Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020)
To support sustainable management of apex predator populations, it is important to estimate population size and understand the drivers of population trends to anticipate the consequences of human decisions. Robust population models are needed, which must be based on realistic biological principles a...
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Septentrio Academic Publishing
2021
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Online Access: | https://hdl.handle.net/11250/2979979 https://doi.org/10.7557/3.5794 |
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ftunivbergen:oai:bora.uib.no:11250/2979979 2023-05-15T15:59:54+02:00 Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) Smout, Sophie Murray, Kimberly Aarts, Geert Biuw, Martin Brasseur, Sophie Buren, Alejandro Empacher, Fanny Frie, Anne Kirstine Højholt Grecian, James Hammill, Mike Mikkelsen, Bjarni Mosnier, Arnaud Rosing-Asvid, Aqqalu Russell, Debbie Skaug, Hans Julius Stenson, Garry Thomas, Len Ver Hoef, Jay Witting, Lars Zabavnikov, Vladimir Øigård, Tor Arne Fernandez, Ruth Wickson, Fern 2021 application/pdf https://hdl.handle.net/11250/2979979 https://doi.org/10.7557/3.5794 eng eng Septentrio Academic Publishing urn:issn:1560-2206 https://hdl.handle.net/11250/2979979 https://doi.org/10.7557/3.5794 cristin:1980619 NAMMCO Scientific Publications. 2021, 12. Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no NAMMCO Scientific Publications 12 Journal article Peer reviewed 2021 ftunivbergen https://doi.org/10.7557/3.5794 2023-03-14T17:39:49Z To support sustainable management of apex predator populations, it is important to estimate population size and understand the drivers of population trends to anticipate the consequences of human decisions. Robust population models are needed, which must be based on realistic biological principles and validated with the best available data. A team of international experts reviewed age-structured models of North Atlantic pinniped populations, including Grey seal (Halichoerus grypus), Harp seal (Pagophilus groenlandicus), and Hooded seal (Cystophora cristata). Statistical methods used to fit such models to data were compared and contrasted. Differences in biological assumptions and model equations were driven by the data available from separate studies, including observation methodology and pre-processing. Counts of pups during the breeding season were used in all models, with additional counts of adults and juveniles available in some. The regularity and frequency of data collection, including survey counts and vital rate estimates, varied. Important differences between the models concerned the nature and causes of variation in vital rates (age-dependent survival and fecundity). Parameterisation of age at maturity was detailed and time-dependent in some models and simplified in others. Methods for estimation of model parameters were reviewed and compared. They included Bayesian and maximum likelihood (ML) approaches, implemented via bespoke coding in C, C++, TMB or JAGS. Comparative model runs suggested that as expected, ML-based implementations were rapid and computationally efficient, while Bayesian approaches, which used MCMC or sequential importance sampling, required longer for inference. For grey seal populations in the Netherlands, where preliminary ML-based TMB results were compared with the outputs of a Bayesian JAGS implementation, some differences in parameter estimates were apparent. For these seal populations, further investigations are recommended to explore differences that might result from the ... Article in Journal/Newspaper Cystophora cristata Harp Seal hooded seal North Atlantic Pagophilus groenlandicus University of Bergen: Bergen Open Research Archive (BORA-UiB) NAMMCO Scientific Publications 12 1 |
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Open Polar |
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University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
description |
To support sustainable management of apex predator populations, it is important to estimate population size and understand the drivers of population trends to anticipate the consequences of human decisions. Robust population models are needed, which must be based on realistic biological principles and validated with the best available data. A team of international experts reviewed age-structured models of North Atlantic pinniped populations, including Grey seal (Halichoerus grypus), Harp seal (Pagophilus groenlandicus), and Hooded seal (Cystophora cristata). Statistical methods used to fit such models to data were compared and contrasted. Differences in biological assumptions and model equations were driven by the data available from separate studies, including observation methodology and pre-processing. Counts of pups during the breeding season were used in all models, with additional counts of adults and juveniles available in some. The regularity and frequency of data collection, including survey counts and vital rate estimates, varied. Important differences between the models concerned the nature and causes of variation in vital rates (age-dependent survival and fecundity). Parameterisation of age at maturity was detailed and time-dependent in some models and simplified in others. Methods for estimation of model parameters were reviewed and compared. They included Bayesian and maximum likelihood (ML) approaches, implemented via bespoke coding in C, C++, TMB or JAGS. Comparative model runs suggested that as expected, ML-based implementations were rapid and computationally efficient, while Bayesian approaches, which used MCMC or sequential importance sampling, required longer for inference. For grey seal populations in the Netherlands, where preliminary ML-based TMB results were compared with the outputs of a Bayesian JAGS implementation, some differences in parameter estimates were apparent. For these seal populations, further investigations are recommended to explore differences that might result from the ... |
format |
Article in Journal/Newspaper |
author |
Smout, Sophie Murray, Kimberly Aarts, Geert Biuw, Martin Brasseur, Sophie Buren, Alejandro Empacher, Fanny Frie, Anne Kirstine Højholt Grecian, James Hammill, Mike Mikkelsen, Bjarni Mosnier, Arnaud Rosing-Asvid, Aqqalu Russell, Debbie Skaug, Hans Julius Stenson, Garry Thomas, Len Ver Hoef, Jay Witting, Lars Zabavnikov, Vladimir Øigård, Tor Arne Fernandez, Ruth Wickson, Fern |
spellingShingle |
Smout, Sophie Murray, Kimberly Aarts, Geert Biuw, Martin Brasseur, Sophie Buren, Alejandro Empacher, Fanny Frie, Anne Kirstine Højholt Grecian, James Hammill, Mike Mikkelsen, Bjarni Mosnier, Arnaud Rosing-Asvid, Aqqalu Russell, Debbie Skaug, Hans Julius Stenson, Garry Thomas, Len Ver Hoef, Jay Witting, Lars Zabavnikov, Vladimir Øigård, Tor Arne Fernandez, Ruth Wickson, Fern Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
author_facet |
Smout, Sophie Murray, Kimberly Aarts, Geert Biuw, Martin Brasseur, Sophie Buren, Alejandro Empacher, Fanny Frie, Anne Kirstine Højholt Grecian, James Hammill, Mike Mikkelsen, Bjarni Mosnier, Arnaud Rosing-Asvid, Aqqalu Russell, Debbie Skaug, Hans Julius Stenson, Garry Thomas, Len Ver Hoef, Jay Witting, Lars Zabavnikov, Vladimir Øigård, Tor Arne Fernandez, Ruth Wickson, Fern |
author_sort |
Smout, Sophie |
title |
Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
title_short |
Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
title_full |
Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
title_fullStr |
Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
title_full_unstemmed |
Report of the NAMMCO-ICES Workshop on Seal Modelling (WKSEALS 2020) |
title_sort |
report of the nammco-ices workshop on seal modelling (wkseals 2020) |
publisher |
Septentrio Academic Publishing |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2979979 https://doi.org/10.7557/3.5794 |
genre |
Cystophora cristata Harp Seal hooded seal North Atlantic Pagophilus groenlandicus |
genre_facet |
Cystophora cristata Harp Seal hooded seal North Atlantic Pagophilus groenlandicus |
op_source |
NAMMCO Scientific Publications 12 |
op_relation |
urn:issn:1560-2206 https://hdl.handle.net/11250/2979979 https://doi.org/10.7557/3.5794 cristin:1980619 NAMMCO Scientific Publications. 2021, 12. |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no |
op_doi |
https://doi.org/10.7557/3.5794 |
container_title |
NAMMCO Scientific Publications |
container_volume |
12 |
container_issue |
1 |
_version_ |
1766395791129182208 |