Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated?
Models for fluctuations in size of fish stocks must include parameters that describe expected dynamics, as well as stochastic influences. In addition, reliable population projections also require assessments about the uncertainties in estimates of vital parameters. Here we develop an age-structured...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Online Access: | http://dx.doi.org/10.1139/f07-074 http://www.nrcresearchpress.com/doi/pdf/10.1139/f07-074 |
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crcansciencepubl:10.1139/f07-074 2024-04-28T08:05:28+00:00 Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? Aanes, Sondre Engen, Steinar Sæther, Bernt-Erik Aanes, Ronny 2007 http://dx.doi.org/10.1139/f07-074 http://www.nrcresearchpress.com/doi/pdf/10.1139/f07-074 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 64, issue 8, page 1130-1142 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2007 crcansciencepubl https://doi.org/10.1139/f07-074 2024-04-02T06:55:54Z Models for fluctuations in size of fish stocks must include parameters that describe expected dynamics, as well as stochastic influences. In addition, reliable population projections also require assessments about the uncertainties in estimates of vital parameters. Here we develop an age-structured model of population dynamics based on catch-at-age data and indices of abundance in which the natural and fishing mortality are separated in a Bayesian state–space model. Markov chain Monte Carlo methods are used to fit the model to the data. The model is fitted to a data set of 19 years for Northeast Arctic cod (Gadus morhua). By simulations of the fitted model we show that the model captures the dynamical pattern of natural mortality adequately, whereas the absolute size of natural mortality is difficult to estimate. Access to long time series of high-quality data are necessary for obtaining precise estimates of all the parameters in the model, but some parameters cannot be estimated without including some prior information. Nevertheless, our model demonstrates that temporal variability in natural mortality strongly affects perceived variability in stock sizes. Thus, using estimation procedures that neglect temporal fluctuations in natural mortality may therefore give biased estimates of fluctuations in fish stock sizes. Article in Journal/Newspaper Arctic cod Arctic Gadus morhua Northeast Arctic cod Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 64 8 1130 1142 |
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Open Polar |
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Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Aanes, Sondre Engen, Steinar Sæther, Bernt-Erik Aanes, Ronny Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Models for fluctuations in size of fish stocks must include parameters that describe expected dynamics, as well as stochastic influences. In addition, reliable population projections also require assessments about the uncertainties in estimates of vital parameters. Here we develop an age-structured model of population dynamics based on catch-at-age data and indices of abundance in which the natural and fishing mortality are separated in a Bayesian state–space model. Markov chain Monte Carlo methods are used to fit the model to the data. The model is fitted to a data set of 19 years for Northeast Arctic cod (Gadus morhua). By simulations of the fitted model we show that the model captures the dynamical pattern of natural mortality adequately, whereas the absolute size of natural mortality is difficult to estimate. Access to long time series of high-quality data are necessary for obtaining precise estimates of all the parameters in the model, but some parameters cannot be estimated without including some prior information. Nevertheless, our model demonstrates that temporal variability in natural mortality strongly affects perceived variability in stock sizes. Thus, using estimation procedures that neglect temporal fluctuations in natural mortality may therefore give biased estimates of fluctuations in fish stock sizes. |
format |
Article in Journal/Newspaper |
author |
Aanes, Sondre Engen, Steinar Sæther, Bernt-Erik Aanes, Ronny |
author_facet |
Aanes, Sondre Engen, Steinar Sæther, Bernt-Erik Aanes, Ronny |
author_sort |
Aanes, Sondre |
title |
Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
title_short |
Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
title_full |
Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
title_fullStr |
Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
title_full_unstemmed |
Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
title_sort |
estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? |
publisher |
Canadian Science Publishing |
publishDate |
2007 |
url |
http://dx.doi.org/10.1139/f07-074 http://www.nrcresearchpress.com/doi/pdf/10.1139/f07-074 |
genre |
Arctic cod Arctic Gadus morhua Northeast Arctic cod |
genre_facet |
Arctic cod Arctic Gadus morhua Northeast Arctic cod |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 64, issue 8, page 1130-1142 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f07-074 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
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64 |
container_issue |
8 |
container_start_page |
1130 |
op_container_end_page |
1142 |
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1797575488511672320 |