An evaluation of the methodology for prediction of capelin biomass
Ecosystem dynamics and optimal long-term harvest in the Barents Sea fisheries. Proceedings of the 11th Russian-Norwegian Symposium. Murmansk, 15-17 August 2005. The one-year prediction of capelin made as part of the assessment after the annual joint acoustic capelin survey during the autumn, is eval...
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ftimr:oai:imr.brage.unit.no:11250/107728 2023-05-15T15:38:57+02:00 An evaluation of the methodology for prediction of capelin biomass Bogstad, Bjarte Gjøsæter, Harald Ushakov, N.G. Prozorkevich, Dmitry 2005 513919 bytes application/pdf http://hdl.handle.net/11250/107728 eng eng IMR/PINRO IMR/PINRO Joint Report Series 2/2005 urn:issn:1502-8828 http://hdl.handle.net/11250/107728 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 Conference object 2005 ftimr 2021-09-23T20:14:54Z Ecosystem dynamics and optimal long-term harvest in the Barents Sea fisheries. Proceedings of the 11th Russian-Norwegian Symposium. Murmansk, 15-17 August 2005. The one-year prediction of capelin made as part of the assessment after the annual joint acoustic capelin survey during the autumn, is evaluated. Such predictions were made for the period from 1981 till present, and compared to observed stock sizes. The results show that the predictions underestimate the stock size in about half of the years and overestimate the stock size in the others, but in 18 out of the 23 years the observed stock sizes are within the 90% confidence interval of the predictions. It is found that there is a tendency for overestimating stock size in periods when the stock decreases and vice versa. The ratio between predicted and observed stock sizes is variable and some times quite high for stock sizes below one million tonnes (collapsed stock size) but varies between about 0.5 and 1.5 and is unrelated to stock size for larger stock sizes. These results are discussed in light of the various components of the models involved in the predictions. Conference Object Barents Sea Institute for Marine Research: Brage IMR Barents Sea Murmansk |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 |
spellingShingle |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 Bogstad, Bjarte Gjøsæter, Harald Ushakov, N.G. Prozorkevich, Dmitry An evaluation of the methodology for prediction of capelin biomass |
topic_facet |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 |
description |
Ecosystem dynamics and optimal long-term harvest in the Barents Sea fisheries. Proceedings of the 11th Russian-Norwegian Symposium. Murmansk, 15-17 August 2005. The one-year prediction of capelin made as part of the assessment after the annual joint acoustic capelin survey during the autumn, is evaluated. Such predictions were made for the period from 1981 till present, and compared to observed stock sizes. The results show that the predictions underestimate the stock size in about half of the years and overestimate the stock size in the others, but in 18 out of the 23 years the observed stock sizes are within the 90% confidence interval of the predictions. It is found that there is a tendency for overestimating stock size in periods when the stock decreases and vice versa. The ratio between predicted and observed stock sizes is variable and some times quite high for stock sizes below one million tonnes (collapsed stock size) but varies between about 0.5 and 1.5 and is unrelated to stock size for larger stock sizes. These results are discussed in light of the various components of the models involved in the predictions. |
format |
Conference Object |
author |
Bogstad, Bjarte Gjøsæter, Harald Ushakov, N.G. Prozorkevich, Dmitry |
author_facet |
Bogstad, Bjarte Gjøsæter, Harald Ushakov, N.G. Prozorkevich, Dmitry |
author_sort |
Bogstad, Bjarte |
title |
An evaluation of the methodology for prediction of capelin biomass |
title_short |
An evaluation of the methodology for prediction of capelin biomass |
title_full |
An evaluation of the methodology for prediction of capelin biomass |
title_fullStr |
An evaluation of the methodology for prediction of capelin biomass |
title_full_unstemmed |
An evaluation of the methodology for prediction of capelin biomass |
title_sort |
evaluation of the methodology for prediction of capelin biomass |
publisher |
IMR/PINRO |
publishDate |
2005 |
url |
http://hdl.handle.net/11250/107728 |
geographic |
Barents Sea Murmansk |
geographic_facet |
Barents Sea Murmansk |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_relation |
IMR/PINRO Joint Report Series 2/2005 urn:issn:1502-8828 http://hdl.handle.net/11250/107728 |
_version_ |
1766370387869827072 |