Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey
Since 1985 an acoustic survey specially designed for saithe has annually been conducted in October-November by the Institute of Marine Research (IMR) on the Norwegian near coastal banks. Since 1992 the survey has covered the area from the Varangerfjord close to the Russian border and southwards to 6...
Main Author: | |
---|---|
Format: | Report |
Language: | English |
Published: |
ICES
1997
|
Subjects: | |
Online Access: | http://hdl.handle.net/11250/105787 |
id |
ftimr:oai:imr.brage.unit.no:11250/105787 |
---|---|
record_format |
openpolar |
spelling |
ftimr:oai:imr.brage.unit.no:11250/105787 2023-05-15T15:12:23+02:00 Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey Nedreaas, Kjell Harald 1997 application/pdf http://hdl.handle.net/11250/105787 eng eng ICES ICES CM Documents;1997/Y:20 This report is not to be cited without prior reference to the author http://hdl.handle.net/11250/105787 22 s. acoustics akustikk saithe sei stock assessment bestandsberegning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Working paper 1997 ftimr 2021-09-23T20:16:12Z Since 1985 an acoustic survey specially designed for saithe has annually been conducted in October-November by the Institute of Marine Research (IMR) on the Norwegian near coastal banks. Since 1992 the survey has covered the area from the Varangerfjord close to the Russian border and southwards to 62°N. Because of the schooling behaviour of the saithe, the survey has tried to cover known saithe grounds rather than sailing regular survey tracks. This paper describes and tries to make a critical evaluation of this research survey with regards to survey design, timing, cruise tracks, stratification, fishing ground selection, and attribution of species composition to acoustic data. Including the acoustic survey in the XSA-tuning will slightly improve the statistical diagnosis of the assessment, and will lead to a small reduction in fishing mortality and a 3-10% larger juvenile biomass the four most recent years. For the prediction, however, the consequences are bigger. The input fishing pattem to the prediction and the stock size in numbers will lead to 10-12% larger total biomass, up to 40% higher SSB and up to more than 80% larger catches in the short term when the survey is included in the XSA-tuning. Out of presently three XSA tuning series, the acoustic survey is the only fishery independent one, it both improves the reliability and has a significant impact on the results. It is therefore concluded that the survey should continue to be conducted annually at more or less the same time of the year. Report Arctic Varangerfjord Varangerfjord* Institute for Marine Research: Brage IMR Arctic Fishing Ground ENVELOPE(-55.848,-55.848,49.550,49.550) |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
acoustics akustikk saithe sei stock assessment bestandsberegning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
spellingShingle |
acoustics akustikk saithe sei stock assessment bestandsberegning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Nedreaas, Kjell Harald Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
topic_facet |
acoustics akustikk saithe sei stock assessment bestandsberegning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
description |
Since 1985 an acoustic survey specially designed for saithe has annually been conducted in October-November by the Institute of Marine Research (IMR) on the Norwegian near coastal banks. Since 1992 the survey has covered the area from the Varangerfjord close to the Russian border and southwards to 62°N. Because of the schooling behaviour of the saithe, the survey has tried to cover known saithe grounds rather than sailing regular survey tracks. This paper describes and tries to make a critical evaluation of this research survey with regards to survey design, timing, cruise tracks, stratification, fishing ground selection, and attribution of species composition to acoustic data. Including the acoustic survey in the XSA-tuning will slightly improve the statistical diagnosis of the assessment, and will lead to a small reduction in fishing mortality and a 3-10% larger juvenile biomass the four most recent years. For the prediction, however, the consequences are bigger. The input fishing pattem to the prediction and the stock size in numbers will lead to 10-12% larger total biomass, up to 40% higher SSB and up to more than 80% larger catches in the short term when the survey is included in the XSA-tuning. Out of presently three XSA tuning series, the acoustic survey is the only fishery independent one, it both improves the reliability and has a significant impact on the results. It is therefore concluded that the survey should continue to be conducted annually at more or less the same time of the year. |
format |
Report |
author |
Nedreaas, Kjell Harald |
author_facet |
Nedreaas, Kjell Harald |
author_sort |
Nedreaas, Kjell Harald |
title |
Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
title_short |
Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
title_full |
Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
title_fullStr |
Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
title_full_unstemmed |
Evaluation of the North-East Arctic saithe (Pollachius virens) acoustic survey |
title_sort |
evaluation of the north-east arctic saithe (pollachius virens) acoustic survey |
publisher |
ICES |
publishDate |
1997 |
url |
http://hdl.handle.net/11250/105787 |
long_lat |
ENVELOPE(-55.848,-55.848,49.550,49.550) |
geographic |
Arctic Fishing Ground |
geographic_facet |
Arctic Fishing Ground |
genre |
Arctic Varangerfjord Varangerfjord* |
genre_facet |
Arctic Varangerfjord Varangerfjord* |
op_source |
22 s. |
op_relation |
ICES CM Documents;1997/Y:20 This report is not to be cited without prior reference to the author http://hdl.handle.net/11250/105787 |
_version_ |
1766343072916963328 |