Mathematical modelling of a fish pond ecosystem

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.

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

2018

Recruitment and sustainability for fish population are renewable natural resources, if correctly managed. The basic purpose of fish recruitment and sustainability is to provide advice on the optimum exploitation level of aquatic living resources such as fish. We formulate a mathematical model for recruitment and developmental sustainability of fish population in the pond by modifying growth model of Verhuls where we incorporate catch equation of Baranov as a function of time in the model. Runge-Kutta scheme of fourth order was used to solve the modified model. Furthermore, we collected data from Federal University Wukari fish pond to validate our modified model. We coded the Runge-Kutta scheme for our modified model by using Octave programming language, results are shown on Table 2 and figure 1, 2, 3, 4 and 5. It was observed that at P=1, P=20, P=100 and P=300 the fish recruited started increasing from 1st month to 5th month and at 6th month the fish population decrease equally beca...

African Journal of Environmental Science and Technology, 2010

2= 0. 87) for model calibration and (r 2 = 0.88) for model validation. Simulation results also showed a general decrease of DO with time in 13 days by 28 and 38% for first and second batch, respectively. Thus, the model developed in this study could be used to predict the DO dynamics in fish ponds. Based on the model results, successful cultivation of healthy fish may require that retention time for water in the fish pond be 10 days.

Aquacultural Engineering, 2003

A dynamic model was developed to explain food nutrient dynamics in a semi-intensive aquaculture pond and to determine food nutrient requirements for supplementary feeds for Nile tilapia. The model links food nutrient production with elementary nutrient dynamics and fish growth by including four sectors: food nutrients, fish growth, elementary nutrients, and dissolved oxygen. The model, developed by using STELLA II software, simulated a field experiment that was designed to determine limiting nutritional factors for fish growth in fertilized ponds. Simulation results show that supplementary feeding compensates for natural food nutrient deficiencies. Results also reveal that protein supplements are necessary for increasing fish yields of fertilized ponds. Comparison of the data from simulation and observation indicates that the simulation values have a close correspondence with observed data, and the model is able to capture essential food nutrient dynamics in semi-intensive aquaculture ponds. #

In this paper the fundamentals of modeling and simulation are discussed. Simulation experiments are designed for plant growth and population of Salmon fish. Problem on bionomic equilibrium of multi-species fish model of Kar-Chaudhri's([15]) including stability properties studied .The impulsive fish model of Pandit and Deo([13 ]) and Oyelami and Ale ([12]) type of fish and fish-hyacinth are considered including stability property of later investigated. The investigation is carried out using both quantitative and qualitative techniques with the simulation experiments designed using mathlab software.

Ecological Modelling, 183: 11-28 (2005)

""A continuous deterministic model is proposed for qualitatively simulating the dynamics of an experimental aquaculture plant. The governing equations are ordinary differential equations. The state variables are considered in terms of biomass or concentrations and the equations are built according to balance arguments. The aquaculture plant may be represented in terms of two main elements: the tanks, where different species of fish are grown, and a pond, that provides for phytodepuration of the waste water of the tanks. The main forcing functions are temperature and solar radiation. The state variables are fish, feed and detritus in the tanks, while nutrients, phytoplankton, macrophytes, bacterial pool and detritus are those considered in the pond. A daily exogeneous input of fish feed is also considered. The model takes into account for both diel and seasonal variability.""

2018

The available forecasting models for growth pattern in fish are based on either classical approach or a particular growth model. In the present study, reparamerisation methodologies were attempted for forecasting growth of fish cultured in cemented ponds of plain areas. Forecasting methodology is not readily available for any other types of ponds for uplands of India. So, other appropriate growth curves (Logistic, Gompertz and von-Bertalanffy) were considered while developing the most suitable model for forecasting fish (common carp Cyprinus carpio var communis and silver carp Hypophthalmichthys molitrix) production from cemented ponds. Gompertz-1 and Logistic-1 models gave the best fit as well as fish yield forecasting, two months ahead from various ponds

IFAC Proceedings Volumes, 1987

A model of fish growth is formalized. The parameters are determined by aquaria experiments with rainbow trout (SaZmo ga i rdn eri). From the model the following terms can be found independently : Ingested food, growth , production of ammonia-nitrogen, settable and non-settable faeces , and oxygen consumption. Ingested food is determined as a function of temperature and fish size. The other terms are determined as functions of ingested food , temperature and fish size. The terms are balanced in energy or nitrogen. The model can e. g. be used in connection with production planning in fish farms and as a submo de l i:o "l'1uatic e c osystems.

To study the complex aquaculture problems covering fish growth, pond ecology and environmental parameters exploratory data analysis is done using multiple linear regression models for model development.