Skreitelling med ekkointegrator i Lofoten i 1972
A survey in the inner part of the Lofoten area was carried out vith R.V. «Johan Hjort» 14-15 March 1972. Abundance estimates and distribution charts were made on the basis of echo integrator deflections. The abundance estimates were low compared with those from 1971, probably because more of the cod...
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Language: | Norwegian Bokmål |
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Havforskningsinstituttet
1972
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Online Access: | http://hdl.handle.net/11250/113157 |
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ftimr:oai:imr.brage.unit.no:11250/113157 2023-05-15T14:30:27+02:00 Skreitelling med ekkointegrator i Lofoten i 1972 Counting of Arctic cod with echo integrator in Lofoten in 1972 Jakobsen, Tore Smedstad, Odd M. 1972 application/pdf http://hdl.handle.net/11250/113157 nob nob Havforskningsinstituttet Fisken og havet;1972 - Nr. 3 urn:issn:0071-5638 http://hdl.handle.net/11250/113157 s. 49-51 Research report 1972 ftimr 2021-09-23T20:15:02Z A survey in the inner part of the Lofoten area was carried out vith R.V. «Johan Hjort» 14-15 March 1972. Abundance estimates and distribution charts were made on the basis of echo integrator deflections. The abundance estimates were low compared with those from 1971, probably because more of the cod occurred in shallow waters out of reach from the echo sounder in 1972 than in 1971. Inside an area the abundance of cod was found to be much higher by day than by night. The difference was probably due to migration of the cod. Integration of echoes from the bottom in areas where the slopes were steep caused severe difficulties, and this problem will have to be solved in order to make the abundance estimates more accurate. The cod is probably never distributed in a way that makes covering of the total spawning stock during one survey possible. The distribution of the cod therefore probably causes the biggest problem in abundance estimation of the total spawning stock. Report Arctic cod Arctic Lofoten Institute for Marine Research: Brage IMR Arctic Lofoten |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
Norwegian Bokmål |
description |
A survey in the inner part of the Lofoten area was carried out vith R.V. «Johan Hjort» 14-15 March 1972. Abundance estimates and distribution charts were made on the basis of echo integrator deflections. The abundance estimates were low compared with those from 1971, probably because more of the cod occurred in shallow waters out of reach from the echo sounder in 1972 than in 1971. Inside an area the abundance of cod was found to be much higher by day than by night. The difference was probably due to migration of the cod. Integration of echoes from the bottom in areas where the slopes were steep caused severe difficulties, and this problem will have to be solved in order to make the abundance estimates more accurate. The cod is probably never distributed in a way that makes covering of the total spawning stock during one survey possible. The distribution of the cod therefore probably causes the biggest problem in abundance estimation of the total spawning stock. |
format |
Report |
author |
Jakobsen, Tore Smedstad, Odd M. |
spellingShingle |
Jakobsen, Tore Smedstad, Odd M. Skreitelling med ekkointegrator i Lofoten i 1972 |
author_facet |
Jakobsen, Tore Smedstad, Odd M. |
author_sort |
Jakobsen, Tore |
title |
Skreitelling med ekkointegrator i Lofoten i 1972 |
title_short |
Skreitelling med ekkointegrator i Lofoten i 1972 |
title_full |
Skreitelling med ekkointegrator i Lofoten i 1972 |
title_fullStr |
Skreitelling med ekkointegrator i Lofoten i 1972 |
title_full_unstemmed |
Skreitelling med ekkointegrator i Lofoten i 1972 |
title_sort |
skreitelling med ekkointegrator i lofoten i 1972 |
publisher |
Havforskningsinstituttet |
publishDate |
1972 |
url |
http://hdl.handle.net/11250/113157 |
geographic |
Arctic Lofoten |
geographic_facet |
Arctic Lofoten |
genre |
Arctic cod Arctic Lofoten |
genre_facet |
Arctic cod Arctic Lofoten |
op_source |
s. 49-51 |
op_relation |
Fisken og havet;1972 - Nr. 3 urn:issn:0071-5638 http://hdl.handle.net/11250/113157 |
_version_ |
1766304295282540544 |