dc.contributor.author | Huse, Ingvar | |
dc.contributor.author | Ostrowski, Marek | |
dc.date.accessioned | 2008-08-06T07:54:31Z | |
dc.date.issued | 1998 | |
dc.identifier.uri | http://hdl.handle.net/11250/100145 | |
dc.description.abstract | A large concentration of wintering herring was surveys continuously with acoustics over 37 hours in a fjord in Northern Norway. 16 surveys of the same area were conducted. Total abundance and statistics were computed for each survey. Distribution graphs showd a clear diel variation, with deep daytime layers and more shallow night time distribution. Acoustically measured abundance at night was 50% of the daytime values. The results are discussed in terms of behaviour induced diel variation in acoustic backscattering, and potential influence on acoustic abundance measurements. | en |
dc.format.extent | 1405891 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | en |
dc.relation.ispartofseries | ICES CM documents | en |
dc.relation.ispartofseries | 1998/J:18 | en |
dc.title | Variation in acoustically measured abundance from repeated surveys of herring | en |
dc.type | Working paper | en |
dc.subject.nsi | VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 | |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 | |
dc.source.pagenumber | 8 s. | |