Fisheries harvest management procedures under time-varying productivity
department or school: Science, Faculty of
department or school: Oceans and Fisheries, Institute for the
data provider: DSpace
degree campus: UBCV
creator: Licandeo, Roberto
issued: 2020-04-24T14:35:13Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Fish stocks often show persistent changes in fish production with hypothesized causes including time-varying recruit parameters, natural mortality of mature fish, and somatic growth. Changes in fish productivity can affect biological reference points and the expected robustness of harvest strategies in meeting long-term conservation and economic objectives. Current assessment approaches commonly assume “stationarity” in stock-recruit parameters and implemented harvest strategies commonly lack consideration of changes in fish productivity. This dissertation covers three studies based on statistical analysis and simulation methods that aim to advance understanding of time-varying stock-recruit parameters and harvest control rules (HCRs) to cope with changes in fish production. Chapter 2 examined the performance of a Kalman filter algorithm that estimates dynamic state variables (e.g., changing stock-recruit parameters) from inaccurate observations obtained from stock assessment outputs. In Chapter 3, stochastic optimization in policy space (SOPS) was used to find an optimal HCR that is robust to changes in productivity under closed-loop simulation or management strategy evaluation (MSE). By using SOPS and a simple population dynamics model, this chapter examined optimal HCRs under different types of regime shifts (e.g., changes in carrying capacity and intrinsic growth rates). Chapter 4 examined empirical HCRs in an extreme situation of “non-stationarity” in stock-recruit parameters (i.e., a spasmodic recruitment pattern), using Atlantic redfish stocks as a case-study. The Kalman filter detected the overall trend in the stock-recruit parameters over time. Also, it was found that optimal HCRs depend on the timing of biomass estimates relative to harvest, observation error, intrinsic population growth, and regime shifts types. In the case of spasmodic stocks, it was found that simple HCRs that used data from well-designed fishery-independent resource surveys were capabl…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/74142
note: Fisheries harvest management procedures under time-varying productivity by Roberto Licandeo M.Sc., Fisheries. University of Concepcion, Concepcion, Chile B.Sc., Marine Biology, Austral University, Valdivia, Chile. A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Oceans and Fisheries) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2020 © Roberto Licandeo, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Fisheries harvest management procedures under time-varying productivity_______________ submitted by Roberto Licandeo in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Institute for the Oceans and Fisheries Examining Committee: Dr. Murdoch McAllister, Institute for the Oceans and Fisheries, UBC Supervisor Dr. Carl Walters, Institute for the Oceans and Fisheries, UBC Supervisory Committee Member Dr. Villy Christensen, Institute for the Oceans and Fisheries, UBC Supervisory Committee Member Dr. Marie Auger-Méthé, Department of Statistics and Institute for the Oceans & Fisheries , UBC University Examiner Dr. Peter Arcese, Department of Forest and Conservation Sciences, UBC University Examiner iii Abstract Fish stocks often show persistent changes in fish production with hypothesized causes including time-varying recruit parameters, natural mortality of mature fish, and somatic growth. Changes in fish productivity can affect biological reference points and the expected robustness of harvest strategies in meeting long-term conservation and economic objectives. Current assessment approaches commonly assume “stationarity” in stock-recruit parameters and implemented harvest strategies commonly lack consideration of changes in fish productivity. This dissertation covers three studies based on statistical analysis …
has type: Thesis/Dissertation
date issued: 2020-05
is shown at: 10.14288/1.0389968
language: eng
degree discipline: Oceans and Fisheries
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/74142