Optimal Harvest Problem for Fish Population—Structural Stabilization

The influence of environmental conditions and fishery on a typical pelagic or semi-pelagic fish population is studied. A mathematical model of population dynamics with a size structure is constructed. The problem of the optimal harvest of a population in unstable environment conditions is investigat...

Full description

Bibliographic Details
Main Authors: Aleksandr Abakumov, Yuri Izrailsky
Format: Article
Language:English
Published: MDPI AG 2022-03-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/10/6/986
_version_ 1797445343701368832
author Aleksandr Abakumov
Yuri Izrailsky
author_facet Aleksandr Abakumov
Yuri Izrailsky
author_sort Aleksandr Abakumov
collection DOAJ
description The influence of environmental conditions and fishery on a typical pelagic or semi-pelagic fish population is studied. A mathematical model of population dynamics with a size structure is constructed. The problem of the optimal harvest of a population in unstable environment conditions is investigated and an optimality system to the problem research is constructed. The solutions properties in various cases have also been investigated. Environmental conditions influence the fish population through recruitment. Modelling of recruitment rate is made by using a stochastic imitation of environmental conditions. In the case of stationary environment, a population model admits nontrivial equilibrium state. The parameters of fish population are obtained from this equilibrium condition. The variability of environment leads to large oscillations of generation size. The fluctuations of the fish population density follow the dynamics of recruitment rate fluctuations but have smaller gradients than recruitment. The dynamics of the optimal fishing effort is characterized by high variability. The population and the average size of individuals decrease under the influence of fishery. In general, the results of computer calculations indicate the stabilization of the population dynamics under influence of size structure. Optimal harvesting also contributes to stabilization.
first_indexed 2024-03-09T13:25:24Z
format Article
id doaj.art-7c59ce38e93b4349a706fc0ad91ec11b
institution Directory Open Access Journal
issn 2227-7390
language English
last_indexed 2024-03-09T13:25:24Z
publishDate 2022-03-01
publisher MDPI AG
record_format Article
series Mathematics
spelling doaj.art-7c59ce38e93b4349a706fc0ad91ec11b2023-11-30T21:25:04ZengMDPI AGMathematics2227-73902022-03-0110698610.3390/math10060986Optimal Harvest Problem for Fish Population—Structural StabilizationAleksandr Abakumov0Yuri Izrailsky1Institute of Automation and Control Processes, Far Eastern Branch of the Russian Academy of Sciences, 5 Radio Street, 690041 Vladivostok, RussiaInstitute of Automation and Control Processes, Far Eastern Branch of the Russian Academy of Sciences, 5 Radio Street, 690041 Vladivostok, RussiaThe influence of environmental conditions and fishery on a typical pelagic or semi-pelagic fish population is studied. A mathematical model of population dynamics with a size structure is constructed. The problem of the optimal harvest of a population in unstable environment conditions is investigated and an optimality system to the problem research is constructed. The solutions properties in various cases have also been investigated. Environmental conditions influence the fish population through recruitment. Modelling of recruitment rate is made by using a stochastic imitation of environmental conditions. In the case of stationary environment, a population model admits nontrivial equilibrium state. The parameters of fish population are obtained from this equilibrium condition. The variability of environment leads to large oscillations of generation size. The fluctuations of the fish population density follow the dynamics of recruitment rate fluctuations but have smaller gradients than recruitment. The dynamics of the optimal fishing effort is characterized by high variability. The population and the average size of individuals decrease under the influence of fishery. In general, the results of computer calculations indicate the stabilization of the population dynamics under influence of size structure. Optimal harvesting also contributes to stabilization.https://www.mdpi.com/2227-7390/10/6/986mathematical modelharvestpopulation dynamicsoptimal controlenvironment
spellingShingle Aleksandr Abakumov
Yuri Izrailsky
Optimal Harvest Problem for Fish Population—Structural Stabilization
Mathematics
mathematical model
harvest
population dynamics
optimal control
environment
title Optimal Harvest Problem for Fish Population—Structural Stabilization
title_full Optimal Harvest Problem for Fish Population—Structural Stabilization
title_fullStr Optimal Harvest Problem for Fish Population—Structural Stabilization
title_full_unstemmed Optimal Harvest Problem for Fish Population—Structural Stabilization
title_short Optimal Harvest Problem for Fish Population—Structural Stabilization
title_sort optimal harvest problem for fish population structural stabilization
topic mathematical model
harvest
population dynamics
optimal control
environment
url https://www.mdpi.com/2227-7390/10/6/986
work_keys_str_mv AT aleksandrabakumov optimalharvestproblemforfishpopulationstructuralstabilization
AT yuriizrailsky optimalharvestproblemforfishpopulationstructuralstabilization