-Tundisi ◽  
J. D. Arantes Junior ◽  
J. E. M. Tundisi ◽  
N. F. Manzini ◽  
...  
Keyword(s):  
Management Strategies ◽  
Vertical Mixing ◽  
Continuous System ◽  
Cyanobacterial Blooms ◽  
Metropolitan Region ◽  
Climatological Data ◽  
Cold Fronts ◽  
Biological Variables ◽  
Physical Chemical ◽  
Shallow Reservoirs

This paper describes and discusses the impacts of the passage of cold fronts on the vertical structure of the Carlos Botelho (Lobo-Broa) Reservoir as demonstrated by changes in physical, chemical, and biological variables. The data were obtained with a continuous system measuring 9 variables in vertical profiles in the deepest point of the reservoir (12 m) coupled with climatological information and satellite images, during a 32-day period in July and August, 2003. During periods of incidence of cold fronts the reservoir presented vertical mixing. After the dissipation of the cold fronts a period of stability followed with thermal, chemical, and biological (chlorophyll-a) stratification. Climatological data obtained during the cold front passage showed lower air temperature, higher wind speed and lower solar radiation. The response of this reservoir can exemplify a generalized process in all shallow reservoirs in the Southeast Brazil and could have several implications for management, particularly in relation to the phytoplankton population dynamics and development of cyanobacterial blooms. Using this as a basis, a predictive model will be developed with the aim of advancing management strategies specially for the drinking water reservoirs of the Metropolitan Region of São Paulo.

Bottom-up and top-down effects on phytoplankton functional groups in Hulun Lake, China

2021 ◽  
Vol 57 ◽  
pp. 3
Author(s):  
Chengxue Ma ◽  
Chang Zhao ◽  
Patteson Chula Mwagona ◽  
Ziyu Li ◽  
Zixuan Liu ◽  
...  
Keyword(s):  
Functional Groups ◽  
Phytoplankton Biomass ◽  
Eutrophic Lake ◽  
Positive Influence ◽  
Freshwater Ecosystems ◽  
Top Down ◽  
Bottom Up ◽  
Physical Chemical ◽  
Phytoplankton Functional Groups ◽  
Negative Effect

The debates about the extent to which phytoplankton in freshwater ecosystems are regulated by top-down or bottom-up forces have been ongoing for decades. This study examines the effects of bottom-up and top-down factors on the phytoplankton functional groups in a eutrophic lake. Phytoplankton and zooplankton were sampled and physical-chemical variables measured from May 2019 to October 2019 in Lake Hulun, China. Approximately 43 phytoplankton species were observed and grouped into 23 functional groups. For the zooplankton, about 27 species were observed and classified into 8 functional groups. The study revealed that the bottom-up effects of physical-chemical variables on some phytoplankton functional groups was stronger than the top-down effects of zooplankton. Water temperature (WT), total phosphorus (TP), total nitrogen (TN), conductivity (Cond), water transparency (SD), and dissolved oxygen (DO) significant influence the biomass of the phytoplankton functional groups. The biomass of phytoplankton functional groups was influenced positively by nutrient availability likely because nutrients influence the growth and reproduction of phytoplankton in freshwater. WT and DO had a positive influence on biomass of phytoplankton functional groups. Conversely, phytoplankton biomass revealed a decreasing trend when SD and Cond significantly increased. This study showed that zooplankton functional groups were positively correlated with phytoplankton biomass implying that the top-down control of phytoplankton by the zooplankton in the lake is not strong enough to produce a negative effect. It is evident that the zooplankton functional groups in Lake Hulun are controlled more by bottom-up force than top-down.

scholarly journals Seasonal patterns in phytoplankton biomass across the northern and deep Gulf of Mexico: a numerical model study

2018 ◽  
Vol 15 (11) ◽  
pp. 3561-3576 ◽  
Author(s):  
Fabian A. Gomez ◽  
Sang-Ki Lee ◽  
Yanyun Liu ◽  
Frank J. Hernandez Jr. ◽  
Frank E. Muller-Karger ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Primary Production ◽  
Phytoplankton Biomass ◽  
Mississippi Delta ◽  
Three Dimensional ◽  
Rate Of Change ◽  
Integrated Analysis ◽  
Biogeochemical Model ◽  
Seasonal Patterns ◽  
Biogeochemical Models

Abstract. Biogeochemical models that simulate realistic lower-trophic-level dynamics, including the representation of main phytoplankton and zooplankton functional groups, are valuable tools for improving our understanding of natural and anthropogenic disturbances in marine ecosystems. Previous three-dimensional biogeochemical modeling studies in the northern and deep Gulf of Mexico (GoM) have used only one phytoplankton and one zooplankton type. To advance our modeling capability of the GoM ecosystem and to investigate the dominant spatial and seasonal patterns of phytoplankton biomass, we configured a 13-component biogeochemical model that explicitly represents nanophytoplankton, diatoms, micro-, and mesozooplankton. Our model outputs compare reasonably well with observed patterns in chlorophyll, primary production, and nutrients over the Louisiana–Texas shelf and deep GoM region. Our model suggests silica limitation of diatom growth in the deep GoM during winter and near the Mississippi delta during spring. Model nanophytoplankton growth is weakly nutrient limited in the Mississippi delta year-round and strongly nutrient limited in the deep GoM during summer. Our examination of primary production and net phytoplankton growth from the model indicates that the biomass losses, mainly due to zooplankton grazing, play an important role in modulating the simulated seasonal biomass patterns of nanophytoplankton and diatoms. Our analysis further shows that the dominant physical process influencing the local rate of change of model phytoplankton is horizontal advection in the northern shelf and vertical mixing in the deep GoM. This study highlights the need for an integrated analysis of biologically and physically driven biomass fluxes to better understand phytoplankton biomass phenologies in the GoM.

The response of reservoirs of southeastern Brazil to the passage of cold fronts as reflected by physical, chemical and biological variables

2006 ◽  
Vol 29 (4) ◽  
pp. 2124-2128
Author(s):  
J.G. Tundisi ◽  
N.Y. Sebastien ◽  
T. Matsumura-Tundisi ◽  
J.E.M. Tundisi ◽  
N.F. Manzini
Keyword(s):  
Southeastern Brazil ◽  
Cold Fronts ◽  
Biological Variables ◽  
Physical Chemical

Relationships of Phytoplankton Biomass with Soluble Nutrients, Primary Production, and Chlorophyll a in Lake Erie, 1970

1976 ◽  
Vol 33 (3) ◽  
pp. 601-611 ◽  
Author(s):  
M. Munawar ◽  
N. M. Burns
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Lake Erie ◽  
Soluble Reactive Phosphorus ◽  
Distribution Patterns ◽  
Statistical Procedure ◽  
Annual Average ◽  
Average Distribution ◽  
Reactive Phosphorus

Comparison of the annual average distribution patterns of phytoplankton biomass, chlorophyll a, primary production, soluble reactive phosphorus, nitrate + nitrite, and ammonia concentrations revealed that these six variables had very similar distributions in Lake Erie during 1970. However, statistical analysis of the data only revealed a few consistent relationships between these variables. The phytoplankton biomass was correlated with chlorophyll a only in the summer and fall as was primary production with chlorophyll a and biomass. There was no correlation between these three variables during the spring. Also, there was no consistent relationship between biomass and soluble nutrients. The primary production and activity coefficient (mg Cassimilated per milligram phytoplankton biomass per day) were found to be unrelated to temperature. The statistical procedure of factor analysis showed that in the spring, primary production correlated with the phosphorus and nitrogen soluble nutrients only, whereas during summer, primary production correlated with biomass, chlorophyll a, the major plankton groups (Cyanophyta, Chlorophyta, Chrysomonadinae, and Diatomeae), and the phosphorus nutrients. In the fall, production was positively correlated with phytoplankton biomass and with the Chlorophyta in particular. The use of chlorophyll a and temperature as variables in the equation to estimate phytoplankton growth in Lake Erie was found to be questionable.

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