Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden
Aspects of the inter-relationship of krill Sound Scattering Layers (SSLs) and fish were examined in Ullsfjorden and Øksfjorden, northern Norway from 2 - 8 February 1980. Diel changes in the depth distribution and biomass of krill (Euphausiacea) were compared with the depth distribution and abundance...
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Institut für Meereskunde
1981
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Online Access: | https://oceanrep.geomar.de/id/eprint/56104/ https://oceanrep.geomar.de/id/eprint/56104/1/Falk-Petersen_S_1981.pdf |
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ftoceanrep:oai:oceanrep.geomar.de:56104 2023-05-15T17:39:22+02:00 Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden Falk-Petersen, S. Hopkins, C. C. E. 1981 text https://oceanrep.geomar.de/id/eprint/56104/ https://oceanrep.geomar.de/id/eprint/56104/1/Falk-Petersen_S_1981.pdf en eng Institut für Meereskunde https://oceanrep.geomar.de/id/eprint/56104/1/Falk-Petersen_S_1981.pdf Falk-Petersen, S. and Hopkins, C. C. E. (1981) Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden. Open Access Kieler Meeresforschungen - Sonderheft, 5 . pp. 191-201. cc_by_3.0 info:eu-repo/semantics/openAccess Article NonPeerReviewed 1981 ftoceanrep 2023-04-07T16:02:31Z Aspects of the inter-relationship of krill Sound Scattering Layers (SSLs) and fish were examined in Ullsfjorden and Øksfjorden, northern Norway from 2 - 8 February 1980. Diel changes in the depth distribution and biomass of krill (Euphausiacea) were compared with the depth distribution and abundance of gadoid fish using a pelagic capelin trawl, 38 and 120 kHz echosounders, and a digital echointegrator. Krill underwent vertical migrations from the surface at night to the fjord bottom at mid-day. A significant power curve relationship was found when catches of krill in the pelagic trawl (l·trawl h-1) were compared with volume backscattering (dB m-3) at 120 kHz, indicating that krill biomass can be reliably estimated using acoustic techniques. Krill were the dominant food item of fish caught with the pelagic trawl in the SSLs. Fish were nevertheless rare in these krill SSLs; the majority congregated under them, probably feeding extensively at their periphery. Interactions between krill and pelagic feeding gadoids in north Norwegian fjords are examined. Article in Journal/Newspaper North Norway Northern Norway Øksfjorden OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Norway |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Aspects of the inter-relationship of krill Sound Scattering Layers (SSLs) and fish were examined in Ullsfjorden and Øksfjorden, northern Norway from 2 - 8 February 1980. Diel changes in the depth distribution and biomass of krill (Euphausiacea) were compared with the depth distribution and abundance of gadoid fish using a pelagic capelin trawl, 38 and 120 kHz echosounders, and a digital echointegrator. Krill underwent vertical migrations from the surface at night to the fjord bottom at mid-day. A significant power curve relationship was found when catches of krill in the pelagic trawl (l·trawl h-1) were compared with volume backscattering (dB m-3) at 120 kHz, indicating that krill biomass can be reliably estimated using acoustic techniques. Krill were the dominant food item of fish caught with the pelagic trawl in the SSLs. Fish were nevertheless rare in these krill SSLs; the majority congregated under them, probably feeding extensively at their periphery. Interactions between krill and pelagic feeding gadoids in north Norwegian fjords are examined. |
format |
Article in Journal/Newspaper |
author |
Falk-Petersen, S. Hopkins, C. C. E. |
spellingShingle |
Falk-Petersen, S. Hopkins, C. C. E. Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
author_facet |
Falk-Petersen, S. Hopkins, C. C. E. |
author_sort |
Falk-Petersen, S. |
title |
Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
title_short |
Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
title_full |
Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
title_fullStr |
Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
title_full_unstemmed |
Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden |
title_sort |
zooplankton sound scattering layers in north norway fjords : interactions between fish and krill shoals in a winter situation in ullsfjorden and øksfjorden |
publisher |
Institut für Meereskunde |
publishDate |
1981 |
url |
https://oceanrep.geomar.de/id/eprint/56104/ https://oceanrep.geomar.de/id/eprint/56104/1/Falk-Petersen_S_1981.pdf |
geographic |
Norway |
geographic_facet |
Norway |
genre |
North Norway Northern Norway Øksfjorden |
genre_facet |
North Norway Northern Norway Øksfjorden |
op_relation |
https://oceanrep.geomar.de/id/eprint/56104/1/Falk-Petersen_S_1981.pdf Falk-Petersen, S. and Hopkins, C. C. E. (1981) Zooplankton sound scattering layers in North Norway fjords : interactions between fish and krill shoals in a winter situation in Ullsfjorden and Øksfjorden. Open Access Kieler Meeresforschungen - Sonderheft, 5 . pp. 191-201. |
op_rights |
cc_by_3.0 info:eu-repo/semantics/openAccess |
_version_ |
1766140125099589632 |