A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality
Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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crcansciencepubl:10.1139/f2012-103 2023-12-17T10:33:26+01:00 A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality Trenkel, Verena M. Bravington, Mark V. Lorance, Pascal Walters, Carl 2012 http://dx.doi.org/10.1139/f2012-103 http://www.nrcresearchpress.com/doi/full-xml/10.1139/f2012-103 http://www.nrcresearchpress.com/doi/pdf/10.1139/f2012-103 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 69, issue 11, page 1881-1893 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2012 crcansciencepubl https://doi.org/10.1139/f2012-103 2023-11-19T13:39:09Z Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sample size for aggregated proportion-at-age data based on fitting Dirichlet-multinomial distributions to the raw sampling data. Parameter estimation is carried out by approximate likelihood. We use simulations to study parameter estimability and estimation bias of four model versions, including models treating mortality as fixed effects and misspecified models. All model versions were, in general, estimable, though for certain parameter values or replicate runs they were not. Relative estimation bias of final year total mortalities and depletion rates were lower for the proposed random effects model compared with the fixed effects version for total mortality. The model is demonstrated for the case of blue ling (Molva dypterygia) to the west of the British Isles for the period 1988 to 2011. Article in Journal/Newspaper Molva dypterygia Canadian Science Publishing (via Crossref) Canadian Journal of Fisheries and Aquatic Sciences 69 11 1881 1893 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Trenkel, Verena M. Bravington, Mark V. Lorance, Pascal A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sample size for aggregated proportion-at-age data based on fitting Dirichlet-multinomial distributions to the raw sampling data. Parameter estimation is carried out by approximate likelihood. We use simulations to study parameter estimability and estimation bias of four model versions, including models treating mortality as fixed effects and misspecified models. All model versions were, in general, estimable, though for certain parameter values or replicate runs they were not. Relative estimation bias of final year total mortalities and depletion rates were lower for the proposed random effects model compared with the fixed effects version for total mortality. The model is demonstrated for the case of blue ling (Molva dypterygia) to the west of the British Isles for the period 1988 to 2011. |
author2 |
Walters, Carl |
format |
Article in Journal/Newspaper |
author |
Trenkel, Verena M. Bravington, Mark V. Lorance, Pascal |
author_facet |
Trenkel, Verena M. Bravington, Mark V. Lorance, Pascal |
author_sort |
Trenkel, Verena M. |
title |
A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
title_short |
A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
title_full |
A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
title_fullStr |
A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
title_full_unstemmed |
A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
title_sort |
random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality |
publisher |
Canadian Science Publishing |
publishDate |
2012 |
url |
http://dx.doi.org/10.1139/f2012-103 http://www.nrcresearchpress.com/doi/full-xml/10.1139/f2012-103 http://www.nrcresearchpress.com/doi/pdf/10.1139/f2012-103 |
genre |
Molva dypterygia |
genre_facet |
Molva dypterygia |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 69, issue 11, page 1881-1893 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f2012-103 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
69 |
container_issue |
11 |
container_start_page |
1881 |
op_container_end_page |
1893 |
_version_ |
1785587436855754752 |