Environment Influence on the Phytoplankton Distribution in a Basin

Abakumov, A.I.

doi:10.17537/2012.7.274

Cited by 8 publications

(2 citation statements)

References 7 publications

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“…Традиционно данные появлялись из анализа образцов, взятых с борта судов, находящихся в море, что позволяло получить лишь нерегулярные и существенно неоднородные оценки его обилия. В последнее время появилась возможность использовать спутниковые наблюдения, при этом идентификация и интерпретация той части спектра излучения, которая связана с планктоном, остается чрезвычайно сложной задачей [напр., [8][9][10][11][12][13][14]. Поэтому теоретическое моделирование динамики обилия планктона необходимо для понимания физических процессов, влияющих на его динамику и последствия ее изменения для океанов и атмосферы.…”

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Discrete-Time Model of Seasonal Plankton Bloom

Неверова¹,

Zhdanova²,

Abakumov³

2020

Math.Biol.Bioinf.

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The most interesting results in modeling phytoplankton bloom were obtained based on a modification of the classical system of phytoplankton and zooplankton interaction. The modifications using delayed equations, as well as piecewise continuous functions with a delayed response to intoxication processes, made it possible to obtain adequate phytoplankton dynamics like in nature. This work develops a dynamic model of phytoplankton-zooplankton community consisting of two equations with discrete time. We use recurrent equations, which allows to describe delay in response naturally. The proposed model takes into account the phytoplankton toxicity and zooplankton response associated with phytoplankton toxicity. We use a discrete analogue of the Verhulst model to describe the dynamics of each of the species in the community under autoregulation processes. We use Holling-II type response function taking into account predator saturation to describe decrease in phytoplankton density due to its consumption by zooplankton. Growth and survival rates of zooplankton also depend on its feeding. Zooplankton mortality, caused by an increase in the toxic substances concentration with high density of zooplankton, is included in the limiting processes. An analytical and numerical study of the model proposed is made. The analysis shows that the stability loss of nontrivial fixed point corresponding to the coexistence of phytoplankton and zooplankton can occur through a cascade of period doubling bifurcations and according to the Neimark-Saker scenario leading to the appearance of quasiperiodic fluctuations as well. The proposed dynamic model of the phytoplankton and zooplankton community allows observing long-period oscillations, which is consistent with the results of field experiments. As well, the model have multistability areas, where a variation in initial conditions with the unchanged values of all model parameters can result in a shift of the current dynamic mode.

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Discrete-Time Model of Seasonal Plankton Bloom

Неверова¹,

Zhdanova²,

Abakumov³

2020

Math.Biol.Bioinf.

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“…This is due to the fact that changes in the state of the photosynthetic apparatus are accompanied by a change in the probability of electronic excitation energy quenching of chlorophyll-a, which appears to change intensity of LIF at the light. The study of photosynthesis using the kinetics of fluorescence allows the detection of damage under the influence of anthropogenic pollution, increasing the intensity of the sun and UV radiation, a lack of mineral nutrients, temperature, well before they will find their external manifestation, for example, in reducing the number of cells [26,29,30]. In the state, where the RC of phytoplankton cells are "closed" (quinone acceptor Q A is in a reduced state), the fluorescence quantum yield of chlorophyll-a in the PS2 is considerably greater than for Q A in the oxidized state.…”

Section: Lif Spectra Analysis As a Methods Of Research Of Phytoplanktomentioning

confidence: 99%

Biosensors Based on Micro-algae for Ecological Monitoring of the Aquatic Environment

Voznesenskiy¹,

Popik²,

Gamayunov³

et al. 2016

Algae - Organisms for Imminent Biotechnology

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This chapter is devoted to research possibilities of using micro-algae as sensor elements for biological sensors of aquatic pollutants. The characteristics of the fluorescence of microalgae pigments caused by laser light, called laser-induced fluorescence LIF , were used as informative parameters. It is shown that the functioning of biological sensors is determined by the consistency and concentration of micro-algal cells as well as their internal state, which depends on the temperature, illumination, and chemical composition of the water. The results indicate a significant dependence of the LIF intensities of micro-algae from exposure of heavy metal ions, temperature, and illumination. In text is demonstrated specificity of the reaction of various micro-algae, belonging to different phylum. This fact can be used for identify the phylum of micro-algae in situ, and for the creation the biosensors of ecological monitoring aquatic environment.Keywords: laser-induced fluorescence, micro algae phylum, ions of heavy metals, depending on the lighting and temperature, biosensors . IntroductionMonitoring of aquatic environments requires obtained information in real time, long before the appearance of visible signs of pollution, far exceeding the norms of maximum permissible concentrations MPC . In recent years, organisms, which have high sensitivity to adverse factors, are widely studied as bio-indicators for water monitoring. Single-celled organisms including Unicellular microorganisms violation of life appears to change their functioning reversibly or irreversibly. In the latter case usually occur damage cells, typically leading to its destruction. The initial, specific impact of the damaging environmental factor is aimed at very specific molecular structure of the cells. The composition of unicellular organisms mainly includes nucleic acids, proteins, lipids, and polysaccharides. "ll these components may be the target for of the damaging action of factors of the environment surrounding the cell. Violation of the functions of these structures causes a cascade of events that ends with response of the cell as a whole system. Thus, it is possible to distinguish several stages cellular response to external adverse impact. "s a rule, at first, there is a nonspecific reaction, typical for any irritations. For most of the cells, there is a change of cell membrane permeability during the action of metal ions [ ] and subsequent activation of intracellular systems aimed at the suppression of stress reactions and stabilization of intracellular metabolism [ ]. For example, in the presence of calcium ions at the initial stage is an activation of different intracellular systems protein kinases, phospholipases, protein biosynthesis systems, phosphodiesterase, cyclic nucleotides, adenylatecyclase, a contractile apparatus of the cell, etc. This is the first, reversible stage when the cell tries to compensate the effect of damaging factors. When the damaging factor is greater or more prolonged exposure, violation of cellular fu...

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