Picophytoplankton Seasonal Dynamics and Interactions with Environmental Variables in Three Mediterranean Coastal Lagoons

Methanogenesis may represent a key process in the terminal phases of anaerobic organic matter mineralization in sediments of coastal lagoons. The aim of the present work was to study the temporal and spatial dynamics of methanogenic archaea in sediments of tropical coastal lagoons and their relationship with environmental changes in order to determine how these influence methanogenic community. Sediment samples were collected during the dry (February, May, and early June) and rainy seasons (July, October, and November). Microbiological analysis included the quantification of viable methanogenic archaea (MA) with three substrates and the evaluation of kinetic activity from acetate in the presence and absence of sulfate. The environmental variables assessed were temperature, pH, Eh, salinity, sulfate, solids content, organic carbon, and carbohydrates. MA abundance was significantly higher in the rainy season (106–107 cells/g) compared with the dry season (104–106 cells/g), with methanol as an important substrate. At spatial level, MA were detected in the two layers analyzed, and no important variations were observed either in MA abundance or activity. Salinity, sulfate, solids, organic carbon, and Eh were the environmental variables related to methanogenic community. A conceptual model is proposed to explain the dynamics of the MA.

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Seasonal dynamics of Bythonomus lemani and Bothrioneurum vejdovskyanum (Oligochaeta, Annelida) in relation to environmental variables

Biologia ◽

10.2478/s11756-006-0085-x ◽

2006 ◽

Vol 61 (5) ◽

Cited By ~ 3

Author(s):

Jana Schenková ◽

Jan Helešic ◽

Jiří Jarkovský

Keyword(s):

Seasonal Dynamics ◽

Environmental Variables ◽

Habitat Preferences ◽

Oxygen Demand ◽

Significant Negative Correlation ◽

Life Cycles ◽

Reproduction Cycle ◽

Influence Of Water ◽

One Year ◽

First Time

AbstractThe seasonal dynamics of Bythonomus lemani (Lumbriculidae) were studied for the first time and the knowledge of Bothrioneurum vejdovskyanum (Tubificidae) was extended based on four quantitative samples of oligochaetes taken monthly in the Rokytná River (Czech Republic) during a two-year study (April 1999–April 2001). The influence of water temperature, velocity, depth, discharge, pH, conductivity, dissolved oxygen amount and biochemical oxygen demand (BOD) on their life cycles was evaluated. Habitat preferences of the juvenile and adult stages were recorded. Time series analysis was used to determine the worm densities, seasonality and trends. For Byth. lemani one distinct reproduction cycle per year was found and this was regulated by temperature, while Both. vejdovskyanum showed a one-year cycle not significantly dependent on measured environmental variables. The overall trend was an increase in density for Byth. lemani and a decrease in density for Both. vejdovskyanum. Byth. lemani showed a significant negative correlation between the trend of its density and BOD concentration.

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Diatom Assemblages From Surface Sediments of Two Coastal Lagoons, the Central Part of the Red Sea, Saudi Arabia and Their Associated Environmental Variables

Thalassas An International Journal of Marine Sciences ◽

10.1007/s41208-020-00283-z ◽

2021 ◽

Author(s):

Abdelfattah A. Zalat ◽

Mostafa M. El-Sheekh ◽

Ibrahim M. Ghandour ◽

Ali S. Basaham

Keyword(s):

Saudi Arabia ◽

Red Sea ◽

Environmental Variables ◽

Surface Sediments ◽

Coastal Lagoons ◽

Diatom Assemblages

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Seasonal variations of phytoplankton size structure in relation to environmental variables in three Mediterranean shallow coastal lagoons

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2018.07.002 ◽

2018 ◽

Vol 212 ◽

pp. 95-104 ◽

Cited By ~ 8

Author(s):

Silvia Pulina ◽

Cecilia Teodora Satta ◽

Bachisio Mario Padedda ◽

Nicola Sechi ◽

Antonella Lugliè

Keyword(s):

Seasonal Variations ◽

Environmental Variables ◽

Size Structure ◽

Coastal Lagoons ◽

Phytoplankton Size ◽

Phytoplankton Size Structure

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Do interrelationships among benthic components mirror disturbance levels?

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315411001251 ◽

2011 ◽

Vol 92 (2) ◽

pp. 235-243

Author(s):

P. Malea ◽

T. Kevrekidis ◽

N. Papageorgiou ◽

A. Mogias ◽

C. Arvanitidis

Keyword(s):

Multidimensional Scaling ◽

Environmental Stress ◽

Functional Groups ◽

Environmental Variables ◽

Coastal Lagoons ◽

Demersal Fish ◽

Biological Organization ◽

Second Stage ◽

Metric Multidimensional Scaling ◽

Disturbance Gradient

The hypothesis tested in this study is that changes in benthic ecosystem components interrelationships may mirror the degree of environmental stress in the Mediterranean coastal lagoons. Multivariate matrices deriving from four benthic components (macrophytes, zoobenthos, epibenthic decapods and demersal fish) from four lagoonal stations along a well-defined disturbance gradient were compared by means of second-stage non-metric multidimensional scaling (MDS). The resulting inter-matrix distances were used as a proxy for the identification of the degree of disturbance. The approach followed is novel in that it uses information from higher levels of the biological organization by taking into account more than a single benthic component, thus representing broad categories of functional groups. The second-stage MDS plots depict differences between inter-component distances in the sampling stations according to the degree of disturbance they experience and the BIOENV analysis demonstrates that certain components are correlated with the environmental variables at a higher degree in the most disturbed stations.

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