Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond
This study investigates effects of subtle methodological choices on the estimation and biological interpretation of age, growth and reproductive parameters for harbour porpoises. The core analyses are based on a focal Norwegian data set built on samples from 134 harbour porpoises caught incidentally...
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Online Access: | http://dx.doi.org/10.1371/journal.pone.0301427 https://dx.plos.org/10.1371/journal.pone.0301427 |
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crplos:10.1371/journal.pone.0301427 2024-09-15T18:10:16+00:00 Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond Frie, Anne Kirstine Lindström, Ulf Fujiwara, Masami FRAM centre flagship project Norwegian Institute of Marine Research 2024 http://dx.doi.org/10.1371/journal.pone.0301427 https://dx.plos.org/10.1371/journal.pone.0301427 en eng Public Library of Science (PLoS) http://creativecommons.org/licenses/by/4.0/ PLOS ONE volume 19, issue 7, page e0301427 ISSN 1932-6203 journal-article 2024 crplos https://doi.org/10.1371/journal.pone.0301427 2024-07-09T04:07:00Z This study investigates effects of subtle methodological choices on the estimation and biological interpretation of age, growth and reproductive parameters for harbour porpoises. The core analyses are based on a focal Norwegian data set built on samples from 134 harbour porpoises caught incidentally in gillnet fisheries along the Norwegian coast during autumn 2016 and spring 2017. Two contrasting practices for interpretation of seasonal and ontogenetic characteristics of tooth growth layer formation resulted in significant age differences among spring samples of young porpoises and for older animals across seasons. In turn, these differences affected estimates of age at maturity and asymptotic lengths, respectively. We also found significant differences in male age at maturity between two well-documented maturity criteria and between mathematical estimators of age at maturity for both sexes. Two different criteria for corpus albicans classification furthermore resulted in different patterns of ovarian corpora accumulation, which may affect some estimates of fecundity rates and contaminant loads. Both corpora accumulation patterns were also found in reanalysed data from German and Greenlandic porpoises. Based on tabulated overviews of methodological choices made in previous harbour porpoise studies, we argue that several of the issues mentioned above have wider relevance and may affect the validity of meta-analyses as a tool for estimating harbour porpoise sensitivity to extrinsic pressures. Differences in cause of death (COD) composition between data sets can have a similar effect. We demonstrate this in a meta-analysis of published harbour porpoise pregnancy rates, showing significantly higher values for trauma-killed samples compared to samples comprising mixed COD categories. COD also affected the estimated impacts of three previously analysed extrinsic predictors as well as an added predictor for vessel noise levels. We discuss the potential contributions of methodological, biological and anthropogenic ... Article in Journal/Newspaper greenlandic Harbour porpoise PLOS PLOS ONE 19 7 e0301427 |
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English |
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This study investigates effects of subtle methodological choices on the estimation and biological interpretation of age, growth and reproductive parameters for harbour porpoises. The core analyses are based on a focal Norwegian data set built on samples from 134 harbour porpoises caught incidentally in gillnet fisheries along the Norwegian coast during autumn 2016 and spring 2017. Two contrasting practices for interpretation of seasonal and ontogenetic characteristics of tooth growth layer formation resulted in significant age differences among spring samples of young porpoises and for older animals across seasons. In turn, these differences affected estimates of age at maturity and asymptotic lengths, respectively. We also found significant differences in male age at maturity between two well-documented maturity criteria and between mathematical estimators of age at maturity for both sexes. Two different criteria for corpus albicans classification furthermore resulted in different patterns of ovarian corpora accumulation, which may affect some estimates of fecundity rates and contaminant loads. Both corpora accumulation patterns were also found in reanalysed data from German and Greenlandic porpoises. Based on tabulated overviews of methodological choices made in previous harbour porpoise studies, we argue that several of the issues mentioned above have wider relevance and may affect the validity of meta-analyses as a tool for estimating harbour porpoise sensitivity to extrinsic pressures. Differences in cause of death (COD) composition between data sets can have a similar effect. We demonstrate this in a meta-analysis of published harbour porpoise pregnancy rates, showing significantly higher values for trauma-killed samples compared to samples comprising mixed COD categories. COD also affected the estimated impacts of three previously analysed extrinsic predictors as well as an added predictor for vessel noise levels. We discuss the potential contributions of methodological, biological and anthropogenic ... |
author2 |
Fujiwara, Masami FRAM centre flagship project Norwegian Institute of Marine Research |
format |
Article in Journal/Newspaper |
author |
Frie, Anne Kirstine Lindström, Ulf |
spellingShingle |
Frie, Anne Kirstine Lindström, Ulf Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
author_facet |
Frie, Anne Kirstine Lindström, Ulf |
author_sort |
Frie, Anne Kirstine |
title |
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
title_short |
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
title_full |
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
title_fullStr |
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
title_full_unstemmed |
Exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in Norway and beyond |
title_sort |
exploring the effects of methodological choices on the estimation and biological interpretation of life history parameters for harbour porpoises in norway and beyond |
publisher |
Public Library of Science (PLoS) |
publishDate |
2024 |
url |
http://dx.doi.org/10.1371/journal.pone.0301427 https://dx.plos.org/10.1371/journal.pone.0301427 |
genre |
greenlandic Harbour porpoise |
genre_facet |
greenlandic Harbour porpoise |
op_source |
PLOS ONE volume 19, issue 7, page e0301427 ISSN 1932-6203 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1371/journal.pone.0301427 |
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PLOS ONE |
container_volume |
19 |
container_issue |
7 |
container_start_page |
e0301427 |
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1810447869831806976 |