scholarly journals Mathematical analysis of plankton population dynamics

2020 ◽  
Vol 16 (1) ◽  
pp. 109-114
Author(s):  
Fatin Nadiah Yussof ◽  
Normah Maan ◽  
Nadzri Reba
Keyword(s):  
Mathematical Model ◽  
Population Dynamics ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Health Effect ◽  
Economic Loss ◽  
Toxic Chemicals ◽  
Toxic Phytoplankton ◽  
Interior Equilibrium ◽  
Plankton Population

Harmful algal blooms (HABs) event that causes enormous economic loss and health effect raises concerns among environmentalists. In this paper, a mathematical model of interaction between nutrient, toxin-producing phytoplankton (TPP), non-toxic phytoplankton (NTP), zooplankton, and toxic chemicals is proposed to study on how the process of these HABs occurred. The model of interaction is represented by Ordinary Differential Equations (ODEs) and stability analysis of the model is conducted. Several conditions for the system to be stable around trivial and interior equilibrium point are obtained. From the analysis, it is observed that under nutrient limitation, the amounts of toxic chemicals secreted out by the TPP are increased. As a result, NTP population and zooplankton population are affected by the situation. If this situation is prolonged, this will result in the extinction of both populations. Overall, this study shows that TPP release more toxic chemicals when the nutrient is limited and gives a better understanding on the occurrence of HABs event. 

Study on the Selective Grazing of Zooplankton in Plankton Ecosystem

2013 ◽  
Vol 864-867 ◽  
pp. 17-21
Author(s):  
Yan Lin Zheng ◽  
Zhuo Ying Lv
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Marine Ecosystem ◽  
Laboratory Data ◽  
Ecosystem Dynamics ◽  
Human Environment ◽  
Grazing Behavior ◽  
Toxic Phytoplankton ◽  
Type Iv ◽  
Selective Grazing

Harmful algal blooms (Habs) caused great harm to the human environment. Habs occurrence was connected with other types of plankton. This relationship may be restrictive, and may also be promotional. Selectivity of zooplankton grazing has an important influence on the Habs. The behavior of zooplankton selective grazing was studied in the plankton ecosystem formed by three populations of nontoxic phytoplankton-toxic phytoplankton-zooplankton (NTP-TTP-Z) system. The selective grazing function of zooplankton on toxic phytoplankton and non-toxic phytoplankton was built based on Holling type IV functional response. Numerical simulation was given depending on the laboratory data. Results show that the models nicely explained the selective grazing behavior of zooplankton in the three species ecosystem, and provided key parameters for the marine ecosystem dynamics models.

scholarly journals A Novel Cyclophilin B Gene in the Red Tide DinoflagellateCochlodinium polykrikoides: Molecular Characterizations and Transcriptional Responses to Environmental Stresses

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sofia Abassi ◽  
Hui Wang ◽  
Bum Soo Park ◽  
Jong-Woo Park ◽  
Jang-Seu Ki
Keyword(s):  
Stress Responses ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Economic Loss ◽  
Cell Physiology ◽  
Transcriptional Responses ◽  
Splice Leader ◽  
Cyclophilin B ◽  
Cell Counts

The marine dinoflagellateCochlodinium polykrikoidesis one of the most common ichthyotoxic species that causes harmful algal blooms (HABs), which leads to ecological damage and huge economic loss in aquaculture industries. Cyclophilins (CYPs) belong to the immunophilin superfamily, and they may play a role in the survival mechanisms of the dinoflagellate in stress environments. In the present study, we identified a novel cyclophilin gene fromC. polykrikoidesand examined physiological and gene transcriptional responses to biocides copper sulphate (CuSO4) and sodium hypochlorite (NaOCl). The full length ofCpCYPwas 903 bp, ranging from the dinoflagellate splice leader (DinoSL) sequence to the polyA tail, comprising a 639 bp ORF, a 117 bp 5′-UTR, and a 147 bp 3′-UTR. Motif and phylogenetic comparisons showed that CpCYP was affiliated to group B of CYP. In biocide stressors, cell counts, chlorophylla, and photosynthetic efficiency (Fv/Fm) ofC. polykrikoideswere considerably decreased in both exposure time- and dose-dependent manners. In addition,CpCYPgene expression was significantly induced after 24 h exposure to the biocide-treated stress conditions. These results indicate an effect of the biocides on the cell physiology and expression profile ofCpCYP, suggesting that the gene may play a role in environmental stress responses.

Population dynamics of potentially harmful algal blooms in Bizerte Lagoon, Tunisia

2014 ◽  
Vol 39 (2) ◽  
pp. 177-188 ◽  
Author(s):  
D Bouchouicha Smida ◽  
I Sahraoui ◽  
B Grami ◽  
H Hadj Mabrouk ◽  
A Sakka Hlaili
Keyword(s):  
Population Dynamics ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Bizerte Lagoon

scholarly journals Depth-Dependent Spatiotemporal Dynamics of Overwintering Pelagic Microcystis in a Temperate Water Body

2021 ◽  
Vol 9 (8) ◽  
pp. 1718
Author(s):  
Haolun Tian ◽  
Junjie Jin ◽  
Bojian Chen ◽  
Daniel D. Lefebvre ◽  
Stephen C. Lougheed ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Water Body ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Temperate Water ◽  
Near Surface ◽  
Adverse Conditions ◽  
Lake Bottom ◽  
Ecological Success

Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic–benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and suggest that sediment serves as the major inoculum for subsequent summer blooms. However, the contemporaneous overwintering pelagic population may be important as well but is understudied. In this study, we investigated near-surface and near-bottom pelagic population dynamics of both microcystin-producing Microcystis and total Microcystis over six weeks in winter at Dog Lake (South Frontenac, ON, Canada). We quantified relative Microcystis concentrations using real-time PCR. Our results showed that the spatiotemporal distribution of overwintering pelagic Microcystis was depth dependent. The abundance of near-bottom pelagic Microcystis declined with increased depth with no influence of depth on near-surface Microcystis abundance. In the shallow region of the lake (<10 m), most pelagic Microcystis was found near the lake bottom (>90%). However, the proportion of near-surface Microcystis rose sharply to over 60% as the depth increased to approximately 18 m. The depth-dependent distribution pattern was found to be similar in both microcystin-producing Microcystis and total Microcystis. Our results suggest the top of the water column may be a more significant contributor of Microcystis recruitment inoculum than previously thought and merits more attention in early CHAB characterization and remediation.

scholarly journals Physical flow effects can dictate plankton population dynamics

2019 ◽  
Vol 16 (157) ◽  
pp. 20190247 ◽  
Author(s):  
J. R. Woodward ◽  
J. W. Pitchford ◽  
M. A. Bees
Keyword(s):  
Population Dynamics ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Mean Field ◽  
Economic Consequences ◽  
Mean Flow ◽  
Inertia Effects ◽  
Physical Forcing

Oceanic flows do not necessarily mix planktonic species. Differences in individual organisms’ physical and hydrodynamic properties can cause changes in drift normal to the mean flow, leading to segregation between species. This physically driven heterogeneity may have important consequences at the scale of population dynamics. Here, we describe how one form of physical forcing, circulating flows with different inertia effects between phytoplankton and zooplankton, can dramatically alter excitable plankton bloom dynamics. This may impact our understanding of the initiation and development of harmful algal blooms (HABs), which have significant negative ecological and socio-economic consequences. We study this system in detail, providing spatio-temporal dynamics for particular scenarios and summarizing large-scale behaviour via spatially averaged bifurcation diagrams. The key message is that, across a large range of parameter values, fluid flow can induce plankton blooms and mean-field population dynamics that are distinct from those predicted for well-mixed systems. The implications for oceanic population dynamic studies are manifest: we argue that the formation of HABs will depend strongly on the physical and biological state of the ecosystem, and that local increases in zooplankton heterogeneity are likely to precede phytoplankton blooms.

Harmful algal blooms in fresh and marine water systems: The role of toxin producing phytoplankton

2016 ◽  
Vol 09 (03) ◽  
pp. 1650043 ◽  
Author(s):  
Nilesh Kumar Thakur ◽  
S. K. Tiwari ◽  
Ranjit Kumar Upadhyay
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Functional Responses ◽  
Toxic Phytoplankton ◽  
Space And Time ◽  
Spatially Distributed ◽  
High Predation ◽  
Predator Switching ◽  
Parameter Values

In this paper, we have investigated a model with three interacting species: non-toxic phytoplankton, toxic phytoplankton and zooplankton with Holling type II and III functional responses over the space and time. The role of toxin producing phytoplankton (TPP) has been studied. We have presented the theoretical analysis of pattern formation in spatially distributed population with local diffusion. The paper highlights the heterogeneity of HABs over space and time. The choice of parameter values and the functional response is important to study the effect of TPP, also it would depend more on the nonlinearity of the system. With the help of numerical simulations, we have observed the spatial and spatiotemporal patterns for plankton system. This study demonstrates that TPP plays an important role in controlling the dynamics. We have observed that prey’s anti-predator efforts promote predator switching. It has been found that high predation of TPP helps for the coexistence of toxic, non-toxic phytoplankton and zooplankton population.

scholarly journals An Application of a Delay CSOH Model on the Coconut Farm

2019 ◽  
Vol 8 (6S3) ◽  
pp. 174-187
Keyword(s):  
Mathematical Model ◽  
Population Dynamics ◽  
Time Delay ◽  
Equilibrium Points ◽  
Critical Value ◽  
Interior Equilibrium ◽  
Fundamental Properties ◽  
Barn Owls ◽  
The Stability ◽  
The Mathematical Model

In this paper, we introduce the mathematical model that represents the quantity and population dynamics on the coconut farm. The model encompasses the number of coconuts and population of squirrels, barn owls, and squirrel hunters. We study the fundamental properties of the model that include positivity, boundedness, and equilibrium points. We also investigate the effect of the time delay on the stability of the equilibrium points. The results of the analysis show that when the time delay reaches its critical value, the interior equilibrium point lost its stability, and there occurs the Hopf bifurcation.

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