Chalmers Conferences, 9th European Conference on Mathematical and Theoretical Biology

An effect of optimal harvest on an evolution of population with age structure
Oksana Zhdanova

Last modified: 2014-04-01


The main problem of dynamic population theory is the describing of nature and the mechanism explanation of fluctuating behavior (quasiperiodic and periodic) of population size. The decision of important applied task notably the development of optimal strategy of commercial species exploitation sides with this problem.

The two types of issues appeared when attempts of ecological and population-genetics theory combination were made and these issues are under consideration of evolutionary-ecological theory. The first type of issues is investigation of evolution factors effect (most of all the natural selection) on genetic structure changes and dynamic behaviour of population under the limited ecological resources. The second one is analyses necessity of consequences of harvest. The conception of maximal equilibrated catch asserts that harvested populations are not in the same ecological conditions as non-harvested ones. So the conditions of selection and hence fitnesses of genotypic groups can changes in harvested populations.

This work considers the results of optimal equilibrium harvest with constant quota in two-aged population.

It has been shown analytically that maximum of equilibrium harvest income is reached never when both age groups are harvested simultaneously. The optimal strategy of harvest is the catch of fixed portion from single age group.

It has been shown that even when catch of fixed portion from single age group is realized independently from individuals’ genotypes the type of genetic equilibrium can change. As general income from single age-group individuals harvest depends from catch volume as well as from market price of this age-group individuals, so any market variations dealing with changes in market prices of one age-class individuals can lead to situation where the most profitable exploitation strategy becomes one with catch from other population age-group and so the type of genetic equilibrium can changes.


population genetic structure, optimal harvest, natural selection