Preferred Language
Articles
/
Nhb9T4cBVTCNdQwCL0Tz
The dynamics of nutrient, toxic phytoplankton, nontoxic phytoplankton and zooplankton model
...Show More Authors

<p>The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability conditions of all possible equilibrium points are established. The occurrence of local bifurcation and Hopf bifurcation are investigated. Finally, numerical simulation is used to study the global dynamics of this model.</p>

Crossref
View Publication
Publication Date
Sat Jun 01 2024
Journal Name
Results In Engineering
Stability analysis for the phytoplankton-zooplankton model with depletion of dissolved oxygen and strong Allee effects
...Show More Authors

View Publication Preview PDF
Scopus (12)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Al-nahrain University-science
Global Stability of Harmful Phytoplankton and Herbivorous Zooplankton with Holling Type IV Functional Response
...Show More Authors

In this paper harmful phytoplankton and herbivorous zooplankton model with Hollimg type IV functional response is proposed and analyzed. The local stability analysis of the system is carried out. The global dynamics of the system is investigated with the help of the Lyapunov function. Finally, the analytical obtained results are supported with numerical simulation.

View Publication Preview PDF
Crossref
Publication Date
Sun Jun 01 2008
Journal Name
Baghdad Science Journal
Laboratory study on the effects of nutrient enrichment on a phytoplankton population in Sawa Lake, Iraq
...Show More Authors

Nutrient enrichment of Sawa lake water was made using different nitrogen and phosphorus concentrations during autumn and spring at three stations. Different concentrations of nitrogen, phosphorus and N: P ratios were used to test variations in phytoplankton population dynamics. Nitrogen at a concentration of 25 µmole.l-1 and N: P ratio of 10:1 gave highest phytoplankton cell number at all stations and seasons. A total of 64 algal taxa dominated by Bacillariophyceae followed by Cyanophyceae and Chlorophyceae were identified. The values of Shannon index of diversity were more than one in the studied stations.

View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Communications In Mathematical Biology And Neuroscience
The impact of fear and harvesting on plankton-fish system dynamics incorporating harmful phytoplankton in the contaminated environment
...Show More Authors

View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Sun Mar 03 2013
Journal Name
Baghdad Science Journal
Phytoplankton compositions in Alaaras torist Island Lake – Iraq
...Show More Authors

The study includes the phytoplankton compositions in Alaaras Lake , in summer 2008 and winter , spring , summer 2009. Samples were collected from three selected sites at north , middle and south of lake. A total of 74 taxa of phytoplankton were identified . The diatoms were the dominated by 44 taxa represented 82.8% of the total indentified species, followed by green algae ( Chlorophyta ) of 20 taxa (8.5%), and blue green algae (Cyanophyta of 7 taxa (7.2%). Tow species were recorded of Pyrrophyta and one species of Euglenophyta .The seasonal variation for Diatoms density showed tow peaks during Autumn and summer. Few species were dominated during the most studied period such as Cocconeis placentula var. euglypta, Synedra fasciculata and

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 13 2011
Journal Name
Baghdad Science Journal
Phytoplankton primary production in southern Iraqi marshes after restoration
...Show More Authors

Primary productivity and chlorophyll-a were used in this study to monitor the restoration process of southern Iraqi marshes (Al-Hewaizeh, central marshes, and Al-Hammar). The phytoplankton primary productivity was based on oxygen light/dark bottle method. Two different depths samples were taken monthly from six studied marshes stations (two stations for each marsh) during November 2005 to October 2006, while chlorophyll-a samples taken from surface water. The phytoplankton primary productivity values ranged 9.38 – 249.79 mg C/m3.hr for all marshes, its values for surface water sample ranged 11.71 – 256.24 mg C/m3.hr, while for 1m depth ranged 9.38 – 142.5 mg C/m3.hr. Chlorophyll-a values ranged between (1.1 – 21.26) µg/l indicating

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
The effect of wastewater disposal on the water quality and phytoplankton in Erbil wastewater channel.
...Show More Authors

In this study, phytoplankton density, chlorophyll-a, and selected physico- chemical parameters were investigated in Erbil wastewater channel. The surveys were carried out monthly from May 2003 to April 2004. Samplings were established on three sites from headwaters to the mouth. The results showed that pH was in alkaline side of neutrality, with significant differences (P<0.05) between sites 1 and 3. TSS concentration decreased from site 1 toward site 2 (mean value, 80.15 to 25.79 mg.l-1). A clear gradual increase in mineral content (TDS) observed from site one of the channel towards the mouthpart. Soluble reactive phosphate has a concentration maximum mean value reached 48.4 µg.l-1 which is recorded in site 2. A high positive relat

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 01 2023
Journal Name
Egyptian Journal Of Aquatic Biology And Fisheries
Environmental factors drive phytoplankton primary productivity in a shallow Lake
...Show More Authors

View Publication
Scopus (6)
Scopus Crossref
Publication Date
Thu Aug 01 2024
Journal Name
Egyptian Journal Of Aquatic Biology And Fisheries
Climate Changes and Their Impact on Phytoplankton and Physicochemical Properties of the Tigris River, Baghdad, Iraq
...Show More Authors

The study was conducted in the Tigris River in Baghdad during May 2021 until March 2022 to follow the impact of climate change, rising temperatures, and the presence of pollutants on the dynamics of phytoplankton and some physicochemical variables from four sites. The results showed that the climatic conditions during different seasons, in addition to the nature of the sampling sites, have a clear and significant impact on the studied traits and, in turn, affect the phytoplankton community. The highest average temperature (30.67 ˚C) was recorded; the pH values ranged between 8.70 & 6.75; the electrical conductivity (1208.18-770.11 µS/cm ) and the total dissolved solids (TDS) (778.95- 439.49 mg/L) were evaluated. Upon measuring

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Thu Apr 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Phytoplankton community within Al-Auda marsh in maysan province southern Iraq
...Show More Authors
Abstract<p>Phytoplankton assemblage in relation to physical and chemical characteristics of water in Al-Auda marsh of Maysan province southern Iraq was assessed from November 2012 to July 2013. Six sampling sites were chosen to examine all phytoplankton species in the study area. A total of 246 species and seventy-five genera have been recognized belonging to twelve phytoplankton classes as follows: Bacillariophyceae (106 taxa), Chlorophyceae (34 taxa), Euglenophyceae (29 taxa), Cyanophyceae (29 taxa), Conjugatophyceae (19 taxa), Mediophyceae (10 taxa), Cryptophyceas (5 taxa), Coscinodiscophyceae (4 taxa), Chrysophyceae (4 taxa), Dinophyceae (3 taxa), Trebouxiophyceae (2 taxa) whereas Compsopogonophyceae record</p> ... Show More
View Publication
Scopus (4)
Crossref (1)
Scopus Crossref