Near-bottom sampling with bottom and pelagic trawls
The Institute of Marine Research, Bergen, has carried out combined bottom trawl and acoustic surveys for cod and haddock in the Barents Sea - Svalbard area since 1981. These investigations have demonstrated clearly that the currently applied survey methods considerably underestimate the young age gr...
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ftimr:oai:imr.brage.unit.no:11250/104260 2023-05-15T15:38:54+02:00 Near-bottom sampling with bottom and pelagic trawls Engås, Arill Godø, Olav Rune 1987 application/pdf http://hdl.handle.net/11250/104260 eng eng ICES ICES CM Documents;1987/B:15 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104260 10 s. bottom trawl bunntrål pelagic trawl pelagisk trål sampling prøvetaking VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 Working paper 1987 ftimr 2021-09-23T20:15:53Z The Institute of Marine Research, Bergen, has carried out combined bottom trawl and acoustic surveys for cod and haddock in the Barents Sea - Svalbard area since 1981. These investigations have demonstrated clearly that the currently applied survey methods considerably underestimate the young age groups of cod. For haddock the survey abundance estimates have been considerably higher than those used in the stock assessment. Part of the problem has been shown to be be low bottom trawl efficiency for small fish. It has also been indicated that the pelagic trawl has low efficiency for cod. In this paper variation in length and species composition from samples taken with a bottom trawl and with a pelagic trawl on and off bottom are analyzed. Differences in sampling efficiency and the problems connected with combining data from different trawls during routine surveys are discussed. Report Barents Sea Svalbard Institute for Marine Research: Brage IMR Svalbard Barents Sea Bergen |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
bottom trawl bunntrål pelagic trawl pelagisk trål sampling prøvetaking VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 |
spellingShingle |
bottom trawl bunntrål pelagic trawl pelagisk trål sampling prøvetaking VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 Engås, Arill Godø, Olav Rune Near-bottom sampling with bottom and pelagic trawls |
topic_facet |
bottom trawl bunntrål pelagic trawl pelagisk trål sampling prøvetaking VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 |
description |
The Institute of Marine Research, Bergen, has carried out combined bottom trawl and acoustic surveys for cod and haddock in the Barents Sea - Svalbard area since 1981. These investigations have demonstrated clearly that the currently applied survey methods considerably underestimate the young age groups of cod. For haddock the survey abundance estimates have been considerably higher than those used in the stock assessment. Part of the problem has been shown to be be low bottom trawl efficiency for small fish. It has also been indicated that the pelagic trawl has low efficiency for cod. In this paper variation in length and species composition from samples taken with a bottom trawl and with a pelagic trawl on and off bottom are analyzed. Differences in sampling efficiency and the problems connected with combining data from different trawls during routine surveys are discussed. |
format |
Report |
author |
Engås, Arill Godø, Olav Rune |
author_facet |
Engås, Arill Godø, Olav Rune |
author_sort |
Engås, Arill |
title |
Near-bottom sampling with bottom and pelagic trawls |
title_short |
Near-bottom sampling with bottom and pelagic trawls |
title_full |
Near-bottom sampling with bottom and pelagic trawls |
title_fullStr |
Near-bottom sampling with bottom and pelagic trawls |
title_full_unstemmed |
Near-bottom sampling with bottom and pelagic trawls |
title_sort |
near-bottom sampling with bottom and pelagic trawls |
publisher |
ICES |
publishDate |
1987 |
url |
http://hdl.handle.net/11250/104260 |
geographic |
Svalbard Barents Sea Bergen |
geographic_facet |
Svalbard Barents Sea Bergen |
genre |
Barents Sea Svalbard |
genre_facet |
Barents Sea Svalbard |
op_source |
10 s. |
op_relation |
ICES CM Documents;1987/B:15 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104260 |
_version_ |
1766370309419565056 |