Multiple-year optimization of conservation effort and monitoring effort for a fluctuating population

Hiroyuki Yokomizo, Patsy Haccou, Yoh Iwasa

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We consider optimal conservation strategies for an endangered population. We assume that juvenile survival is affected by unpredictable environmental fluctuation and can be improved by costly conservation effort. The initial population size is not accurately known at the time that the conservation effort level is chosen, but the uncertainty of its estimate can be reduced by a costly monitoring effort. In a previous paper, we analysed the optimal management strategy that minimizes a weighted sum of extinction probability and economic costs when only a single year is considered. Here we examine the case in which the conservation period lasts for several years by dynamic programming with incompletely observed process states. We study the optimal levels of the conservation and the monitoring efforts, and their dependence on the length of the conservation period and other parameters. The main conclusions are: (1) The optimal conservation effort in the first year depends on the accuracy of the information on the population size in the first year, but is almost independent of the accuracy of the information in later years. (2) When the risk of population extinction is small, the optimal conservation effort increases with the uncertainty of the population size. In contrast when the population is endangered, the optimal conservation effort decreases with the uncertainty of the population size. (3) The optimal conservation and monitoring efforts both increase with the length of the conservation period, provided that the population is relatively safe. However, if the population is endangered, both types of effort become smaller when the conservation period increases.

Original languageEnglish
Pages (from-to)157-171
Number of pages15
JournalJournal of Theoretical Biology
Volume230
Issue number2
DOIs
Publication statusPublished - Sep 21 2004

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Conservation
Population Density
Monitoring
population size
Optimization
monitoring
Uncertainty
uncertainty
Population
Population Size
extinction
dynamic programming
economic costs
Economics
Costs and Cost Analysis
Extinction Probability
Weighted Sums
Dynamic programming
Extinction
Dynamic Programming

All Science Journal Classification (ASJC) codes

  • Statistics and Probability
  • Modelling and Simulation
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Agricultural and Biological Sciences(all)
  • Applied Mathematics

Cite this

Multiple-year optimization of conservation effort and monitoring effort for a fluctuating population. / Yokomizo, Hiroyuki; Haccou, Patsy; Iwasa, Yoh.

In: Journal of Theoretical Biology, Vol. 230, No. 2, 21.09.2004, p. 157-171.

Research output: Contribution to journalArticle

Yokomizo, Hiroyuki ; Haccou, Patsy ; Iwasa, Yoh. / Multiple-year optimization of conservation effort and monitoring effort for a fluctuating population. In: Journal of Theoretical Biology. 2004 ; Vol. 230, No. 2. pp. 157-171.
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