dc.contributor.author | Nakken, Odd | |
dc.contributor.author | Hylen, Arvid | |
dc.contributor.author | Ona, Egil | |
dc.date.accessioned | 2008-07-18T13:20:29Z | |
dc.date.issued | 1995 | |
dc.identifier.uri | http://hdl.handle.net/11250/107696 | |
dc.description | Precision and relevance of pre-recruit studies for fishery management related to fish stocks in the Barents Sea and adjacent waters. Proceeding of the sixth IMR-PINRO Symposium Bergen, 14-17 June 1994 | en |
dc.description.abstract | Acoustic and biological data collected during the international O-group surveys in 1992 and
1993 were used to estimate the abundance of O-group fish of 4 species; cod, haddock, redfish
and polar cod.
The abundances of O-group cod amounted to 107*109a nd 84 -lo9s pecimens in 1992 and 1993
respectively. These estimates are considerably higher than those arrived at by the swept
volume/area method when resonable values for trawl catch efficiencies were applied.
Instantaneous mortality rates of 8-9 were calculated from the acoustic estimates of O-group
in August and l-group in February for cod of the 1992 and 1993 year classes.
The acoustic estimates of O-group haddock abundance amounted to 12.109 and 8-lo9
specimens and the ratio between cod and haddock abundances were significantly higher for
the acoustic estimates than for the traditional indices of O-group abundance. For the two year
classes under observation instantaneous mortality rates of 4-5 were arrived at from the acoustic
estimates of O- and l-group haddock.
For O-group redfish the acoustic estimates of abundance amounted to 38-lo9 and 48.109
specimens in 1992 and 1993 respectively.
The estimates z,.rived at for O-group polar cod, 100.10~ and 62-lo9 specimens, were
underestimates due to insufficient acoustic coverage of the O-group polar cod distribution area
in both years. | en |
dc.format.extent | 579151 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | en |
dc.relation.ispartofseries | PINRO-IMR Symposium | en |
dc.relation.ispartofseries | 6 | en |
dc.subject | 0-gruppe | |
dc.subject | 0-group | |
dc.title | Acoustic estimates of 0-group fish abundance in the Barents Sea and adjacent waters in 1992 and 1993 | en |
dc.type | Conference object | en |
dc.source.pagenumber | s. 187-197 | |