Optimization Analysis of Fishing Time and Feeding Strategy of

Freshwater Fisheries Based on System Dynamics Model

Jin Song

Agriculture and Rural Bureau of Ningyang County, Shandong 271400, China

Keywords: Swarm System Dynamics Model, Freshwater Fisheries, Fishing Time, Feeding Strategy.

Abstract: Platform. As an important food supply industry, the healthy and sustainable development of freshwater fishery

plays a role that cannot be ignored in terms of economic and ecological balance. In the face of limited

resources and a volatile environment, scientifically formulating fishing time and feeding strategies has

become the key to increasing yields and ensuring aquatic biodiversity. The application of system dynamics

model provides strong theoretical support and technical tools for solving this problem.

1 INTRODUCTION

The system dynamics model has the unique

advantage of simulating the interaction between

various elements in the freshwater fishery ecosystem

(Helena, 2024). By building models, we can clearly

see the impact of different fishing pressures and

feeding levels on fish stocks, so as to predict the long-

term effects under different management measures

(Fisheries Of The Northeastern United States, 2023).

This dynamic simulation not only helps us assess the

sustainability of existing policies, but also guides us

in developing more efficient fishing plans and feeding

strategies (Metcalfe, 2023).

2 ANALYSIS OF RATIONALITY

AS THE BASIS OF

QUANTIFICATION

2.1 Age Grouping and Promotion

Specifically, the choice of harvest time is a complex

decision-making process that requires a trade-off

between economic benefits and ecological health.

Systematic dynamics models can accurately describe

factors such as the growth cycle, breeding season

(Urbina, 2023), and natural mortality of fish stocks,

so that managers can harvest at the optimal time to

maximize economic benefits and ensure the

regeneration of fish stocks (Sara,2023). For example,

fishing avoids the breeding season of fish not only

helps to protect juvenile fish, but also maintains the

population and enables the sustainable use of

resources (Jun, 2023).

2.2 Catch Rate and Catch Rate

In addition, the optimization of feeding strategies is

equally important. Overfeeding or underfeeding can

have a negative impact on the water environment,

leading to deterioration of water quality and even

outbreaks of fish diseases (The Federal Register,

2023). The system dynamics model can simulate

water quality trends and fish health status at different

feeding frequencies and quantities to help managers

find the best feeding spots. This not only improves

feed utilization, reduces waste, but also contributes to

the maintenance of a good ecological environment.





()



= −𝜆𝑥(𝑡) −𝑣



(𝑡)

)

It is important to note that the system dynamics

model emphasizes holism and interactivity. It does

not look at fishing or feeding in isolation, but looks at

it in the context of the ecosystem as a whole (The

Federal Register, 2023). This holistic view allows us

to identify non-intuitive causal chains, such as

indirect effects of fishing intensity on water quality,

or potential impacts of feeding strategies on other

species, that are difficult to reach with traditional

methods.

Song, J.

Optimization Analysis of Fishing Time and Feeding Strategy of Freshwater Fisheries Based on System Dynamics Model.

DOI: 10.5220/0013535800004664

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 3rd International Conference on Futuristic Technology (INCOFT 2025) - Volume 1, pages 80-84

ISBN: 978-989-758-763-4

𝑉𝑥



(𝑡)

𝑏



)

It's called catch rates. that's how we got it.

𝑉𝑥



(𝑡)𝑑𝑡

𝑏



𝑥



(

𝑡

)

= 𝜇(𝑡)𝑑

)

In practice, applying system dynamics models

requires us to have an in-depth understanding of

ecosystems and accurate data support. This includes,

but is not limited to, key information such as fish

population dynamics, water quality parameters, food

web structure, etc (Barrett, 2023). Through the

detailed analysis of this data and the continuous

adjustment of the model, we can gradually

approximate the most reasonable harvest time and

feeding strategy.

𝑥



(𝑡)=𝑥



(𝑎) ⋅𝑒



)

In summary, the system dynamics model of

freshwater fisheries is a powerful tool that can help us

scientifically develop harvest timing and feeding

strategies. By simulating different scenarios, we can

better understand the complexity of fishery

ecosystems and make more informed decisions based

on them (Sin., 2023). This will not only increase

yields, but also ensure ecological health and diversity,

and promote the sustainable development of

freshwater fisheries.

dN=1.5cx₃(t)dt+3cx₄(t)dt

Freshwater fisheries, as an important link in the

global food supply chain, not only carry rich

biodiversity, but also one of the food sources on

which human beings depend.

𝑁=

𝑥



(𝑎) ⋅3𝑐

2𝑥



⋅1 −𝑒



)

However, in the development process of modern

society, freshwater fishery systems are facing

unprecedented challenges and changes. In this paper,

we will delve into the dynamics of freshwater fishery

systems and reveal the key variables and interaction

mechanisms, in order to provide scientific basis and

practical guidance for sustainable management in this

field.:

𝑥



𝑆𝑁

𝑆

𝑁

)

System dynamics theory provides us with a

methodology that combines macro and micro

perspectives, enabling us to fully understand causal

cycles in complex ecosystems. For freshwater

fisheries, system dynamics analysis helps us identify

key factors such as fish stock dynamics, water

quality, ecological changes, fishing pressure, and

climate change that shape the health and trends of

freshwater fisheries systems.

Fishing strategies for sustainable production in a

single year

Nonannual production means that the catch of fish

in a fishing area is constant at the start of each year.

X4 (1)= x4 (0), k=1,2,3,4.

First, fish stock dynamics are a core component of

freshwater fisheries systems. Fish catches are directly

affected by the increase or decrease in stocks, and the

growth potential of stocks is influenced by a

combination of factors such as food availability,

breeding conditions and natural mortality. For

example, overfishing can lead to a sharp decline in the

population of certain commercially valuable fish

stocks, which in turn affects the balance of the entire

ecosystem.

2.3 Fixed Rate Fishing Model

Water quality is then another key factor affecting the

health of freshwater fisheries systems. The discharge

of pollutants can reduce the oxygen content of the

water body and increase the number of harmful

bacteria, which is not conducive to the survival and

reproduction of fish and other aquatic organisms. In

addition, eutrophication often leads to blooms, which

not only disrupt the process of underwater

photosynthesis, but also directly poison aquatic life.

Then v₄(t)=bμx₄(t), and the differential equation

(1) is easily found.

x₄(t)=x₄(0)e-(a+b,a)

Let t=a be x(a)=x₄(0)y₄e-a^.

y=eb,n, and y is the damping factor for fishing,

which is called the external damping factor.

Environmental and ecological changes should not

be ignored, including changes in water connectivity,

habitat destruction, and invasion of alien species.:

⎩

⎨

⎧

𝑥



𝑠

𝐴

𝑥



+ 𝑦



𝑥



= 𝑥



+ 𝑥



⋅𝑦



⋅𝑒



𝑥



= 𝑥



⋅𝑦



)

These changes may pose a threat to native fish

stocks, disrupt the original ecological competition

and predation relationship, and ultimately lead to a

decline in species diversity

Optimization Analysis of Fishing Time and Feeding Strategy of Freshwater Fisheries Based on System Dynamics Model

⎩

⎪

⎨

⎪

⎧

𝑥



= 𝑠⋅

𝑠

𝐴

⋅𝑒



𝑒



−𝑦



𝑥

,,

+ 𝑦

,,

𝑥



= 𝑥



+ 𝑥



⋅𝑦



⋅𝑒



𝑥



𝑥



⋅𝑦



𝑒



−𝑦



)

These changes may pose a threat to native fish

stocks, disrupt the original ecological competition

and predation

𝐿





= 𝑠⋅

𝑥





𝐴

⋅𝑒



𝑒



−𝑦



𝑥







+ 𝑦







𝑑𝑡

)

In the face of these complex system elements and

their interactions, we must take a comprehensive

management approach.

𝐿





= 𝑠⋅

𝑏



𝑥



⋅𝜇𝑡⋅

𝜆+ 𝑏



𝜇

(10)

The total annual catch is as follows.

𝑤= 𝑝



⋅𝐿









(11)

b₁=b₂=0, and y₁=y₂=1,L₁=L₂=0.

It's necessary:

W=p₃L₃x₃+p₄L₄x.

In addition, the impact of climate change cannot be

underestimated. Rising temperatures and changing

precipitation patterns can lead to changes in water

temperature and water levels, which in turn affect fish

growth, reproduction, and migration patterns. The

frequency of extreme weather events can also cause

sudden and sudden blows to freshwater fisheries.

2.4 Drop Fishing Model

First of all, it should be clear that the dynamics of the

fishery system are not only reflected in the increase

and decrease of biomass, but also involve the

comprehensive effects of environmental factors,

economic conditions, policies and regulations. From

a biological point of view, biological parameters such

as the regenerative ability, growth cycle, and

reproductive habits of fish resources determine the

change law of fish population, while the changes in

the marine environment, such as increased water

temperature and increased pollution, indirectly affect

the structure of the food chain in the ecosystem.

In addition, the intervention of economic

activities has brought profound changes to the fishing

system. Problems such as resource depletion caused

by overfishing, damage to the ecological environment

by unsustainable fishing methods, and the impact of

market supply and demand on the price of fishery

products are all directly related to the healthy

development of the entire industry.

𝑙





= 𝑏



⋅𝜇





𝑥



𝑥



𝑑𝑡

(12

)

Therefore, it is particularly important to formulate

reasonable fisheries policies and management

measures. For example, the establishment of closed

seasons and areas, the limitation of net size, and the

implementation of quota systems can all effectively

reduce fishing pressure and create space for the

natural recovery of fish stocks.

𝑙



𝐸



𝐸



⋅

𝑏



⋅𝜇

𝜆+ 𝑏



(13

)

Furthermore, advances in science and technology

have provided new tools and methods for the study of

fishery system dynamics.

𝑙



= 𝑙









(14

)

The application of remote sensing technology can

monitor the environmental status of fishery in real

time, GIS system can analyze the spatiotemporal

pattern of fishery resource distribution, and

biomarker technology can help track the migration

path of fish, the combined application of these

technologies has greatly improved the efficiency and

accuracy of fishery management.

2.5 Case Calculation

Of course, the analysis of fishery system dynamics is

inseparable from the support of mathematical models.

By quantifying various biological, environmental,

and economic parameters, the establishment of

dynamic simulation models can help researchers and

policymakers predict future resource change trends,

evaluate the effects of different management

strategies, and make more scientific and reasonable

decisions..

Finally, the core purpose of fisheries system

dynamics research is to achieve sustainable use of

resources. In the face of the dual challenges of global

climate change and human activities, how to balance

economic benefits and ecological protection, and how

to balance short-term interests and long-term well-

being are all urgent questions to be answered in the

INCOFT 2025 - International Conference on Futuristic Technology

current fishery development. Therefore, the

exploration of multiple ways such as

multidisciplinary integration, international

cooperation and public participation is crucial to

promote the development of the fishery system in a

more stable, efficient and sustainable direction.

Table 1: The maximum yield of various fishing strategies.

Model Name

Maximum

Harvest

tons of initial

fish X

～X

Decision

Data

Fixed-rate fishing 387.7

119.5,53.70,

24.13,0.092

μ=17.02

Segment

reduction

rate

(

m=4

)

402.0

121.1,54.44,

24.46,0.274

=25

q=0.580

Concentrated peak

rate fishing

404.4

121.2,54.48,

24.48,0.310

μ=25

r=0.340

3 YEARS IS THE HDPE

CHENGYE PACKAGE

CAPTURE-UP STRATEGY

In summary, the overall analysis of fishery system

dynamics reveals many interaction and feedback

mechanisms in this complex system, which requires

us to consider not only the internal laws of biology,

but also the comprehensive effects of environmental

changes, human intervention, and scientific and

technological progress. Only by deeply

understanding and scientifically managing these

interrelated and dynamic processes can we truly

achieve the sustainable use of fishery resources and

ensure the long-term interests of human society and

the healthy harmony of marine ecosystems.

The complexity and variability of fishery systems

have always been the focus of research on the

sustainable use of natural resources and ecosystem

management in modern topics. In order to ensure that

fishery resources can be supplied to human society in

the long term, scientists have developed a powerful

tool - the fishery system dynamics model. This

mathematical model not only captures the intricate

interactions within ecosystems, but also provides the

scientific basis for predicting future trends and

guiding decision-making.

Table 2: Shows the maximum yields for the five-year

contract period.

Model name

Maximum number of changed

into a solution to mushroom

eginning ·

Decisio

data

kiloton x₁ (5)~x₄ (5)

Fixed-rate capture

1601

119.5,53.70,

24.15,0.093

μ=16.93

Fractional

reduction rate

fishing(m=4)

1655

121.2,54.44,

24.46,0.276

μ₁=25

q=0.577

Concentrated peak

rate fishing

1664

121.3,54.48,

24.48,0.311

μ=25

r=0.339

Constructing an effective model of fishery system

dynamics first requires an in-depth analysis and

understanding of the ecosystem under study. This

involves the quantitative description of the

relationship between fish population growth,

reproduction, mortality and predation, the

consideration of environmental factors such as

temperature, salinity, water current, etc., and the

integrated analysis of human activities such as fishing

intensity, fishing technology, policies and

regulations. These elements are intertwined to form a

complex and elaborate ecological web.

=0.267,r₁=0.290,r₂=0.340,r₃=r₄=0.339,W=1667.

In this network, each population does not exist in

isolation, they are connected to other populations

through food chains and living spaces. For example,

small plankton provide food for juvenile fish, and

adult fish can become prey for large predators. As a

result, when one link changes, the entire system can

be affected. This is exactly what kinetic models must

consider: how to model this chain reaction and its

impact on fishery resources.

Models are usually constructed using differential

equations or algebraic equations to represent the

dynamic relationships between the various

components in the system.

4 DIFFERENT FISHING

STRATEGIES

In practical applications, the establishment of

dynamic models is not achieved overnight. It requires

the collection of a large amount of field data to

support the estimation of model parameters. This

includes information on catch records, stock surveys,

environmental monitoring, and more. At the same

time, the validation and adjustment of the model is

Optimization Analysis of Fishing Time and Feeding Strategy of Freshwater Fisheries Based on System Dynamics Model

also an essential step, and scientists need to constantly

test and improve the model with new data to ensure

the accuracy and reliability of its predictions.

The value of the fishery system dynamics model

lies in its ability to predict the future, which provides

a scientific basis for decision-makers. In the face of

challenges such as overfishing, climate change,

habitat destruction, and more, a well-constructed and

validated model can demonstrate the potential long-

term impact of various management measures. Such

models can be used not only for resource

management, but also for assessing economic

benefits, ecological risks and social well-being, and

providing direction for sustainable fisheries.

In conclusion, fisheries system dynamics models

are powerful tools for understanding and managing

complex ecosystems. Not only does it reflect the

subtle relationship between populations and the

environment in nature, but it also provides us with a

window into the future. By continually researching

and refining these models, we can better grasp the

pulse of our fishery resources and ensure that the

precious resources that the ocean has given us are

sustainably harnessed, so that every corner of the blue

planet is full of life and hope.

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