Time-variant productivity in biomass dynamic models on seasonal and long-term scales
The productivity of fish populations varies naturally over time, dependent on integrated effects of abundance, ecological factors, and environmental conditions. These changes can be expressed as gradual or abrupt shifts in productivity as well as fluctuations on any time scale from seasonal oscillat...
Published in: | ICES Journal of Marine Science |
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Language: | English |
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2020
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ftdtupubl:oai:pure.atira.dk:publications/30a52f3e-b8c5-4745-adf1-442de22c4d15 2024-09-09T19:40:52+00:00 Time-variant productivity in biomass dynamic models on seasonal and long-term scales Mildenberger, Tobias Berg, Casper Willestofte Pedersen, Martin Wæver Kokkalis, Alexandros Nielsen, J. Rasmus 2020 application/pdf https://orbit.dtu.dk/en/publications/30a52f3e-b8c5-4745-adf1-442de22c4d15 https://doi.org/10.1093/icesjms/fsz154 https://backend.orbit.dtu.dk/ws/files/265048299/tvp_maintext.pdf eng eng https://orbit.dtu.dk/en/publications/30a52f3e-b8c5-4745-adf1-442de22c4d15 info:eu-repo/semantics/openAccess Mildenberger , T , Berg , C W , Pedersen , M W , Kokkalis , A & Nielsen , J R 2020 , ' Time-variant productivity in biomass dynamic models on seasonal and long-term scales ' , ICES Journal of Marine Science , vol. 77 , no. 1 , fsz154 , pp. 174-187 . https://doi.org/10.1093/icesjms/fsz154 Eastern Baltic cod (Gadus morhua) Fisheries management Fish stock assessment Maximum sustainable yield Population dynamics Seasonality SPiCT Surplus production model article 2020 ftdtupubl https://doi.org/10.1093/icesjms/fsz154 2024-07-08T23:51:45Z The productivity of fish populations varies naturally over time, dependent on integrated effects of abundance, ecological factors, and environmental conditions. These changes can be expressed as gradual or abrupt shifts in productivity as well as fluctuations on any time scale from seasonal oscillations to long-term changes. This study considers three extensions to biomass dynamic models that accommodate time-variant productivity in fish populations. Simulation results reveal that neglecting seasonal changes in productivity can bias derived stock sustainability reference levels and, thus, fisheries management advice. Results highlight the importance of biannual biomass indices and their timing relative to the peaks of the seasonal processes (i.e. recruitment, growth, mortality) for the estimation of seasonally time-variant productivity. The application to real-world data of the eastern Baltic cod ( Gadus morhua ) stock shows that the model is able to disentangle differences in seasonal fishing mortality as well as seasonal and long-term changes in productivity. The combined model with long-term and seasonally varying productivity performs significantly better than models that neglect time-variant productivity. The model extensions proposed here allow to account for time-variant productivity of fish populations leading to increased reliability of derived reference levels. Article in Journal/Newspaper Gadus morhua Technical University of Denmark: DTU Orbit ICES Journal of Marine Science |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
topic |
Eastern Baltic cod (Gadus morhua) Fisheries management Fish stock assessment Maximum sustainable yield Population dynamics Seasonality SPiCT Surplus production model |
spellingShingle |
Eastern Baltic cod (Gadus morhua) Fisheries management Fish stock assessment Maximum sustainable yield Population dynamics Seasonality SPiCT Surplus production model Mildenberger, Tobias Berg, Casper Willestofte Pedersen, Martin Wæver Kokkalis, Alexandros Nielsen, J. Rasmus Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
topic_facet |
Eastern Baltic cod (Gadus morhua) Fisheries management Fish stock assessment Maximum sustainable yield Population dynamics Seasonality SPiCT Surplus production model |
description |
The productivity of fish populations varies naturally over time, dependent on integrated effects of abundance, ecological factors, and environmental conditions. These changes can be expressed as gradual or abrupt shifts in productivity as well as fluctuations on any time scale from seasonal oscillations to long-term changes. This study considers three extensions to biomass dynamic models that accommodate time-variant productivity in fish populations. Simulation results reveal that neglecting seasonal changes in productivity can bias derived stock sustainability reference levels and, thus, fisheries management advice. Results highlight the importance of biannual biomass indices and their timing relative to the peaks of the seasonal processes (i.e. recruitment, growth, mortality) for the estimation of seasonally time-variant productivity. The application to real-world data of the eastern Baltic cod ( Gadus morhua ) stock shows that the model is able to disentangle differences in seasonal fishing mortality as well as seasonal and long-term changes in productivity. The combined model with long-term and seasonally varying productivity performs significantly better than models that neglect time-variant productivity. The model extensions proposed here allow to account for time-variant productivity of fish populations leading to increased reliability of derived reference levels. |
format |
Article in Journal/Newspaper |
author |
Mildenberger, Tobias Berg, Casper Willestofte Pedersen, Martin Wæver Kokkalis, Alexandros Nielsen, J. Rasmus |
author_facet |
Mildenberger, Tobias Berg, Casper Willestofte Pedersen, Martin Wæver Kokkalis, Alexandros Nielsen, J. Rasmus |
author_sort |
Mildenberger, Tobias |
title |
Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
title_short |
Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
title_full |
Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
title_fullStr |
Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
title_full_unstemmed |
Time-variant productivity in biomass dynamic models on seasonal and long-term scales |
title_sort |
time-variant productivity in biomass dynamic models on seasonal and long-term scales |
publishDate |
2020 |
url |
https://orbit.dtu.dk/en/publications/30a52f3e-b8c5-4745-adf1-442de22c4d15 https://doi.org/10.1093/icesjms/fsz154 https://backend.orbit.dtu.dk/ws/files/265048299/tvp_maintext.pdf |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Mildenberger , T , Berg , C W , Pedersen , M W , Kokkalis , A & Nielsen , J R 2020 , ' Time-variant productivity in biomass dynamic models on seasonal and long-term scales ' , ICES Journal of Marine Science , vol. 77 , no. 1 , fsz154 , pp. 174-187 . https://doi.org/10.1093/icesjms/fsz154 |
op_relation |
https://orbit.dtu.dk/en/publications/30a52f3e-b8c5-4745-adf1-442de22c4d15 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1093/icesjms/fsz154 |
container_title |
ICES Journal of Marine Science |
_version_ |
1809910347546492928 |