dc.contributor.author | Slotte, Aril | |
dc.contributor.author | Runde, Arne | |
dc.contributor.author | Skaret, Georg | |
dc.contributor.author | Axelsen, Bjørn Erik | |
dc.contributor.author | Fernö, Anders | |
dc.contributor.author | Johannessen, Arne | |
dc.contributor.author | Nøttestad, Leif | |
dc.contributor.author | Øvredal, Jan Tore | |
dc.date.accessioned | 2007-08-07T10:03:23Z | |
dc.date.issued | 2005 | |
dc.identifier.uri | http://hdl.handle.net/11250/100773 | |
dc.description.abstract | Atlantic saithe (Pollachius virens) and Norwegian spring-spawning herring (Clupea harengus) represent two of the
most abundant and ecologically important fish species in the Northeast Atlantic. The two species co-occur in the
Vesterålen/Lofoten area during the wintering of herring, but the temporal and spatial overlap between species in
different scales as well as their trophic interactions is otherwise largely unknown. Saithe is a potentially important
predator on herring. In the present study we found the commercial catches of saithe off western Norway to be closely
related to the migration of herring into the coastal spawning grounds, indicating that saithe follow the high
concentrations of migrating herring. Acoustic surveys within a defined study area demonstrated that the species
overlapped spatially and temporarily. Degree of overlap varied both diurnally and with the maturity status of the herring
(pre-spawning, spawning or spent). Concurrent catches of saithe and herring from trawling and gillnets supported an
overlap also on the meso-scale. Observations on more fine-scaled behaviour obtained from an underwater rig with highsensity
cameras positioned in high-density areas of herring demonstrated that the distribution and behaviour of herring
and saithe was closely linked to the diel light cycle and spawning of herring. When looking at the actual outcome of the
interactions between the species on a kind of temporally, integrated spatial microscale, it was observed that stomachs of
large saithe (>50 cm) on average contained 2–3 herring, while the stomachs of smaller saithe were filled with herring
eggs. This suggests a considerable predation pressure by saithe on different life stages of herring. | en |
dc.format.extent | 133919 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | en |
dc.publisher | ICES | en |
dc.relation.ispartofseries | ICES CM documents | en |
dc.relation.ispartofseries | 2005/L:03 | en |
dc.subject | saithe | en |
dc.subject | sei | en |
dc.subject | herring | en |
dc.subject | sild | en |
dc.subject | akustikk | en |
dc.subject | acoustics | en |
dc.subject | catch | en |
dc.subject | fangst | en |
dc.title | Spatial and temporal overlap and trophic interactions between Atlantic Saithe (Pollachius virens) and Norwegian spring spawning herring (Clupea harengus) on herring spawning grounds | en |
dc.type | Working paper | en |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 | |
dc.subject.nsi | VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 | |
dc.source.pagenumber | Abstract only | en |