Mathematical modeling of dissolved oxygen in fish ponds

Scientific Reports

The main aim of this research is to develop a mathematical model to predict the dissolved oxygen in recirculating aquaculture system. The oxygen consumption of the model through the fish respiration and nitrification and the oxygen addition of the model through oxygen generator and water pumping. The effect of different water temperatures (24, 26, 28, 30 and 32 °C) on the dissolved oxygen consumption through fish respiration, biofilter and nitrification and fish growth were studied. An experiment to measure oxygen consumed by fish respiration and biofilteration and fish growth with the growth period and to validate the model results was carried out. The oxygen consumption predicted by the model was in a good agreement with those measured by the system. The oxygen consumption by fish respiration ranged 12.04 to 47.53 g O2 m−3 h−1 experimentally, while it was from 12.01 to 46.06 g O2 m−3 h−1 theoretically. The predicted and measured oxygen consumption through biofilteration values ran...

Ecological Modelling, 1984

Svirezhev, Yu.M., Krysanova, V.P. and Voinov, A.A., 1984. Mathematical modelling of a fish pond ecosystem. Ecol. Modelling, 21: 315-337.

Ecological Modelling, 2012

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Journal of the World Mariculture Society, 2009

A computer model of a f e r t i l i z e d warm-water aquaculture pond has been developed. The model i s intended t o represent the pond ecosystem and i t s response t o e x t e r n a l s t i m u l i . The major physical, chemical, and b i o l o g i c a l processes and parameters a r e included i n t h e model. A t o t a l of 22 s t a t e v a r i a b l e s a r e used i n t h e model (dissolved oxygen, ammonia, a l k a l i n i t y , phytoplankton, zooplankton, f i s h , e t c . ) . The model is fonnul a t e d as a system of m a s s balance equations. The d i f f e r e n t i a l equations include stimulatory and i n h i b i t o r y e f f e c t s of environmental parameters on processes taking place i n t h e pond. t h e e n t i r e growth period and d i u r n a l a s w e l l a s seasonal f l u c t u a t i o n s may be i d e n t i f i e d . The equations may be solved f o r

International Journal of Applied Physics and Mathematics, 2016

In this paper a nonlinear mathematical model is proposed to analyze the effect of decreasing level of dissolved oxygen on the survival of aquatic species in the water body in the presence of nutrients. This model has four nonlinear differential equations consisting of four state variables accounting for concentration of nutrients, density of algae, density of fish population, and concentration of dissolved oxygen. The three equilibrium points have been obtained to understand the dynamic behavior of the system. The conditions for existence of these equilibrium points are obtained. The stability analysis is conducted on each equilibrium point by considering variational matrix and using Routh-Hurwitz criteria. The nonlinear stability behavior of an equilibrium point considered to be critical is analyzed by applying Liapunov's direct method.

IRJET, 2021

Mathematical Model used to stimulate the water quality and the processes of self-purification of water bodies are important tools to support the water resources management. A framework of Dissolved oxygen (DO) modelling of the Thenkarai pond has been developed based on a combination of laboratory measurement and field and monitoring data. The model is based on the basic principles of the Streeter Phelps model equation. The main objective of the present study was to develop and demonstrate the use of a rather simple water quality model as a tool for the evaluation of alternative water management scenarios for the pond. The model is an extension of the Streeter-Phelps model and takes into account the physic-chemical and biological processes most relevant to modelling the quality receiving water bodies. To calibrated the results in various time interval with oxygen deficit based on the Oxygen sag curve. The analysis of the oxygen sag curve can be easily done by the superimposing the rates of deoxygenation and reoxygenation as suggested by the Streeter-Phelps analysis. Based on the results, a definite trend of dissolved oxygen concentrations was observed in the pond

Developments in Aquaculture and Fisheries Science, 1997

ENVIRONMENTAL SYSTEMS RESEARCH, 1993

The accurate prediction of dissolved oxygen(DO) in lakes specially in eutrophic lakes is of paramount importance in view of the water quality. The temporal and spatial variations of DO in the lake Calhoun is studied with the aid of a numerical model. When the water quality is found to be highly degraded, the DO depletion may cause fish kills and anoxic conditions for other living organisms in the ecosystem. The main factors that affect the DO budget are temperature and organic matters present. Computational values and measured values of DO are compared. The model predicts that at the surface, reaeration is predominant whereas photosynthesis and algal respiration contribute considerably.For the management point of view, it is useful to predict water quality in terms of DO, thereby, if necessary, remedial measures such as artificial aeration can be adopted to improve the water quality. The model prediction also provides an idea about the period during which an improvement is necessary without extensive costs.

Aquaculture Research, 1988

The application of computer modelling to the study of aquaculture ponds is reviewed. Two basic types of models are identified: empirical and mechanistic. In empirical modeis, the pond system is treated as a 'black box', and the relationship between inputs and outputs is determined by statistical analysis of data. In mechanistic models ('internally descriptive'), processes taking place within the pond are identified and described mathematically. A framework for the development of a mechanistic model of an aquaculture pond is presented. Sample formulations for some critical variables are discussed.

Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2006

Water quality management is a key factor in intensive fish culture. Higher stocking densities, intensive feeding and released metabolites may cause rapid deterioration of water quality (MILSTEIN 1990). Secondary reservoirs are mostly used to regulate and store water for irrigation to be used under unfavourable conditions ofwater availability. Water exchange due to irrigation water routing through such reservoirs provides an opportunity for maintaining a water quality regime at optimum level for intensive fish production. However, for groundwater-fed systems, some aeration mechanism is necessary to replenish dissolved oxygen (DO) levels in the pond water during water exchange (Bovo 1998). Hence, the two distinct uses of the secondary reservoir (irrigation regulation and fish culture) need to be balanced to accrue optimum benefits from each use. The concept o f fish pond-cum-secondary reservoir (Fig. l)

Jurnal Teknologi, 2016

This study presents a mathematical model for wastewater treatment process (WWTP) of an oxidation pond. The model permits investigating the effects of a biological-based product called mPHO on the degradation of contaminants as well as increase the amount of dissolved oxygen (DO) in the pond. At this aim, an ordinary differential equation with coupled equations has been developed to study the correlation between the amount of bacteria (phototrophic and Coliform), chemical oxygen demand (COD), and dissolved oxygen (DO) existing in the pond. The mathematical model is employed to simulate the behaviour of the system where the numerical results demonstrate that the proposed model gives a good approximation of the interaction processes that occur naturally between biological and chemical substances involved in the pond

International Journal of Science and Engineering, 2013

The development of aquaculture system should meet the community's basic need economically by taking into account the carrying capacity and environmental sustainability. The development of the environmentally friendly system such as silvofishery is being promoted by government however its yield has not reached the target yet. Dissolved oxygen availability is an important indicator which determines the success of the aquaculture system. The objective of the research was to determine dissolved oxygen availability on traditional pond systems using silvofishery pattern. Time series data collection was conducted once in 14 days with 2 measuring times; in the morning (06.00 am) and in the evening (06.00 pm) for 112 days. The research was conducted at four different silvofishery pond patterns, Pond Pattern 1 (0% mangrove canopy covered), Pond Pattern 2 (35% mangrove canopy covered), Pond Pattern 3 (67% mangrove canopy covered), and Pond Pattern 4 (75% mangrove canopy covered). Measurement was observed openly in the pond (in situ) with parameters: dissolved oxygen, temperature, Water pH, Salinity, Transparency, Wind Speed, and Depth of Water Table, while chlorofil-a was ex-situ measured. The result from each parameter was compared to optimum concentration rate for shrimp growth. From the experiment, Pond Pattern 1 showed the most satisfaction results. Its dissolved oxygen availability during the research was ≥ 4 mg/L which was 5.88 mg/L ±0.48 mg/L in the evening (06.00 pm) and 4.33 mg/L ±1.24 mg/L in the morning (06.00 am). It was also supported by optimum condition of other parameters such as temperature, Water pH, Salinity, Wind Speed, and Depth of Water Table. However, it was not supported by fertility and transparency of water. Thus, the traditional pattern of conservation still needs additional technology to maintain adequate dissolved oxygen availability for optimum shrimp growth.

Modeling Earth Systems and Environment, 2016

In this paper, a nonlinear mathematical model is proposed and analyzed to study the depletion of dissolved oxygen and survival or extinction of fish population in a nutrient enriched aquatic ecosystem. It is assumed in the model that there is an external constant input of nutrients (phosphorus and nitrogen) in the water body on account of anthropogenic activities. Stability analysis of the equilibria of the model is carried out and from the analysis it is shown that the fish population will survive at very low equilibrium level due to reduced concentration of dissolved oxygen and excessive presence of algal biomass on account of nutrient loading. Further, it is shown in this paper that the fish population tend to extinction due to decrease in the concentration of dissolved oxygen from its threshold level. Numerical simulations are also carried out in this paper to support the analytical results.

Transactions of the American Fisheries Society, 1973

The rate of oxygen consumption by organisms in pond waters, as measured by a dark bottle technique r a 24-hr period, increased with increasing chemical oxygen demand (COD). Rate of oxygen ,rsumption increased with temperature between 15 and 35 C (Qiu values were 1.5 to 2.0). At the same level of COD, oxygen consumption was greater in unaltered pond water than ill %%ll,. ill which the plankton was heat-killed and oxygen was utilized only by bacteria and other decomposers. COD was positively correlated with increasing concentrations of chlorophyll in pond waters. The amount of COD in soluble organic matter ranged from 20.2 to 95.0% of the Iota] COD. The percentage of the COD in the soluble fraction decreased with increasing quantities of phytoplankton. The average amounts of oxygen (mg oxygen/mg dry wt) required to completely oxidize various types of biological material were; phytoplankton from pure cultures 1.29, macroscopic algae 1.00, higher aquatic plants 0.99, particulate matter from pond waters 0.98, and fish 1.19.

Aquacultural Engineering, 2012

Several linear and non-linear models for centralized remote-control systems that can support decision making of semi-intensive aquaculturists concerning the inflow rates to the ponds were evaluated. These models were: multiple linear regressions (MLRs), generalized additive models (GAMs), artificial neural networks (ANNs) and fuzzy logic controllers (FLCs). These modeling techniques were applied in a semiintensive gilthead seabream (Sparus aurata) fishfarm located in southern Spain. The water temperature, ammonia concentration, turbidity and dissolved oxygen concentration in the ponds were measured and used as independent variables. Of all the approaches employed to simulate the actual water exchange operation in the ponds, the best fits were obtained using ANN and FLC models with only three input variables (turbidity measured at the input of the ponds and dissolved oxygen measured at the input and output of the ponds). These models provided levels of correlation between 0.73 and 0.75. In contrast, the best GAM and MLR models provided correlation coefficients of only 0.38 and 0.33, respectively. In spite of the results being statistically significant, the explained variance levels obtained indicate how difficult it is to capture the experience and knowledge of the aquaculturist concerning the operation of the water exchange in the ponds for maintaining the water quality in these production systems.