Fish Farming Development: A Model of Technical Skills and Intensive Care

Aftab Chowdhury

Fish and all aquatic animals live in water. Therefore, good water quality is essential for fish reproduction, taste and growth. As the intensity of fish farming increases, the importance of water management is also growing. Recently, it has been observed that many closed water bodies in Bangladesh are unsuitable for fish farming and are not being managed scientifically. Unequal water quality is also causing various diseases and pest infestations, resulting in the deaths of large numbers of fish, small shrimp and crabs.

An Aquaculture Pond Expert System can be used to analyze water quality for fish farming. The system can determine how to improve the environment for fish farming in the future and identify necessary precautions for production. It can also provide various recommendations related to water quality management. In addition, it can help address the shortage of people with adequate technical knowledge of fish farming and problems related to the slow exchange of information. An expert system for evaluating water quality in fish farming can be developed based on data collected from ponds or closed water bodies and the experience of experts. The system consists of four subsystems: database, knowledge base, model base and method base. These can help acquire knowledge, develop a knowledge base and make decisions through different methods. Through the model, water quality, future prospects and production-related guidelines can also be determined.

Structure and Function of the System

The Aquaculture Pond Expert System is based mainly on the knowledge base and model base. Its four subsystems are the knowledge base, database, model base and method base.

The knowledge base and model base are the principal components of the system. The knowledge base stores rules and regulations that can be used by the reasoning machine to make decisions. The model base contains models developed from water-quality data and serves as a major component of the system’s reasoning machine.

The model base contains two subsystems: an evaluation model and a prediction model. The evaluation model includes object evaluation, multi-object evaluation and synthetical evaluation. The prediction model includes a dissolved oxygen prediction model, nonlinear temperature model, BOD-DO multilinear model and dimension zoology model. The method base includes the classical evaluation method and fuzzy synthetical evaluation method.

Enriching Knowledge

Like other computer software, this system also requires sufficient knowledge and information. The quality and quantity of domain-expert knowledge are important for developing an efficient expert system. Proper knowledge acquisition and its appropriate representation are the main keys to the success of an expert system.

Environmental Standards and Principles

The system identifies the boundaries of environmental standards, which should be determined according to standards established by national environmental research laboratories and agencies. Water quality must also be suitable for fish farmers. These standards should be developed through long-term research and the knowledge of domain experts. This will help the system adapt to the overall conditions of the country and provide appropriate guidance and control.

Expert Experience

The knowledge base is the main component of an expert system and is developed from expert experience. Such experience can be collected from several experts who have been involved in aquaculture water environments for many years. The experience of domain experts can also be made useful through detailed observation and analysis. The system can also be enriched by collecting basic theories, methods and research-based knowledge from different books. Information on water quality assessment, mathematical models of water quality, grey correlation degree evaluation and fuzzy synthetical evaluation can provide the system with strong theoretical and scientific foundations.

General Characteristics of Water Quality in Closed-Water Fish Farming

Knowledge of water quality is essential for fish farming in ponds or closed water bodies. It is related to biology, water conservation, hydrology and meteorology.

Experience: Experience becomes increasingly valuable during water-quality assessment. Water quality can be evaluated by observing its color and transparency. The condition of dissolved oxygen can also be assessed by observing fish behavior.

Data Charts: Closed water bodies contain large amounts of data, which can be presented in table format. Analysis, possibilities and evaluation results can be shown in tables, making the data easier for users to understand. Such data can also support the expert system in machine-learning applications.

Many countries around the world have already conducted research on the quality of river water. Later, research began on the quality of water in lakes and reservoirs. However, research on pond water quality has not yet reached the same level. There are still gaps in specific perspectives and objectives, and further research can help reduce these limitations.

Production Rules in Water Quality Evaluation Knowledge

The basic form of water-quality evaluation in the Aquaculture Pond Expert System is generally represented through production formalism. P represents the production premise, through which the initial, current and previous conditions can be analyzed. Q represents the production operation or final decision. When a condition is consistent with premise P, a decision or action can be inferred or carried out.

Example

Previous condition: The water is blue and green, blue-green algae are dominant, and the water is not sufficiently clean. To treat the water, it should first be cleaned with bleach and then purified using dipterox-containing moram sulfate. This is a simple production rule.

The premises concerning the environmental condition of pond water may sometimes be simple, but most premises are complex. The environmental quality of pond water is also highly complex. Although the ecosystem of a closed water body is smaller than those of the sea, lakes and reservoirs, it contains characteristics of other ecosystems. Therefore, the environmental information of pond or closed-water ecosystems is complex, and its production rules can also be complicated. Ultimately, the environmental quality of water depends on the overall condition of the pond.

Author: Journalist and Columnist.